Bodies Human Exhibit Guide - Bodies Human Anatomy in Motion

BODIES HUMAN
ANATOMY IN MOTION
THE HUMAN MACHINE
Humans are unique machines which have the ability to move, think, manipulate objects,
build and repair themselves, grow and even reproduce to make more human machines.
Humans are much more than machines. If our machine parts, even just one, do not
work to their potential, our human existence is at stake.
This exhibit will help you understand the parts that make up your machine and how
these structures work together to keep you alive. You will .learn about what comprises
your body, as well as how these structures work. In the end, we hope you learn to
appreciate the human body.
EXPLORE, WONDER AND APPRECIATE…BODIES HUMAN
PURPOSE OF EXHIBIT AND GUIDE
BODIES HUMAN Anatomy in Motion gives the public a once-in-a-lifetime opportunity
to see, first-hand, the inner workings of real human bodies through authentic, preserved
human body specimens. The purpose of this guide is to help you understand the
specimens and how your body functions. The guide is intended to supplement the
magnificent anatomy by describing the different systems of the human body, present
trivia that you may not know and explain some medical applications of what you are
experiencing at the exhibit.
PLASTINATION PROCESS
Plastination, also called polymer impregnation, is a process that replaces the body’s
water and fat with plastics that harden into a fixed position. The advantage to this
process over using only formaldehyde to preserve bodies to be studied is that
plastinated bodies are dry, odorless and durable. The plastinated bodies are an
excellent teaching and research tool that will last for decades.
The process of plastination includes the following steps:
1. Each specimen is fixed using formalin (embalming fluid composed of
formaldehyde, water and menthol) to initially preserve the body or organ.
2. The specimen then is cleaned of lipids (fats) and excess material by washing the
specimen in cool running water for one to three days, depending on the size of
the specimen.
3. Next, the specimen is dehydrated. It is placed in acetone to remove water from
the cells and dissolve fat. Depending on the size and weight of the specimen, it
may take as many as three acetone baths (using new acetone) to complete this
step. The specimen should have one percent (1%) or less of water content to be
completely dehydrated.
4. The most important step is the replacement of the acetone, which occupies the
space once filled by water and lipids, by a curable polymer plastic. The
dehydrated specimen is placed in a liquid polymer and subjected to a vacuum
which draws out the acetone and leaves the polymer behind. You can witness
the exchange of acetone for the polymer by the bubbling action. Once the
bubbling stops, the exchange from acetone to the polymer is complete.
5. The final step is to remove the specimen from the polymer bath and let it drain.
Excess polymer is wiped from the specimen using paper towels. Then a thin
coating of catalyst is applied to the specimen and let cure. Once the specimen
has cured, it will last many years.
The plastination process takes about a week for a small organ and as long as a year for
an entire body.
OTHER IMPORTANT THINGS TO KNOW
Ø During the plastination process, some structures lose their color and would be
hard to identify. Different colored paints are used to identify different kinds of
structures.
· Blue indicates veins (blood vessels that go to the heart)
· Red indicates arteries (blood vessels that go away from the heart)
· Yellow indicates nerves
· Green indicates a tube or duct
Ø All the structures on the plastinates are the original tissue except for the eyes.
On most of the whole body specimens, the original eyes have been replaced.
Eyes do not retain their natural shape during the plastination process since the
eye contains so much water. The coronal face sections are an exception to this.
You can actually see the retina at the back of the eye on one of the face
sections.
Ø Some of the specimens are casting of blood vessels such as arteries, veins and
capillaries. Color castings are created by injecting saline into the main vessel or
tube of the organ or body part to flush away blood particles. A resin, mixed with
colored dye, is injected into the vessel or tube. The resin hardens and the
specimen is placed in a corrosive solution to remove the tissues. After some
weeks, the case is rinsed to remove residue and is then ready to display.
EXHIBIT DESCRIPTIONS
THINKER
For many, it is hard to comprehend the complexity of the brain and how it allows us to
perform basic life functions such as breathing, heart contraction, digestion, and
movement, while we reason, problem solve and remember. The large, folded part of
the brain you can see vividly on the Thinker is the cerebrum. The outer, folded portion
is the cerebral cortex, which allows us to be conscious, control motor functions and be
aware of sensations such as vision, hearing, and taste. The longitudinal fissure
physically separates the right and left cerebral hemispheres, the two sides of the brain.
Another visible structure at the back of the brain is the cerebellum. This structure helps
the Thinker balance on the stool. The cerebellum coordinates body movements that are
directed by other brain structures, like the cerebrum and helps maintain posture. Just
recently, scientists discovered that the cerebellum also plays a role in language,
problem solving and task planning.
The other main part of the brain, not seen on the Thinker, is the brainstem, which joins
with the spinal cord that runs down the back. The brainstem consists of the midbrain,
pons and medulla oblongata and controls basic life functions such as breathing and
heartbeat. Many nerves that go to the face and head originate from the brainstem. You
can see these nerves on the side of the Thinker’s face.
From the brainstem, the spinal cord runs down the entire back of the Thinker. The
spinal cord is the vital link between our environment and our brain interpreting
sensations. The spinal cord is like a relay system. Sensory nerves in your skin, eyes,
ears, nose and tongue send information to the spinal cord which then relays the
information to the brain. Sometimes the information is interpreted by the spinal cord
directly, sending an impulse to a muscle to contract. This is called a reflex. You can
see the many spinal nerves coming off the spinal cord on the back of the Thinker.
Thirty-one pairs of spinal nerves, each containing thousands of nerve fibers, attach to
the spinal cord. Notice the large sciatic nerves, the largest and longest nerves of the
body, that run down each leg.
Fact: 70% of all the sensory neurons (nerve cells) in your body are located in the retina
at the back of the eye.
Fact: The human brain of one individual generates more electrical impulses in one day
than all the telephones of the world. Nervous impulses travel on average 224 miles an
hour.
Fact: There are 45 miles of sensory nerves in the skin that send temperature, pain and
pressure information to the brain.
MEDICAL APPLICATION
Strokes are the most common disorders of the nervous system. A stroke occurs when
there is a blockage or interruption of blood flow to a part of the brain that results in death
of brain tissue due to lack of oxygen.
Multiple sclerosis is a disabling disorder that affects the nerve cells of the central
nervous system (brain and spinal cord). The immune system attacks the fatty,
protective covering around nerve cells. The fatty substance, called myelin, is replaced
with scar tissue and can lead to numbness, paralysis and loss of vision.
Alzheimer’s is a progressive and fatal brain disease. As many as 5 million Americans
are living with Alzheimer’s disease today. Alzheimer's destroys brain cells, causing
problems with memory, thinking and behavior severe enough to affect work, hobbies or
social life. It is the seventh-leading cause of death in the United States. Two abnormal
structures called plaques and tangles play a role in damaging and killing nerve cells.
Plaques are proteins that build up between nerve cells in the brain. Tangles are
different proteins that develop in dying nerve cells. We all have plaques and tangles in
our brains, but Alzheimer’s patients develop more and at a faster rate. The plaques and
tangles tend to form in a predictable pattern, beginning in areas important in learning
and memory, and then spreading to other regions which eventually cause death. There
is no cure for Alzheimer’s, but medication can help with symptoms.
SKELETON
Although this body is without its skin, muscles and major organs, it shows a very
important tissue of the human body; bone. It seems impossible, but bone is very much
alive. Bone consists of living cells called osteocytes. These cells are responsible for
depositing minerals, like calcium and magnesium, to make the bone hard. Your skeleton
provides the framework that supports your body, provides for a place for muscles to
attach for movement, helps to protect vital organs such as the brain, heart, lungs and
spinal cord and stores essential minerals needed for certain chemical reactions such as
muscle contraction. In addition, there is bone marrow in the middle of your bones that
contains different types of cells. Yellow marrow stores some of your fat while red
marrow contains stem cells that become your blood cells.
Cartilage is also included as part of your skeletal system. Cartilage has a different
structure than bone and serves more of a cushioning function. Cartilage consists of 60%
to 80% water, which gives it the ability to spring back to its original shape after being
compressed. Just bend your ear and let go and you can experience the flexibility of
cartilage. Essential cartilage is found between the sternum (breast bone) and the ribs,
between the vertebrae, on the ends of bones at moveable joints, ears, and at the end of
the nose.
