2. Anatomy of Respiration

Respiration - exchange of gas between an organism and its environment
Inspiration - intake of oxygen
Expiration - breathing out waste products
1!
Bony thorax (rib cage)
2!
Divided into 5 sections
vertebrae and vertebral column
numbered according to type and order from top down
ribs and their attachments to vertebral column
pectoral girdle (scapula {shoulder blades} and clavicle {collar bones})
sternum
pelvic girdle
Visceral thorax (respiratory passageway)
mouth and nose
trachea and bronchi
lungs
mediastinum [»midI´«staIn´m] - organs separating the lungs
Muscles
diaphragm
accessory muscles of inspiration
accessory muscles of expiration
muscles of postural control
3!
4!
General structure
7 cervical vertebra
spinous process (can feel when rubbing someone’s back)
C1 - Atlas - supports skull for rotation
transverse processes (on both sides)
C2 - Axis - surface for skull pivoting
attachment for muscles
corpus (body) anterior portion)
Can feel C7 when you bend head forward
vertebral foramen (spinal cord tract)
intervertebral foramen (entrance and exit for spinal nerves)
transverse foramen (located only on cervical vertebrae) pathway for vertebral
artery
superior/inferior articular facets
limits anterior/posterior movement thus protecting spinal cord
5!
transverse foramen (located only on cervical vertebrae) pathway for vertebral
6!
12 thoracic vertebrae provide basis for respiratory framework
artery
Intervertebral foramen formed by inferior and superior vertebral notches
7!
8!
5 lumbar vertebra designed especially for lifting and walking
Attaches lower extremities to vertebral column
5 sacral vertebrae are actually fused and collectively called the sacrum
Composed of:
ilium
sacrum
pubic bone
ischium
9!
10!
Attaches upper extremities to vertebral column
12 ribs with all but lowest 2 attached to sternum
Composed of:
scapula
Allows for movement up and out through chondral [»krAndrl`] or
cartilaginous connection
clavicles (attached to sternum)
1-7 known as true ribs - attach directly to sternum
8-10 - false ribs attached to sternum less directly
11-12 - floating ribs
11!
12!
Manubrium sterni - provides attachment for clavicle and 1st rib (2nd rib
Trachea - approx. 11 cm in length and 16-20 cartilage rings with open posterior
attaches to manubrium and corpus at the manubrosternal angle.
Carina trachea - splits
Corpus - directly connects to ribs 3 - 7 and indirectly to 8 - 10
Mainstem bronchi (bronchial tubes)
Xiphoid or ensiform process
connected by continuous mucous membrane lining
expands to increase oxygen intake when necessary
13!
Increasingly smaller tubes ending in the alveoli
14!
Approx. 300 million in adult lungs, 70 square meters (size of tennis court)
Each contains approximately 2000 capillaries (totaling 600 billion)
exchange between carbon dioxide in blood and oxygen-rich air in lungs
15!
16!
Accessory because not necessary for quiet breathing, but used to speak.
Origin - Attach to inferior boundary of rib cage (7-12), xiphoid process, and
vertebral column (corpus of L1-L4 and transverse of L1)
Insertion - central tendon of diaphragm
Innervation - phrenic nerve from cervical plexus [group of nerves coming
together for a single purpose] of spinal nerves C3, C4 & C5)
Function - depresses central tendon of diaphragm, enlarges vertical dimension
of thorax, distends abdomen
17!
18!
The intercostal muscles are arranged as three
layers (external layer, internal layer and an
incomplete innermost layer) between the ribs.
pleural linings of lungs and diaphragm maintain contact (like plastic wrap)
Heart located in the mediastinum (between lungs)
External intercostal muscles (11)
origin - inferior surface of ribs 1-11
insertion - upper surface of rib below
innervation - intercostal nerves ( thoracic intercostal nerves arising from
T2-T6 and the thoracoabdominal intercostal nerves from T7-T11
function - elevate ribs
19!
20!
Origin:
Inferior margin of ribs 1-11
Insertion:
superior surface of rib below
Levator costarum, longis
origin - transverse processes of T7 - T11
Innervation:
- intercostal nerves ( thoracic intercostal nerves arising from
insertion - bypass the rib below point of origin attaching to next rib
T2-T6 and the thoracoabdominal intercostal nerves from T7-T11
Function:
innervation - dorsal rami (branches) of the intercostal nerves arising from
elevate ribs 1-11
spinal nerves T2-T12
function - elevate rib cage
Levator costarum, brevis
origin - transverse processes of C7 - T11
insertion - tubercule the rib below
innervation - dorsal rami of the intercostal nerves arising from
spinal nerves T2-T12
function - elevate rib cage
Serratus posterior superior
origin - spinous processes of C7 and T1-T3
insertion - ribs 2-5
innervation - ventral intercostal portion of spinal nerves T1-T4 or T5
Function - elevate ribs 2-5
21!