Ligaments are another important tissue that makes up your skeletal system. Ligaments
are tough straps of tissue that hold bones together at joints. Without ligaments and
tendons, which connect muscles to bones, we would just be a “bag of bones.”
The heart the skeleton is holding is essential to the development of the skeleton. The
heart pumps the blood, which supplies the bone cells with needed nutrients and oxygen.
The blood carries the minerals that are deposited in the bone tissue. The blue side of
the heart (right side) contains deoxygenated blood and the red side of the heart (left
side) contains oxygenated blood.
Fact: At birth you have 300 bones. Many of these bones fuse together, making the
adult total of 206 bones.
Fact: The word skeleton is Greek, meaning “dried-up” body or “mummy.”
Fact: The femur, the big thigh bone, is the strongest bone in the human body.
Fact: The skeleton makes up 20% of your body mass.
Fact: The only bone in the body that is not connected to another bone is the hyoid, a
bone located at the base of the tongue between your lower jaw bone and voice box.
SKELETAL SYSTEM
MEDICAL APPLICATION
The most common congenital abnormality is cleft palate, in which the right and left hard
palate bone in the upper part of the mouth fails to grow, creating an opening between
the nasal cavity and mouth. This condition makes it difficult for the child to eat and has
to be repaired usually around 9 to 12 months of age.
Recently, it has been discovered that cleft palate risk can be reduced if the mother
takes multivitamins containing folic acid. Folic acid, also known as folate, is also found
in leafy vegetables such as spinach and lettuce, dried beans and peas, sunflower seeds
and fortified cereals. Folic acid also has been found to decrease the risk of neural tube
defects such as spina bifida, heart disease, stroke and cancer.
A new technique in medicine is to have a patient donate their own cartilage cells;
then these cells are cultured (grown) to increase their number. These new cartilage
cells are grafted onto joint surfaces, which help fill small holes or breaks in the articular
cartilage of the knee. Researchers are trying to grow thicker sheets of cartilage that
could be used to cover entire joint surfaces.
MALE AND FEMALE PELVIS
The female pelvis is adapted for childbearing. The female pelvis is broader and the
pubic angle is more rounded, at an 80- to 90-degree angle. The male pelvis is thicker
and heavier bone to support the larger build of men. The pubic arch is more of an acute
angle, at only 50 to 60 degrees. These differences are so consistent between men and
women that an anatomist can determine the sex of a skeleton with 90% certainty merely
by examining the pelvis.
MUSCLES, ARTERIES, NERVES AND TENDONS
OF UPPER LIMB, HAND AND LOWER MUSCLES
The specimen in this display shows the complexity of the muscles (pink in color),
arteries (red), veins (blue), nerves (yellow) and tendons (white) that connect muscles to
bones. Multiple structures are needed to perform the variety of movements that are
accomplished by the hand, arm and legs.
JOINTS
The hip joint is an example of a ball and socket joint made up of the femur and pelvic
bone. Ball and socket joints allow for movement in all directions including rotation. The
shoulder joint is also a ball and socket joint.
The knee joint is a hinge joint. Movement is allowed only in one plane, like a door on a
hinge. The knee joint allows for movement between the femur and tibia. The elbow
joint is another example of a hinge joint.
The joint between your finger bones (phalanges) at the knuckles is called a condyloid
joint. Condyloid joints allow for side to side movement (spreading your fingers) and
back and forth movement (flexing and extending your fingers).
NERVES, ARTERIES AND VEINS OF ARM, HAND, LEG AND FOOT
These specimens show the deep nerves, arteries and veins in the arm, hand, leg and
foot.
BASKETBALL PLAYER
Everyone loves to watch a talented athlete, like a basketball player, excel at his or her
game. To be an exceptional athlete, one must fine-tune their skeletal muscles, the
muscles responsible for movement. Muscles are also responsible for maintaining
posture, stabilizing joints, and heat production (that is why you shiver on a cool day).
On the Basketball Player, we can see the large quadriceps muscles (rectus femoris is
part of the quadriceps) that help to extend the knee to sprint down the court. Other
muscles responsible for running include the large gluteus maximus (buttock muscle),
hamstrings (large group of back, upper thigh muscles), gastrocnemius (calf muscle) and
soleus (muscle underneath calf muscle).
Have you ever wondered why you are so sore when you first start to exercise? The
reason your muscles are so stiff and sore is because you are not getting enough
oxygen to your muscles, so your muscle cells have to utilize your food energy without
the help of enough oxygen. This process, called anaerobic respiration, creates a
chemical called lactic acid that has a difficult time leaving the muscle cells. This makes
your muscles more fatigued and extremely sore. The best thing to do is to keep
moving, which helps to get the lactic acid out of your muscles.
So why do you get less sore each time you continue to exercise? Over time, your
muscle tissue will develop more blood vessels, called capillaries, to get more oxygen to
your muscle cells. The more aerobic exercise you do, getting your heart and breathing
rates to increase, the more efficient your lungs and heart become to supply your active
muscles with the food and oxygen they need to keep your muscles contracting.
Have you ever experienced a tingling or numbness in your hand and wrist, or a sudden,
sharp, piercing pain that shoots through the wrist up your arm? Could it be a cramp?
More likely you have carpal tunnel syndrome, a painful progressive condition caused by
compression of a key nerve in the wrist. Carpal tunnel syndrome occurs when the
median nerve, which runs from the forearm into the hand, becomes pressed or
squeezed at the wrist. The median nerve controls sensations to the palm side of the
thumb and fingers (although not the little finger), as well as impulses to some small
muscles in the hand that allow the fingers and thumb to move. The carpal tunnel - a
narrow, rigid passageway of ligament and bones at the base of the hand - houses the
median nerve and tendons. Sometimes, thickening from irritated tendons or other
swelling narrows the tunnel and causes the median nerve to be compressed. The result
may be pain, weakness, or numbness in the hand and wrist, radiating up the arm.
Fact: There are more than 650 muscles in the human body.
Fact: Even though the brain is only 2 percent of our total body weight, it uses 20
percent of the body’s oxygen and food resources.
MEDICAL APPLICATION
There are two types of muscle fibers, fast and slow twitch. Your endurance or speed
when running is determined by the proportion of the two types of muscle fibers. Slow
twitch muscles are more efficient at using oxygen to generate more fuel for continuous,
extended muscle contractions over a long time. They fire more slowly than fast twitch
muscles and can go for a long time before they fatigue. Slow twitch muscles are great at
helping athletes run marathons and bicycle for hours.
Fast twitch muscles use anaerobic metabolism, without oxygen, to create energy for
muscle contraction. They are much better at generating short bursts of strength or
speed than slow muscles. However, they fatigue more quickly. Fast twitch muscles
generally produce the same amount of force per contraction as slow muscles, but they
get their name because they are able to fire more rapidly. Having more fast twitch fibers
can be an asset to a sprinter since he or she needs to quickly generate a lot of force.
Research has found our muscle fiber type may influence the sports in which we
naturally excel. Olympic athletes tend to fall into sports that match their predominant
type of muscle fibers. Olympic sprinters have been shown to possess about 80 percent
fast twitch fibers, while those who excel in marathons tend to have 80 percent slow
twitch fibers.
NERVES, ARTERIES and VEINS OF ARM, HAND AND FOOT
Notice the nerves of the foot, called the plantar branches. The nerve visible in the arm
and hand is the large radial nerve of the upper and lower arm that radiates into the
hand.
SPINAL CORD AND NERVES OF ADULT AND CHILD
The specimen with the skull attached is of an adult. Notice how there is not much
difference between the lengths of the child’s and adult’s spinal cord. The spinal cord
stops growing in early childhood. The nerves coming off the spinal cord are called
spinal nerves. Some nerve fibers of the spinal nerves send information to the Central
Nervous System (brain and spinal cord) from specialized nerves that sense information
about the environment (temperature, pain, or pressure) or information about organs.
Other nerve fibers send information back to a muscle or gland to respond.
THE OLYMPIAN
Look carefully at the Olympian and you can see the different layers that compose
the human body. The outside of the body is called the integumentary system which is
made of epithelial tissue which you might know as epidermis, the top layer of the skin.
The layer underneath the epidermis is connective tissue called the dermis.
The connective tissue contains a protein called collagen that makes the skin tough and
protective. Another kind of protein called elastin makes the skin elastic. This layer also
contains many nerve endings that send information about the environment to the brain
and blood vessels to help dissipate heat.
The skin is the largest organ in your body whose main functions include:
waterproofing your body by preventing water loss, helping to keep ultraviolet rays from
damaging underlying tissues and preventing invading pathogens (disease causing
organisms such as bacteria and viruses) and harmful chemicals from entering your
body. Other structures, such as the sweat glands, help to cool the skin. We would not
be able to maintain a constant body temperature without our skin.
The dermal connective tissue layer lies under the hypodermis which is made of
connective tissue that attaches the skin to the muscles. This is also where a lot of fat,
called adipose, is deposited. Fat is necessary for insulating the body to help prevent
heat loss and to store extra energy.
Skeletal muscle is attached to the hypodermis. Skeletal muscle is appropriately
named since it is attached to bones. The muscles are attached to the bones by
tendons. Bones, another type of connective tissue, make up our innermost framework.
Can you imagine what we would be like without our skeleton to support our outer
tissues? We would be just a mass of soft tissues.
Find the following layers on the Olympic Champion: skin (epidermis and dermis),
hypodermis, muscle tissue and bone tissue. Notice the numerous blood vessels
(arteries in red and veins in blue) and nerves (in yellow) that run through the tissue
layers. The green colored tubes in the cheek area are the parotid ducts that deliver
saliva from a salivary gland (parotid gland) to the mouth.
Fact: Skin makes up about 7% of your body weight, weighing between 5 ½ to 10
pounds.
Fact: Skin would cover an area of approximately 14 to 25 square feet if spread out flat.
Fact: On average, a person sheds more than 100 pounds of skin in a lifetime.
Fact: There are approximately 5 million hairs all over a human body and about 100,000
hairs on your head.
Fact: A square inch of human skin consists of 20 feet of blood vessels.
Fact: Goose bumps are caused by a tiny muscle called the arrector pili muscle that is
attached to the hair follicle in which the hair grows. When this muscle contracts it
makes the hair follicle rise causing the bump on the skin.
Fact: Perspiration does not have a smell. Bacteria that live on the skin create the odor
that so many people attribute to sweat. Certain sweat glands, primarily in the armpit
and groin area, secrete a fatty sweat while those in other areas of our skin secrete a
more watery sweat. The bacteria breaks down the fat in the sweat, creating the odor.
MEDICAL APPLICATION
Studies have shown that vernix, the white cheesy substance that covers babies at birth,
should not be wiped off, but left intact. Vernix has been described as nature’s perfect
moisturizer and future skin products may include the components of vernix.
Persistent friction causes a thickening of the epidermis called a callus. A callus is an
adaptation to protect the underlying skin layers. A blister, on the other hand, is caused
by short-term but severe friction. When a blister forms, the epidermis separates from
the lower dermis and the pocket created fills with fluid. The fluid can be clear and
watery, or bloodlike, in the case of a blood blister, or pus-filled if it is infected.
HEARTS SHOWING GREAT VESSELS, PAPILLARY MUSCLE AND VALVES
One of the hearts shows the great vessels, including the coronary arteries and cardiac
veins. The coronary arteries are the important body vessels that supplies the heart with
the essential nutrients and oxygen it needs to keep contracting. The cardiac veins drain
the blood back into the heart.
The two halves of the dissected heart show the papillary muscles and valves on the
inside of the heart. These muscles connect to tough chordae tendineae (look like
strings) which act like guy wires that anchor the cusps (parts) of the heart valves. When
the papillary muscles contract, the chordae tendineae fibers pull the valves shut to
prevent the blood from back flowing.
The single valve is the aortic semilunar valve between the left ventricle (bottom
chamber on left side of heart) and the aorta (the largest artery of the body).
DURA MATER AND BRAIN
The horizontal sections of the brain show the different layers of gray and white matter.
The gray matter is stained a darker color. If we could see a section of spinal cord, the
white matter would be on the outside and the gray matter on the inside. White matter is
myelinated; the nerve cells have a fatty substance called myelin around them that
speeds up transmission of the impulse.
The cerebellum controls balance, coordination and posture.
The dura mater is the protective membrane that protects the brain.
The left cerebral hemisphere is just half of the cerebrum. The two cerebral
hemispheres account for 83% of the total brain mass. The cerebrum has many grooves
on its external surface. The cerebral cortex on the outside of the cerebrum is made of
gray matter. You can see this on the horizontal sections.
SINGER
Sound would not be possible without the movement of air in and out of the human body.
The anatomy of producing sound is simple, but very impressive. Sound is first brought
into the lungs by the contraction of the diaphragm, the thin muscle that divides the
thoracic cavity (containing heart and lungs) and the abdominal cavity (containing the
stomach, liver, intestines, urinary bladder and reproductive organs). When the
diaphragm contracts, it moves downward and the rib cage moves outward to increase
the space in the thoracic cavity. The increase in space in this cavity decreases the
pressure in the lungs. This process is much like how the wind blows from a high
pressure system to a low pressure system. The diaphragm creates the low pressure
system making air rush in without us having to forcefully suck air in. The air will flow
through the mouth and nose (preferably the nose because there is more surface area to
warm the air plus nose hairs and mucus to filter the air). The air continues flowing on to
the pharynx (throat), the larynx (voice box membranes that vibrate to produce sound),
trachea (windpipe), bronchi tubes and finally the alveoli (air sacs where oxygen and
carbon dioxide is exchanged with the capillaries).
To create the pressure differences, the diaphragm must receive the message to
contract or relax. On the Singer you can see the yellow nerves that send the “message”
to muscles and organs to respond. The respiratory system receives the “message”
from the brain and spinal cord via the phrenic nerve.
When the Singer wants to make sound, the diaphragm relaxes, moving upward, and the
rib cage moves inward, creating a higher pressure than outside the body. Air then
moves out of the respiratory system. When air passes slowly across the vocal cords,
they are snapped, gently creating a soft sound. When the air moves quickly, causing
the vocal cords to snap together forcefully, it creates a loud sound. The faster the cords
open and close, the higher the pitch will be.
The vocal cords produce the “buzzing” sound of noise while other anatomical structures
resonate the sound for better sound quality. Structures such as the tongue, palate on
the roof of the mouth, nasal cavity, sinus cavities and pharynx serve as resonators that
help
to
refine
the
quality
of
singing
or
speech.
Look at the Singer’s head, where the skull has been removed. You can see the
meninges, the protective membranes around the brain. The layer you can see that
looks like a sac is called the dura mater. These membranes cover and protect the
brain, enclose and protect the blood vessels that supply the brain and contain the
cerebrospinal fluid. Infection of the meninges is called meningitis.
Fact: Vocal cords open and close 100 times per second during normal speech.
Fact: Lungs contain almost 1500 miles of air passages to get to the 300 million alveoli
(tiny air sacs where oxygen is exchanged for carbon dioxide).
Fact: Hiccups result when the phrenic nerve causes the abrupt, rhythmic contraction of
the diaphragm. This response usually is caused by irritation of the diaphragm or
stomach from spicy food or an acidic, carbonated beverage.
Fact: Adult humans take a breath 23,000 times a day on average.
Fact: The left lung is smaller than the right lung to make room in the thoracic cavity for
the heart.
MEDICAL APPLICATION
Lung cancer constitutes 1/3 of all cancer deaths in the U.S. Lung cancer is the most
common malignant cancer in both men and women. Smoking is the main contributor to
lung cancer. In the United States, smoking is estimated to account for 87% of lung
cancer cases (90% in men and 85% in women). Cigarette smoke contains over 60
known carcinogens (cancer-causing agents). Lung cancer often spreads
(metastasizes) to other parts of the body, including the brain, bones and liver.
Treatment options typically include one or more treatments, including surgery,
chemotherapy, radiation therapy or targeted drug therapy.
DISSECTION OF THE NECK AND FACIAL ARTERIES AND
VEINS AND SECTION TO SHOW CAVITIES IN HEAD
On one side of the specimen you can clearly see the carotid artery (red) that branches
off to supply the brain with oxygenated blood. The other blood vessels in blue are
veins. The large jugular veins drain the deoxygenated blood from the head back to the
heart.