22!
Sternocleidomastoid (sternomastoid)
origin - mastoid process of temporal bone
insertion - superior manubrium sterni; clavicle
innervation - XI Accessory, spinal branch arising from spinal cord in
regions of C2 - C4 or C5
function - elevate sternum and, by association, rib cage
Scalenus anterior
origin - transverse process of C3 - C6
insertion - superior surface of rib 1
innervation - C4-C6
function - elevate rib 1
Scalenus medius
origin - transverse process of C2 - C7
insertion - superior surface of rib 1
innervation - cervical plexus derived from C3 and C4 and spinal nerves C5-C8
function - elevate rib 1
Scalenus posterior
origin - transverse process of C5 - C7
insertion - second rib
innervation - spinal nerves C5-C8
function - elevate rib 2
23!
24!
Origin - spinous processes of C2 - T12
Insertion - acromion of scapula and superior surface of clavicle
Innervation - XI Accessory, spinal branch arising from spinal cord in
regions of C2 - C4 or C5
Function - elongates neck and controls head (supports for inhalation)
25!
26!
27!
28!
Pectoralis Major
origin - sternal head: length of sternum at costal cartilages; clavicular head:
anterior clavicle
insertion - greater tubercle of humerus
innervation - superior branch of the brachial plexus (spinal nerves C4-C7 & T1)
function - elevate sternum increasing dimension of rib cage
Pectoralis Minor
origin - anterior surface of ribs 2 - 5 near chondral border
insertion - coracoid process of scapula
innervation - superior branch of the brachial plexus (spinal nerves C4-C7 & T1)
function - increasing transverse dimension of rib cage
Serratus anterior
Subclavius
origin - Ribs 1 - 9, lateral surfacs of thorax
origin - inferior surface of clavicle
insertion - inner vertebral border of scapula
insertion - superior surface of rib 1 at chondral margin
innervation - brachial plexus, long thoracic nerve from C5 - C7
innervation - brachial plexus, lateral branch, from fifth and sixth spinal
function - elevate ribs 1 - 9/stabilize and rotate scapula
nerves
function - elevate rib 1
29!
Levator Scapulae
30!
Rhomboideus major
origin - transverse processes of C1 -4
origin - spinous processes of T2 - 5
insertion - medial border of scapula
insertion - scapula
innervation - cervical plexus
innervation - brachial plexus
function - neck support, elevates scapula
function - stabilize shoulder girdle
Rhomboideus minor
origin - spinous processes of C7 and T1
insertion - medial border of scapula
innervation - brachial plexus
function - stabilize shoulder girdle
31!
32!
Internal intercostals (Interosseous portion) (chondral portion also active in
forced inspiration)
origin - inferior surface of ribs 1-11 (??)
insertion - superior margin of rib below (??)
innervation - intercostal nerves and thoracoabdominal intercostal nerves
function – fixes ribs allowing other muscles to act (depresses ribs 1-11)
33!
34!
35!
36!
innermost layer -- (the innermost layer is split into three
differently named muscle groups. The transversus thoracis,
innermost intercostal and subcostal muscles make up the
deepest layer of muscles from anterior to posterior,
respectively.)
transversus thoracic (anterior),
innermost (lateral) and
subcostal (posterior)
Innermost intercostal
origin - superior surface of ribs 1-11
insertion - inferior margin of rib above
innervation - intercostal nerves and thoracoabdominal intercostal nerves
function - depresses ribs 1-11
Transversus thoracis (triangularis sterni)
origin - inner thoracic lateral margin of sternum
insertion - superior surface (inner chondral surface) of rib below
innervation - Thoracic intercostal nerves, thoracoabdominal intercostal
nerves and subcostal nerves
function - depresses rib cage
Subcostal (Part of Innermost Intercostals)
origin - inner surface of the ribs
insertion - inner surface of second and third rib below
innervation - intercostal nerves
function - depresses thorax resulting in lowered ribs
Serratus posterior inferior
origin - spinous processes of T11, 12, L1-3
insertion - lower margin of ribs 7-12
innervation - lower thoracic spinal nerves
function - depresses lower ribs
37!