On the other side of the specimen, the majority of structures have been removed to see
the cavities of the head. In the cranial cavity you can see where the cerebrum would
be within the dura mater on the top and the cerebellum on the bottom. Also visible is
the nasal cavity. It is more advantageous to bring air in through the nasal cavity
because of all the folds within the nose. These folds increase the surface area which
helps to warm and filter the air before it gets to the lungs.
Find the esophagus - the tube that leads from the pharynx (throat) to the stomach.
Can you find the epiglottis - the flap of tissue that covers the trachea? The epiglottis
prevents food and drink from entering the lungs?
LUNGS, LARYNX AND TRACHEA
The lungs contain the air sacs called alveoli. These tiny sacs exchange oxygen for
carbon dioxide in each breath we take. The larynx contains the voice box that helps us
make sound. The trachea, also known as the windpipe, is the tube that leads from the
larynx into the lungs. It is held open with C-shaped cartilage rings. If you touch the
front of your neck, you can feel these tough cartilage rings.
The arteriovenous cast of the lungs shows the numerous blood vessels within the
lungs.
LUNG WITH BRONCHIAL TREE, DISSECTED TONGUE,
LARYNX AND THYROID GLAND
The bronchial tree consists of the set of tubes that bring air in and out of the lungs.
The tubes consist of the trachea, bronchi, bronchiole tubes and terminal bronchioles.
Notice the thyroid gland on the sides of the trachea, just below the larynx. The thyroid
gland is part of the endocrine system and secretes hormones responsible for
maintaining your metabolism (how you utilize your food for energy). Your thyroid
needs the element iodine to make the thyroid hormones properly. If you are deficient in
iodine, you may develop goiter. Goiter is not very common in the United States since
iodine has been added to table salt. The picture below shows other hormone
producing glands of the endocrine system.
LIVER, GALL BLADDER, SPLEEN AND PANCREAS
In this display you can see the position of the liver, gallbladder, spleen and pancreas.
The spleen is located on the left side of your body next to the stomach.
The liver is the largest gland of the body. It performs more than 500 functions such as
producing bile which emulsifies fat (breaks apart fat particles and coats the fat
molecules so they stay mixed with the enzyme rich, liquefied food in small intestines).
The liver also picks up excess glucose and stores the extra sugar as glycogen. In
addition the liver stores certain vitamins and detoxifies poisons and drugs in the blood.
The gall bladder stores the bile the liver produces.
The spleen is the largest lymphatic organ. The spleen is responsible for helping the
immune system fight infection by removing bacteria, viruses and toxins. The spleen
also removes dead blood cells.
The pancreas is an endocrine gland (produces hormones directly into the blood
stream) and an exocrine gland (produces and secretes enzymes and other chemicals
through ducts into the small intestine). The pancreatic hormone called insulin helps to
lower blood sugar levels by signaling the cells to utilize glucose from the blood. The
pancreatic enzymes produced help the small intestine breakdown carbohydrates, fats
and proteins.
LIVER
When looking at the liver in this display, notice its numerous blood vessels. Blood from
the small intestines, which is carrying the absorbed nutrients from the digestive system,
is taken to the liver so the nutrients can be modified before going to the body cells.
ORGANS OF THE THORACIC AND ABDOMINAL CAVITIES INCLUDING
STOMACH, SMALL INTESTINE and COLON (LARGE INTESTINE)
On the dissected stomach you can see the folds on the interior of the organ. These
folds are called rugae and allow the stomach to expand. The stomach can easily hold
about 1 quart of food, but has the ability to expand to hold a gallon of food and drink.
The stomach meets the esophagus, the tube that connects the mouth and throat with
the stomach, at a valve called the cardiac sphincter (lower esophageal sphincter). This
prevents food from going back up the esophagus. At the bottom of the stomach, there
is another valve which controls the amount of food that passes from the stomach to the
small intestines. It is called the pyloric sphincter. Some protein digestion occurs in the
stomach.
The large specimen in the middle shows the organs in the upper thoracic cavity and
lower abdominal cavity. The heart is located in the center of the thoracic cavity, but is
offset to the left side, making the left lung a little bit smaller than the right lung. You
can readily see these lungs came from a smoker.
In the abdominal cavity, the large liver is seen under the diaphragm, the muscle that
separates the thoracic cavity from the abdominal cavity. The small intestines can be
seen towards the bottom and the large intestines off to the side. The large membrane
that is covering the digestive organs is called the omentum.
The small intestine is composed of three sections; duodenum, jejunum and ileum.
Enzymes secreted by the intestinal cells help to break down carbohydrates, lipids and
proteins. The small intestine is the organ in which most of the food digestion and
nutrient absorption occurs.
The colon is another name for large intestine. The colon absorbs water and provides a
habitat for intestinal bacteria that decomposes food we cannot digest. This action also
yields certain B vitamins and vitamin K.
ARTERIOVENOUS CAST OF BRONCHIAL TREE
This display shows the vast amount of blood vessels within the respiratory system.
The blue blood vessels indicate the path the blood coming from the heart will take to
pick up oxygen from the lungs. The red blood vessels show the path the blood will take
to get back to the heart so the oxygenated blood can be pumped to all the body cells.
ARTERIOVENOUS CAST OF THE PLACENTA
The placenta is the structure that connects the mother with the fetus developing within
her uterus. The umbilical cord runs from the fetus to the placenta which is attached to
the uterine wall. The placenta is an organ composed of tissue from both the mother
and fetus. The blood between mother and fetus do not mix. Instead, the nutrients and
oxygen diffuse from the mother’s blood supply to that of the fetus. Waste and
hormones from the fetus diffuses from the blood vessels of the fetus within the placenta
to the mother’s blood.
ARTERIOVENOUS CAST OF THE HEART
The large red blood vessel coming from the left side of the heart is the aorta. The aorta
curves around and continues down the body. The curve is called the aortic arch. The
aorta gives rise to many arteries that will supply the head, thoracic and abdominal
organs with valuable blood.
The large blue blood vessel coming from the right side of the heart is the pulmonary
trunk that branches off into the pulmonary arteries. These blood vessels take the blood
from the heart to the lungs to pick up oxygen.
ARTERIOVENOUS CAST OF THE KIDNEYS
The kidneys are responsible for purifying the blood. The large red blood vessel going
into the kidneys is the renal artery. It is an artery that directly branches off of the aorta.
After the blood is filtered by the tiny nephrons within the kidneys, the blood is returned
to the circulating blood supply by the renal vein, the large blue blood vessel.
ARTERIOVENOUS CAST OF THE LIVER
This cast shows the arteries and veins within the liver.
ARTERIOVENOUS CAST OF UPPER AND LOWER LIMB AND WOMAN’S PELVIS
These exhibits show the extensive blood vessels that supply the legs and pelvis with
blood. Some of the capillaries are so small and fragile they have broken off of the cast.
You can see why researchers predict there are more than 60,000 miles of blood
vessels in your body.
FETAL DEVELOPMENT
Some specimens may look smaller than the age indicated because some tissues may
have dissolved and shrunk during preservation. Ages indicated are approximate.
– 2 months à Bones and muscle begin to round out contours of body. Face and
neck develop and begin to give features a human appearance. Forehead is very
prominent, reflecting major development of brain in comparison to rest of body. Limb
buds elongate. Muscles and cartilage develop. Sex organs begin to form.
– 3 months à Sexual differentiation continues, with male sexual organs showing
more rapid development and the female remaining more neutral. Buds for all 20
temporary teeth are laid down. Vocal cords appear; digestive system shows activity.
Stomach cells begin to secrete fluid; liver pours bile into intestine. Kidneys begin
functioning, with urine gradually seeping into amniotic fluid. Other waste products are
passed through placenta into mother's blood. Bones and muscles continue
development and by end of third month, spontaneous movements of arms, legs,
shoulders and fingers are possible
– 4 months à Growth of lower parts of body accelerate, so that head size decreases
from one-half to one-fourth of body size. Back straightens, hands and feet are wellformed. Skin appears dark red, as coursing blood shows through the thin layer of skin,
which is wrinkled due to the absence of underlying fat. Finger closure is possible.
Reflexes become more active as muscular maturation continues. Fetus begins to stir,
thrusting out arms and legs in movements readily perceived by the mother.
– 5 months à Skin structures begin to attain final form. Sweat and sebaceous glands
are formed and function. Skin derivatives also appear – hair, and nails on fingers and
toes. Fetus is lean and wrinkled, about one foot long and weighing about one pound.
– 6 months à Eyelids, which have been fused shut, open and eyes are completely
formed. Taste buds appear on tongue and in mouth and are, in fact, more abundant
than in the infant or adult.
– 7 months à Organism is capable of independent life from this time on. Cerebral
hemispheres cover almost the entire brain. A seven-month-old fetus can emit a variety
of specialized responses.
– 8 months à During the eighth and ninth months, finishing touches are being put
on the various organs and functional capacities. Fat is formed rapidly over the entire
body, smoothing out the wrinkled skin and rounding out body contours. Fetus is active
and can change positions within the crowded uterus. Fetal organs step up activity and
heart rate becomes quite rapid. Digestive organs continue to expel more waste
products, leading to the formation of a fetal stool, called the meconium, which is
expelled shortly after birth.
– Final display is of a fetus early in the ninth month.
MUSCLE MAN
You can tell that the Muscle Man spent a lot of time in the gym by the large sketetal
muscles. Prominent muscles seen on the Muscle Man include:
· Sternocleidomastoid, which flexes the head forward
· Trapezeius, which helps to shrug shoulders
· Pectoralis major, which rotates arms and brings them inward; major
muscle in climbing, throwing and pushing
· Deltoid, which moves arms away from body; active during rhythmic arm
swinging movements during walking
· Triceps, which extends arm; increases angle at elbow
· Biceps, which flexes arm; decreases angle at elbow
· Tensor, fasciae which moves leg away from body
· Rectus femoris, vastus lateralis and vastus medialis, all of which compose
part of the quadriceps ,which extend the knee
· Tibialis anterior, which pulls feet upward
· Gastrocnemius, which points feet downward
· Gluteus maximus, which extends the thigh; active during climbing stairs
and running
Muscle Man needs lots of energy to flex his muscles, so he must consume enough
calories to maintain the energy demands the muscles need to contract. Muscle Man’s
digestive system ensures that the food he consumes gets broken down into tiny
molecules that the muscle cells can use for energy. By the time his chewed food
reaches the stomach, carbohydrates (such as starches in a baked potato or cereal)
have already begun digestion. In the very acidic stomach, some proteins are digested
and a little water is absorbed (along with alcohol and some medications). Next, the
liquefied food will travel to the small intestine where carbohydrates, fats and proteins will
be digested into their smallest particles. Before that can happen, the pancreas secretes
a substance called bicarbonate, also known as baking soda, into the small intestine to
neutralize the acidic food coming from the stomach. The pancreas also secretes the
hormones insulin and glucagons that help control blood sugar.
Once the food is digested, the nutrients are absorbed into the blood stream and travel to
the liver. The liver contains many enzymes that modify the nutrients before they travel to
the cells where they are absorbed. The food waste not absorbed by the small intestines
travels to the large intestine, also known as the colon. See the appendix in the Muscle
Man, where the small intestine meets the large intestine. For a while, doctors and
scientists believed the appendix had no function for modern man. But after examining
the tissue of the appendix, they now believe it may have a disease fighting role in the
immune system.
As the waste moves through the large intestine, much of the water is removed. E. coli
bacteria naturally found in the colon helps break down unutilized food, produces vitamin
K essential for blood clotting, represses the growth of harmful microorganisms, and
trains the immune system to respond only to disease causing organisms. After moving
through the intestine, the waste exits the body via the anus (see back of Muscle Man).
Fact: Your stomach produces mucus constantly to help protect your stomach from
stomach acid. Stomach acid (pH range of 1.0 – 3.0) can have the same acidity as
battery acid (pH 1). If your stomach didn’t produce mucus, the stomach acid would
erode your stomach and create ulcers.
Fact: The small intestine is named for its diameter compared to the large intestine. The
small intestine is extremely long, stretching to 22 feet in an adult.
Fact: In the United States, the average person consumes more than 50 tons of food
and drinks more than 13,000 gallons of liquid.
Fact: The cell lining of your digestive system is shed every 3 days.
Fact: An adult human body produces almost half a gallon of saliva a day.
MEDICAL APPLICATIONS
Approximately 4% of Americans suffer from gastro-esophagal reflux disease (GERD)
which is commonly known as acid reflux disease. Most people describe their symptoms
as having heartburn, even though the disease doesn’t have anything to do with the
heart. GERD is usually caused by abnormal relaxation or weakening of the cardiac
sphincter, the valve between the esophagus and the stomach. The purpose of the
sphincter is to keep the acidic food in the stomach. The weakening of the valve allows
the acidic food to go up the esophagus, creating the “burn.” Sometimes, the acids are
aspirated into the respiratory system, causing hoarseness, coughing and asthma. If
untreated, the prolonged exposure to acid can cause ulcers and precancerous cells in
the esophagus. Individuals with GERD are treated with antacids and drugs that
decrease the secretion of stomach acids. In extreme cases, surgery is used to
reconstruct the valve of the lower esophagus.
It is estimated that 20 million people in the United States have gallstones. Gallstones
are formed in the gall bladder as a result of crystallization of cholesterol and bile salts
from the bile. Bile is produced in the liver from cholesterol and is stored in the gall
bladder. Bile is secreted into the small intestines to help digest fats. Gallstones usually
range in size from a grain of sand to 2 inches wide.
Often, there are no symptoms of gallstones. The gallstones lie quietly within the gall
bladder and are usually found by chance. If a gallstone is obstructing the gall bladder,
there will be severe pain in the upper right side of the abdomen. The pain will come and
go in waves as strong muscular contractions. Strong muscular contractions occur
because the body is trying to get rid of the obstruction. Other symptoms of gallstones
are mild pain under the right ribs. This pain occurs after eating fatty foods because fat in
the diet provokes a reflex contraction of the gall bladder. Sometimes gallstones may
pass out of the body spontaneously. If the gallstones are causing pain, they can be
removed by surgical procedures. If gallstones continue to develop, the gall bladder can
be removed. Bile will flow directly into the small intestines and not interfere with normal
digestion.
CORONAL FACE SLICES
The head has been cut into equal slices to show various structures. In the first slice,
showing the back of the head, you can see where the cerebrum and cerebellum sits in
the cranium. Notice the space between the skull and the brain. On the fourth slice, the
spinal cord is visible. In the seventh through tenth slices, the nasal cavities are seen.
The nasal cavity has many folds that increase the surface area to more efficiently warm
the air you breathe in.
The brownish retina is seen on the tenth slice. The retina contains the nerve cells
called rods and cones that send information to the brain about light and color. Also in
the tenth slice, sinuses above the nasal cavity are visible.
ACTRESS
Actresses actively memorize lines and act out scenes. Many chemical reactions are
taking place within her organs to allow her to think, memorize, speak and do all the
actions to portray a scene. Metabolism, the sum of all the chemical reactions that take
place in your body, makes useful molecules you need to function and produces waste
substances as well. It is the role of your excretory system, also called the urinary
system, to get rid of these excess waste molecules. The key organs of waste removal
are the kidneys, which are found toward the back of the body cavity (seen on the
Actress on the right side under the diaphragm).
About 20% to 25% of your blood is flowing through your kidneys at any given moment.
Each kidney contains approximately a million tiny filtering units called nephrons. These
nephrons help regulate the water balance in the body and filter out the waste material in
the blood. On a hot stage, the actress would need to drink more because she loses
water from sweating. Her urine, the liquid waste her kidneys produce, would be a
darker yellow if she was not staying hydrated. The urine flows from each kidney to a
tube called the ureter. Each ureter then drains the urine into the storage tank called the
urinary bladder, which is visible in the Actress in the lower abdominal cavity. The
urinary bladder has the ability to stretch, holding two tablespoons to two cups of urine.
When it stretches to a certain point, a nerve sends a signal to your brain, triggering the
need to urinate. Urine leaves the body via the urethra. Although it doesn’t seem like
the bladder and kidneys have glamorous functions, they are essential in maintaining
water and electrolyte balance (calcium, potassium and sodium), as well as getting rid of
dangerous waste. Think of the kidney’s role in the body as a water purification plant
that keeps a town’s water safe to drink. This is exactly what the kidneys do to make
your blood clean with the proper water and chemical balance.