Transverse abdominis
38!
External oblique abdominis
origin - posterior abdominal wall at the vertebral column, iliac crest, lower
origin - outer surface and border of ribs 5-12
borders of ribs 6-12, and the thoracolumbar fascia
insertion - iliac crest, inguinal ligament, and abdominal aponeurosis lateral
insertion - xiphoid process, linea alba, crest of pubis
to rectus abdominis
innervation - lower intercostals nerves (T7-12 & L1)
innervation - intercostal nerves (T7-11 & L1)
function - supports and compresses abdomen
function - depresses thorax, supports and compresses viscera
The deepest layer of abdominal muscles, the transversus abdominis, is not
involved in movements of the trunk (Rasch & Burke, 1978). Instead, this
respiratory muscle plays an important function in forceful expiration of air
from the lungs; as well as compression of the internal organs.
The external oblique muscles are the outermost fibers of the trunk, and are
located on each side of the rectus abdominis. Their upper and lateral
attachments are to the lower eight ribs by tendinous insertions that interdigitate
(interlock like the fingers of folded hands) with the serratus anterior muscle on
the side of the rib cage. The lower and middle attachments of the external
obliques are to the anterior crest of the pelvis (iliac crest) and the aponeurosis
of the linea alba from the ribs to the crest of the pubis. The external oblique
muscle actually becomes the inguinal ligament #(Hay & Reid, 1982)#. The
fibers of this muscle run diagonally, forming a “V” shape, similar to putting
your hands into your coat pocket.
39!
40!
Internal oblique abdominis
Rectus abdominis
origin - inguinal ligament and iliac crest
origin - originates as four or five segments at pubis inferiorly
insertion - cartilaginous portion of lower ribs of the abdominal aponeurosis
insertion - xiphoid process of sternum and cartilage of ribs 5-7, lower ribs
(extended flat sheath-like attachment) lateral to the rectus abdominis
innervation - lower intercostals (T7-12)
innervation - lower intercostals (T7-12 & L1)
function - supports and compresses viscera (flexs vertebral column)
function - rotates trunk, flexes trunk, compresses abdomen
Quadratus lumborum
origin - iliac crest
Beneath the external oblique muscles, running at approximately right angles to
them, are the internal oblique muscles which form an inverted “V” shape.
Their upper and medial attachments are to the cartilages of the lower three ribs
and the aponeurosis of the linea alba. Their lower and lateral attachments are to
the inguinal ligament, the crest of the pelvis, and the fascia (connective tissue)
of the lower back (erector spinae). At the lower end the internal oblique muscle
fibers run almost horizontally. Both the external and internal oblique muscles
are involved in flexing the rib cage and the pelvic bones together, sideward
bending (lateral flexing) of the trunk, and rotating the trunk. The external
obliques are referred to as “opposite side” rotators. Due to the muscle fiber
arrangement, when you rotate to the left, the external oblique fibers on your
right side facilitate the movement. Conversely, if you rotate to your right, the
left external oblique fibers help with the movement. On the other hand, the
internal oblique muscles are “same side” rotators. Thus, if you rotate to the left,
the left internal oblique muscles facilitate the movement. When you rotate to
the right, the right internal oblique muscles help cause the motion.
Due to the fact that the lower fibers of the internal oblique muscles run
horizontally, they also are strong trunk rotators (Luttgens & Wells, 1992)#.
Although most people think of the oblique muscles as being only frontal
muscles, it is important to note that their fan-like fibers extend all the way
insertion - transverse processes of lower lumbar vertebrae and inferior
border of rib 12
innervation - thoracic nerve T12 and L1-4 lumbar nerves
function - bilateral contraction fixes abdominal wall in support of
abdominal compression
41!
The mid-section muscles consist of the rectus abdominis
and the internal and external obliques. The rectus
abdominis is a long, flat band of muscle fibers extending
vertically between the pubis and the cartilages of the fifth,
sixth, and seventh ribs on the front part of your trunk. Its
right and left halves are separated in the middle by a strong
tendinou sheath known as the linea alba (which means
white line). There are three horizontal tendinous creases
that give the muscle that “washboard” appearance on some
42!
Latissimus dorsi
origin - lumbar, sacral, and lower thoracic vertebrae
insertion - humerus
innervation - brachial plexus
function - stabilizes posterior abdominal wall for expiration.
43!
44!
45!