Reproductive organs also are visible within the Actress. Fertilization of the egg takes
place in the fallopian tube, which is also known as the oviduct. The growing embryo
travels from the fallopian tube to the uterus where it implants into the uterine wall. After
approximately 280 days, the mother gives birth via the vagina (birth canal). The uterus
and fallopian tubes are shown in the Actress. The female body also is equipped to feed
the child after birth. The mammary glands become active before birth to get ready to
produce milk. Key hormones stimulate the mammary glands to produce milk after the
baby is delivered. The green ducts you see on one of the breasts is a duct that will
deliver milk from the mammary glands to the nipple.
Fact: The world's heaviest kidney stone weighed 12.5 ounces and measured 4.66
inches at its widest point.
Fact: It was once thought that females were born with all the eggs they will ever have.
Recent studies on female mice show that mice ovaries contain stem cells that can
become eggs. Scientists are now researching to see if the same is true for humans.
Fact: The largest cell in the human body is the female ovum, or egg cell. It is about
1/180 inch in diameter.
Fact: After fertilization, every human spends about half an hour as a single cell. Adults
are comprised of approximately 50 to 100 trillion cells.
MEDICAL APPLICATION
Kidney stones are created when certain substances in urine crystallize, including
calcium and uric acid. These substances form crystals, which can join together to form a
stone. Kidney stones usually form within the kidney where urine collects before flowing
into the ureter, which is the tube that leads to the bladder. Small kidney stones are able
to pass out of the body in the urine and may go completely unnoticed by you. But larger
stones irritate and stretch the ureter as they move toward the bladder, blocking the flow
of urine and causing excruciating pain. Certain people are frequent "stone formers." A
person who has one stone has a 50% chance of developing another stone over 10
years, with about a 15% risk in the first year or so.
Bladder infections, also called urinary tract infections (UTI), are a common infection of
the urinary system. E. coli bacteria, naturally found in the large intestine, sometimes
enters the urethra and travels to the urinary bladder, causing 85% of bladder infections.
Females, with a shorter urethra, get more bladder infections than males. Men also
usually urinate before the bacteria has time to attach to the urinary bladder and cause
inflammation.
Endometriosis is a common health problem in women. It gets its name from the word
endometrium, the tissue that lines the uterus, or womb. In the womb, tissue that looks
and acts like the lining of the uterus grows outside of the uterus. This "misplaced"
tissue can cause pain and/or infertility. Pain is one of the most common symptoms of
endometriosis. Usually the pain is in the abdomen, lower back and pelvis. There is no
cure for endometriosis. Treatments include pain medication, hormone treatment and
surgery in severe cases.
SLICE OF LIFE
This display is a unique look into the human body from a different perspective.
Normally sectional views of the body are created by medical equipment called a CAT
scan or MRI.
CAT scanning, also called CT scanning, is a noninvasive, painless medical test that
helps physicians diagnose and treat medical conditions. CAT imaging uses special Xray equipment to produce multiple images or pictures of the inside of the body and a
computer to join them together in cross-sectional views of the area being studied. The
images can then be examined on a computer monitor or printed.
CAT scans of internal organs, bone, soft tissue and blood vessels provide greater clarity
than conventional X-ray exams. Using specialized equipment and expertise to create
and interpret CAT scans of the body, radiologists can more easily diagnose problems
such as cancers, cardiovascular disease, infectious disease, trauma and muscle and
skeletal disorders.
MRI scans can also give doctors images of internal tissues and organs without
performing surgery. The MRI (magnetic resonance imaging) scan uses magnetic and
radio waves, meaning that there is no exposure to X-rays or other damaging forms of
radiation.
The patient lies inside a large, cylinder-shaped magnet. Radio waves 10,000 to 30,000
times stronger than the magnetic field of the earth are then sent through the body. This
affects the body's atoms, forcing the nuclei into a different position. As they move back
into place they send out radio waves of their own. The scanner picks up these signals
and a computer turns them into a picture. These pictures are based on the location and
strength of the incoming signals.
With an MRI scan it is possible to take pictures from almost every angle, whereas a
CAT scan only shows pictures horizontally. There is no ionizing radiation (X-rays)
involved in producing an MRI scan. MRI scans are generally more detailed, too. The
difference between normal and abnormal tissue is often clearer on the MRI scan than
on the CAT scan.
WANDERER
The Wanderer needs to coordinate his every move to wander this Earth. There are
different types of joints which account for all of the different movements of the human
body. Joints are the weakest parts of the skeleton, but their structure enables them to
resist crushing, tearing and twisting that would put them out of alignment. Muscles help
move bones at joints. If the joint is subjected to extreme force, damage can result with
dislocation, strain, sprain, or torn ligaments.
Connective tissue called ligaments hold bones together at joints. Ligaments, which
attach muscle to bone, add stability to the joint. Can you find ligaments on the
Wanderer? These tough bands are hard to see because there is other connective
tissue that surrounds the joint on top of the ligaments.
Joints that allow leg movement include the ball and socket joint, such as the one that
joins the hip bone with the femur, the large thigh bone. The joint is appropriately named
because of the head of the femur fits into the socket of the pelvic, or hip bone.
Your shoulder joint, connecting the humerus (upper arm bone) to the clavicle
(collarbone) and scapula (shoulder blade), also is a ball and socket joint. This type of
joint allows for a great range of motion. Notice the deltoid muscle has been dissected to
see the joint. The pectoralis major has also been removed to see the pectoralis minor
underneath.
Another important joint the Wanderer uses to wander the
Earth would be the hinge joint at the knee. The knee is much
like a hinge of a door, only being able to extend so far. If hyperextension takes place
(extended too far), there can be extensive damage to the supporting connective tissues
that stabilize the knee joint. The elbow joint connecting the humerus to the ulna and
radius is also a hinge joint, like the knee.
The Wanderer’s facial expressions are made by muscles attached to skin. You can
also see the large masseter muscle that he needs to chew food. The orbicularis oris that
surrounds the mouth allows the lips to purse for kissing or whistling. The orbicularis
oculi around the eye closes the eye for blinking or squinting.
Fact: On average, a person takes about 8,000 to 10,000 steps a day. In a lifetime, a
person may walk approximately 115,000 miles. That distance is equivalent to walking
five times around the equator.
Fact: The knee is the most easily injured joint. The kneecap, also called the patella,
does not develop in children until they are two to six years of age.
MEDICAL APPLICATION
Arthritis is the most common cause of disability in the United States, limiting the
activities of nearly 19 million adults. Arthritis is inflammation of one or more joints,
which results in pain, swelling, stiffness and limited movement.
There are over 100 different types of arthritis. Osteoarthritis is the most common type
and is more likely to occur as you age. You may feel it in any of your joints, but most
commonly in your hips, knees or fingers. Risk factors for osteoarthritis include:
· Being overweight
· Previously injuring the affected joint
· Using the affected joint in a repetitive action that puts stress on the joint (baseball
players, ballet dancers and construction workers are all at risk)
Another common type of arthritis is rheumatoid arthritis (RA). RA is a long-term
disease that causes inflammation of the joints, surrounding tissues and sometimes
other organs. RA is considered an autoimmune disease. The body's immune system
normally fights off foreign substances, like viruses and bacteria. But in an autoimmune
disease, the immune system confuses healthy tissue for foreign substances. As a
result, the body attacks itself. In this case, the immune system attacks the joints which
cause debilitating pain and swelling. With time, the joints become disfigured.
REPRODUCTIVE SYSTEM ORGANS
The reproductive organ display shows the ureters, one from each kidney, which carry
urine to the urinary bladder.
On the female specimen, one of the ovaries, the organ that produces the eggs, has a
tumor or cyst. If a healthy egg is released from the ovary, it travels into the fallopian
tube. If fertilized by sperm, it travels to the uterus and imbeds in the uterine wall.
On the male specimen, the renal arteries and veins are seen entering and exiting the
kidneys. The testes produce numerous sperm, the male sex cell. The sperm travels
into the man’s body through the vas deferens. As the sperm travels through the tube,
glands such as the seminal vesicles and prostate secrete seminal fluid. Both semen
and urine exit the urethra through the penis. The urethra for males serves both a
reproductive and excretory function. In females, however, the urethra has only an
excretory function.
KIDNEY AND URINARY BLADDER
Kidney cysts, pockets of air or fluid, can form on or in the kidneys. The discoloration on
areas of this kidney suggests that the cysts may be internal. The dissected kidney
shows the cavity, called the renal pelvis, in which urine collects before being transported
to the kidney by the ureter.
On top of the male urinary bladder is the swollen structure known as the prostate. In a
male’s body, the prostate sits below the urinary bladder. If the prostate becomes
enlarged, it presses on the urinary bladder, causing the man to have to urinate more
often.
THE DISCUS THROWER
To throw the discus, one has to use many different muscle groups. The most obvious
are the skeletal muscles, muscles that attach to bones to move them, such as those in
the arm and shoulder. The large shoulder muscle is the deltoid and the front upper arm
muscle is the biceps. The back upper arm muscle is the triceps, opposite the bicep. On
the front of the chest are the large pectoralis major muscles that help bring the arm
forward during the discus throw. Other muscles involved in throwing include the serratus
anterior on the upper side of the chest, under the arms, which is used for pushing and
punching. It has been called the “boxer’s muscle.” The large latissimus dorsi on the
side of the back rotates the arm at the shoulder. It also plays an important role in
bringing the arm down for a power stroke, as in hammering, swimming and rowing.
A lot of the power of the discus throw comes from the front leg muscles, called the
quadriceps (rectus femoris is part of the quadriceps), and the large buttock muscle,
called the gluteus maximus.
If you look carefully at the skeletal muscle, you can see the muscle fibers running in the
same parallel direction. When muscle fibers contract they pull on a bone. A nerve
stimulates a muscle, causing the protein molecules of the muscle fiber to slide over one
another, which then shortens the muscle as it pulls on a bone. Muscles are attached to
bones by tough tendons. You can see the Achilles tendon, also called the calcaneal
tendon that connects the gastrocnemius (calf muscle) to the calcaneus (heel bone).
Fact: It takes 17 muscles to smile and 43 muscles to frown.
Fact: The gluteus maximus (buttock muscle) is the largest muscle of the human body.
Fact: Muscles can only pull on a bone; they never push. To get a joint to move in the
opposite direction, another muscle has to pull on it.
MEDICAL APPLICATION
If you have ever experienced a charley horse or muscle cramp you know how painful
it can be. Muscle cramps occur when muscles involuntarily contract and cannot relax.
Often a muscle that is cramping feels harder than normal to the touch or may even
show visible signs of twitching. Most cramps resolve spontaneously within a few
seconds. The cause of muscle cramps is not completely known. Insufficient stretching
before exercise, exercising in the heat and muscle fatigue may all play a role in their
development. Imbalances in the levels of electrolytes such as sodium, potassium,
chloride and calcium in the blood can also lead to muscle cramps. To prevent cramps,
a person should stretch and warm up properly before exercise and make sure to stay
hydrated. Electrolyte sports beverages can help to replenish electrolytes during and
after exercise. If a cramp does occur, hold the cramped muscle in a stretched position
until the cramp resolves.
Restless Leg Syndrome (RLS) is characterized by an irresistible urge to move the
body due to uncomfortable sensations. RLS is actually a neurological disorder of the
brain that affects limbs by sending signals to nerves and muscles which causes the
irritating sensations. According to the RLS Foundation, 10% of American’s are living
with Restless Leg Syndrome. The legs are the most common parts of the body
affected, but the arms can be targeted too. Restless Leg Syndrome causes a sensation
of burning, itching, or tingling. These sensations are temporarily relieved by movement
of the body part affected. Because RLS most often occurs in the evening, it can
severely disrupt sleep and reduce quality of life. There is no cure for RLS, but there are
medications that can help alleviate the sensation. Changing certain lifestyle behaviors
can help reduce symptoms such as eliminating caffeine and alcohol, getting regular
exercise, obtaining enough iron in your diet, and implementing good sleep habits.
SOCCER PLAYER
Some athletic activities can be rough, and soccer is no exception. The Soccer Player is
equipped with a protective rib cage that helps protect vital organs such as the heart and
lungs. The rib cage is adapted to take a blow, but also is flexible enough to allow the
thoracic cavity to expand with every breath. Sometimes, if the trauma is severe
enough, a rib may break, which can puncture the sac (pleural sac) around the lungs,
making it impossible for the lungs to push air in and out.
Sometimes the Soccer Player may use other body parts to pass the ball to his
teammates, such as his head. The brain is protected from injury by the skull bones that
comprise the cranium. The cranium surrounds the delicate nervous system the Soccer
Player needs to see the field and ball, hear his coach and coordinate his movements to
make a goal. Just think of the brain damage we all would have if we did not have the
protective bones surrounding our brain.
The thoracic cavity is separated from the abdominal cavity by the muscular diaphragm
as seen on the Soccer Player. Notice that the abdominal cavity is not as protected as
the cavity housing the heart and lungs. The spleen, visible in the abdominal cavity, is
very susceptible to injury because there is little protection. The spleen helps filter the
blood of unwanted materials such as bacteria and dead blood cells and is a reservoir for
red blood cells. Because of the abundant blood supply, a lacerated (torn) spleen may
cause serious internal bleeding (hemorrhage).
Also seen in the abdominal cavity are the intestines, which are covered with a large
membrane called the greater omentum. The omentum is a major storage of belly fat
and tends to store more fat as we age and our metabolism slows. One of the functions
of the greater omentum is to serve as a shock absorber for abdominal blows. The
omentum is a great example of how tissue, other than bone, can help to protect organs.
You can see the small intestines in the middle of the abdomen and the large intestine
(colon) toward the outside.
ABDOMINAL CAVITY
Fact: At birth, the skull bones of infants have not fused. The spaces between the skull
bones are commonly called soft spots or fontanels. If you softly touch one of a baby’s
fontanels, if feels like gushing water, which is actually the baby’s pulse. When you were
born, you had approximately 300 bones in your body. As an adult, you have 206,
because many of the original bones have fused together.
Fact: Between fertilization and birth, an infant’s weight increases 5 million times.
Fact: According to the Journal of American Academy of Neurology, middle-aged people
with a large belly (excessive belly fat) are at a 90% greater risk of developing dementia
later in life.
MEDICAL APPLICATION
The Soccer Player would have a hard time playing if he had Metabolic Syndrome.
According to the American Heart Association, 50 million Americans - one in six – have
it. Metabolic Syndrome is not a disease, but a group of risk factors including high blood
pressure, high blood sugar, unhealthy cholesterol levels and abdominal fat that
develops in the omentum. All of these risk factors raise your odds of serious health
problems, including diabetes and blood vessel or heart disease. Specifically, metabolic
syndrome can lead to arteriosclerosis, or "hardening of the arteries." This is when fats,
cholesterol and other substances stick to the sides of the arteries. The arteries then
become clogged and brittle. Blood clots form when the arterial walls are damaged. If a
blood clot forms, it can cause a heart attack or stroke. Here are some sobering statistics
from the American Heart Association:
· Heart disease is the leading cause of death in the U.S.
· This year 1.2 million Americans will have a heart attack -- 479,000 will die.
· This year 700,000 Americans will have a stroke -- 158,000 will die.
· 65% of all people with diabetes die from heart or blood vessel disease.
By changing your lifestyle through regular exercise and a healthy diet, you can lower
your risk for Metabolic Syndrome and the diseases it can lead to.
MAN ON A MISSION
The Man on a Mission must have a constant flow of blood to his muscles to keep on the
move. The cardiovascular system consists of the muscular hear that serves as the
pump and blood vessels that carry blood to the tissues and back. Your cardiovascular
system is a closed circuit that continually pumps blood back to the heart, then to the
lungs to pick up oxygen and leave off carbon dioxide. The blood then goes from the
lungs back to the heart, which then pumps the oxygenated blood to the rest of the body.
The body cells use the oxygen, nutrients and electrolytes that the blood carries.
Hormones, chemical messengers of the human body that have been secreted by
endocrine glands such as the thyroid, are also transported in blood. The hormones the
thyroid produces influence many target cells of your body to increase the rate in which it
uses oxygen to transform nutrients into energy the cells can use.
You can see the heart in the middle of the Man on a Mission’s chest with two large
blood vessels attached to the top. Deoxygenated blood (blood with lower oxygen
levels) drains into the right side of the heart through the superior vena cava and inferior
vena cava. These large veins are not visible on the Man on a Mission because they
enter the heart on the back side of the heart. The big blue blood vessel is called the
pulmonary artery which branches off and takes blood from the right side of the heart to
the lungs. The pulmonary arteries are the only arteries in your body that carry
deoxygenated blood (blood with lower oxygen levels). After the oxygen has entered the
blood in the lungs, the blood comes back to the left side of the heart through the
pulmonary veins. The pulmonary veins are the only veins that carry oxygenated blood.
The heart then contracts to direct the oxygen rich blood out of the left side of the heart
through the aorta, which has many arteries to direct blood to the head, arms, legs and
vital organs.
Notice the blood vessels on the heart, called coronary arteries (red) and cardiac veins
(blue). These blood vessels are essential to supplying nutrients and oxygen to the
cardiac muscle to keep the cells contracting to create the heart beat. The coronary
arteries are the vessels that can become blocked by a buildup of plaque (cholesterol
and other fatty deposits). This can lead to a heart attack because the blood cannot get
beyond the blockage. The cardiac muscle of the heart dies without nutrients and
oxygen.
On the Man on a Mission, you can easily see how the aorta branches off into numerous
blood vessels of the abdomen as well as the vessels that go down each leg. No matter
how far away the structure is from the heart, all body cells need to be supplied with the
blood to deliver the molecules needed for life.
Fact: The body of an adult contains more than 60,000 miles of blood vessels, which
would stretch around the equator two and a half times.
Fact: The sound of your heartbeat is really the sound of the valves of the heart closing
to prevent backflow of blood.
Fact: The heart beats approximately 42 million times a year and about 3 billion times in
an average lifetime.
Fact: The heart produces so much pressure during contraction that it can squirt blood
thirty feet.
Fact: It takes approximately one minute for the blood to make a complete circuit of the
human body.
Fact: A droplet of blood contains approximately 5 million red blood cells (to transport
oxygen to cells), 300,000 platelets (to help clot blood) and 10,000 white blood cells (to
fight infections).
MEDICAL APPLICATION
The buildup of plaque in blood vessels is called atherosclerosis. Atherosclerosis
happens in the arteries of the heart as well as the carotid arteries of the neck, which can
block blood flow. High blood pressure can increase your risk of atherosclerosis and
heart attack because the high pressure damages the inside of blood vessels making it
easier for fatty substances to be deposited over time.
Veins are different than arteries because they carry blood back to the heart instead of
away from the heart. Since many of the veins have to work against gravity to get the
blood back to the heart, veins contain valves to prevent the backflow of blood.
Varicose veins develop when the valves weaken and the blood pools in the veins.
ORATOR
The majority of the human body systems are functional even before the individual is
born. These systems, including the digestive, nervous, respiratory and excretory
systems, work continuously to maintain the well-being of the person. On the other
hand, the reproductive system does not become functional until the individual reaches
puberty. Hormones produced by endocrine glands, such as the pituitary gland in the
brain, influence the start and continuation of the maturation of the reproductive organs.
For both males and females, the reproductive system’s purpose is the same – to
produce gametes, also called sex cells, which can potentially create offspring.
As seen on the Orator, the testes are found outside the body cavity because the sperm
cells created in the testes need a 2- to 3-degree cooler temperature to survive. The
scrotum, the skin that holds the testes, contains muscles that contract to bring the
testes closer to the man’s body if needed in cold temperatures.
The sperm leaves the testes and travels through the spermatic cord, which contains
blood vessels and the vas deferens, the tube that leads up into the Orator’s body. The
sperm passes through glands that will secrete seminal fluid, including the prostate gland
and seminal vesicles. The urethra, the tube in which both semen and urine exits the
man’s body, joins with the vas deferens near the urinary bladder.
When testosterone, a male sex hormone, is produced at puberty, it influences the cells
of the larynx, also called the Adam’s Apple, to grow larger and thicker. You saw the
larynx at Display #19. The larger larynx makes the man’s voice deeper. In addition,
the facial bones begin to grow at puberty. Cavities in the sinuses, the nose and the back
of the throat grow larger as well, creating more space in the face in which to give the
voice more room to resonate, making a lower, deeper sound.
Fact: The smallest cell in the human body is the male sperm. It takes about 175,000
sperm cells to weigh as much as a single egg cell.
MEDICAL APPLICATION
For men under 50, the most common prostate problem is prostatitis. Prostatitis occurs
when the prostate is inflamed or irritated. If a man has prostatitis, he may have a
burning feeling when he urinates, or may have to urinate more often. Inflammation in
any part of the body is usually a sign that the body is fighting germs or repairing an
injury. Some kinds of prostatitis are caused by bacteria. Antibiotics usually eliminate the
symptoms of prostatitis.
The most common prostate problem is prostate enlargement. This condition is also
called benign prostatic hyperplasia (BPH). As men get older, their prostate keeps
growing. As it grows, it squeezes the urethra. Since urine travels from the bladder
through the urethra, the pressure from the enlarged prostate may affect bladder control.
Treatment involves medication and possibly surgery.
Older men are at risk for prostate cancer as well, but this disease is much less
common than prostate enlargement. It is the most common type of cancer in men in the
United States and is responsible for more male deaths than any other cancer, except
lung cancer. During a regular physical, men can be screened for prostate cancer by a
simple blood test called PSA (prostate-specific antigen). Treatment for prostate cancer
includes removal of the prostate, radiation and hormone therapy.
COMPARING HEATHY AND DISEASED HEARTS, SPLEENS,
BRAIN AND VALVES
This display shows pathology of certain organs.
conditions and processes of diseases.
Pathology is the study of the
Heart valves can have one of two malfunctions:
· Regurgitation: the valve(s) does not close completely, causing the blood to flow
backward instead of forward through the valve.
· Stenosis: the valve(s) opening becomes narrowed or valves become damaged
or scarred (stiff), inhibiting the flow of blood out of the ventricles or atria. The
heart is forced to pump blood with increased force in order to move blood
through the narrowed valve(s).
Heart valves can have both malfunctions at the same time (regurgitation and stenosis).
Also, more than one heart valve can be affected at the same time. When heart valves
fail to open and close properly, the implications for the heart can be serious, possibly
hampering the heart's ability to pump blood adequately through the body. Heart valve
problems are one cause of heart failure.
Within the display is a cancerous spleen. Cancer is a group of diseases characterized
by uncontrolled growth and spread of abnormal cells. If the spread is not controlled, it
can result in death. Cancer is caused by external factors (tobacco, chemicals, radiation
and infectious organisms) and internal factors (inherited mutations, hormones, immune
conditions and mutations that occur from metabolism). These factors may act together
or in sequence to initiate or promote carcinogenesis, the development of cancer. Ten or
more years often pass between exposure to external factors and detectable cancer.
Cancer is treated with surgery, radiation, chemotherapy and hormone therapy.
Enlarged heart is not a disease but a sign of an underlying problem. It can have many
causes, including:
§ High blood pressure
§ Heart valve disease
§ Weakness of the heart muscle due to a heart attack
§ Severe anemia
§ Thyroid disoders
§ Abnormal protein buildup in an organ
A stroke or "brain attack" occurs when a blood clot blocks an artery or a blood vessel
breaks, interrupting blood flow to an area of the brain. When either of these things
happens, brain cells begin to die and brain damage occurs. When brain cells die during
a stroke, abilities controlled by that area of the brain are lost. These abilities include
speech, movement and memory. How a stroke patient is affected depends on where
the stroke occurs in the brain and how much the brain is damaged.
COMPARING HEATHY AND DISEASED LIVERS AND LUNGS
The specimen of a smoker in this display is a great example of the damage smoking
can do to a person’s organs. The healthy lung is a little discolored due to the pigments
left in the lung during preparation of the plastinate. Compare the shape of the
smoker’s lung with the healthy lung. The World Health Organization states that one
lifestyle behavior that will help you prevent many diseases is to NOT smoke. Other
behaviors that will help you stay healthy are maintaining a healthy diet and being
physically active.
In cirrhosis of the liver, scar tissue replaces normal, healthy tissue, blocking the flow
of blood through the organ and preventing it from working as it should. Cirrhosis is the
twelfth leading cause of death by disease, killing about 26,000 people each year.
Cirrhosis of the liver can be caused by, chronic alcoholism, hepatitis viruses, blocked
bile ducts and prolonged exposure to certain drugs, environmental toxins and infections.