Lecture 16 Urinary/Endocrine Systems

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Lecture 16 Urinary/Endocrine Systems
PREPARE FOR THIS WEEK IN LAB:
IMMUNOHISTOCHEMISTRY
•! CHOOSE ANTIBODIES
LAB PROJECT WRITTEN REPORT
Write your own paper describing organ histological analysis.
(staining results of frozen and paraffin-embedded sections)
The report: - typed, double-spaced, and in your own words.
- include labeled images with figure
•!Double-labeling, 2 primary antibodies
•!Indirect, 2 secondary antibodies (red, green)
•!PLUS! DAPI – nuclear stain (blue)
In several paragraphs, address the following:
•!What organ did you stain?
•!Why did you choose this organ for study?
•!What are the organ’s distinguishing histological features?
•!Are these features evident in your images?
•! READ IMMUNOHISTOCHEMISTRY PROTOCOL
See webpage
•!What is the function of the organ?
•!Relate the distinguishing histological features to its function.
•!What antibodies and probes did you use?
•!What structures did you predict would be stained?
•!What structures actually stained?
•!Discuss your results including problems or artifactual staining.
•!Discuss 1 disease condition of your organ & the histology of it.
SECTIONING AND STAINING ARTIFACTS
Chatter
Knife Marks
Wrinkles/Crushing
Over/Under/Uneven staining
High Background/Space junk
Nonspecific stain
LAB PROJECT WRITTEN REPORT
***REPORTS DUE AT THE FINAL EXAM***
Rubric for Scoring (20 Points)
- clarity and appropriate use of histological terms (3)
Crushing
Chatter
Knife
Marks
- accurate, clear and neat labeling of images,
appropriate figure legends (8 points)
- discussion of choice of markers, anticipated staining,
interpretation of actual staining pattern, and discussion of
problems or artifactual staining (3)
- discussion of disease and its predicted effects on the
organ histology (4)
Knife Marks
Understained
1
FINAL EXAM
1:30 PM FRIDAY DECEMBER 17th
Morrill 222
Loop Henle
Descending & Ascending limbs
thin and thick segments
Vary in epithelium
descending thick --> simple cuboidal
descending thin --> simple squamous
ascending thin --> simple squamous
ascending thick --> simple cuboidal
Vary in permeability and molecular composition
descending thin --> highly permeable to water
ascending thin --> impermeable to water
Countercurrent multiplier
Countercurrent multiplier:
Flow of blood and filtrate are in opposite directions
Distal convoluted tubule
cuboidal, extensive basal and lateral invaginations
Na reabsorption
Ascending limb:
K secretion
Impermeable to water
Outward movement of Na
=> increased osmotic pressure
in interstitial fluid
Regulated by
ALDOSTERONE
Collecting Tubule:
Descending limb:
Clear cell boundaries,
large diameter, more
nuclei than proximal
Permeable to water
!!water leaves filtrate
Thin Tubule:
Simple squamous
Water enters Vasa recta
www.nature.com/.../v21/n1/full/ng0199_67.html
2
Collecting ducts
Permeability to water controlled by antidiuretic hormone
(ADH), secreted by pituitary gland
=> insertion of aquaporin channels in apical membrane
No ADH, water excretion
Collecting Ducts
Clear cell boundaries, large diameter, more nuclei than proximal
ADH, water reabsorption
www.uic.edu/.../bios100/lecturesf04am/lect21.htm
Diabetes Insipidus
Inability of kidneys to conserve water
results in frequent urination and pronounced thirst
What are the possible causes?
Renal Pelvis ----> Ureter -----> Bladder
Mucosa: Transitional epithelium
- lamina propria
Muscularis: Smooth muscle
Longitudinal inner layer
Circular outer layer
Adventitia
3
25.
URETER
BLADDER
URETER
Urethra
Epithelium:
Female: Transitional----> Stratified Squamous
Male: Transitional----> Stratified or
Pseudostratified Columnar
http://www.visualsunlimited.com/browse/vu306/vu306638.html
Stratified Squamous
4
Endocrine System
Endocrine Glands:
Basal release of
hormones from ductless
glands into connective
tissue for transport by
blood
KIDNEY DIALYSIS METHODS
Endocrine Function:
•!Maintain homeostasis
•!Coordinate growth &
development
Endocrine System
STIMULUS
Stimulus Detection
Hormone Synthesis
Release
Endocrine cell:
Hormone Transport
Clearance
TARGET
Hormone Receptors
Signal Transduction
Target Response
Compare the properties of the endocrine and
nervous system.
STIMULUS
Endocrine cell:
Stimulus Detection
Hormone Synthesis
Release
Clearance
Hormone Transport
TARGET
Hormone Receptors
Target Response
5
Endocrine System
Paracrine Signaling: target is
local or near, hormone diffuses
through interstitial fluid
Autocrine Signaling: hormone
binds to receptors on hormonereleasing cell
STIMULUS
Classes of Hormones:
Is a hormone
transported in
blood alone or
bound to a
carrier protein?
What is the life time
of a hormone and how
is it cleared from the
body?
TARGET
Where are the hormone
receptors on the target cell?
Classes of Hormones:
Steroids:
Cholesterol derivatives
Hydrophobic, fat soluble
Transported bound to carrier proteins
Longer life time, slower clearance
Intracellular receptors
Regulate gene expression
Sex and stress hormones
Amino acid derivatives: Water-soluble, free transport
Stored in vesicles until release
Cell membrane receptors
Signal Transduction
Catecholamines
Thyroid hormone- EXCEPTION
Small peptides, polypeptides: Water-soluble
Often use carrier proteins
Cell membrane receptors
Signal Transduction
Hypothalamic and Pituitary hormones
Nonsteroid Hormone
Action
Second Messenger Systems:
cAMP
cGMP
tyrosine kinase
phosphatidylinositol
ion channel activation
http://www.cartage.org.lb/en/themes/sciences/
lifescience/GeneralBiology/Physiology/
EndocrineSystem/MechanismsHormone/
MechanismsHormone.htm
6
Hormone production & release: Feedback Mechanisms
-Response to a stimulus has an effect on the original stimulusNegative feedback: produces decrease in original stimulus
Positive feedback: produces increase in original stimulus
Steroid Hormone Action
Steroids and thyroid hormone
Direct gene regulation
chaperones: bind
- hormone
- DNA
- amino terminal
http://www.cartage.org.lb/en/themes/
sciences/lifescience/GeneralBiology/
Physiology/EndocrineSystem/
MechanismsHormone/
MechanismsHormone.htm
Hypothalamus and Pituitary
Hypothalamus: Functions
Sensory signals
Hypothalamus
Behavioral
Responses
Hormone release from
The Pituitary Gland
Activity of
Autonomic
Nervous System
7
Magnocellular
neurosecretory
neurons
Posterior Pituitary
NEURAL NOT ENDOCRINE
Oxytocin targets:
uterus- contraction
mammary glands- milk
ejection (let-down)
Posterior Pituitary
Vasopressin (ADH) targets:
kidneys- water retention
increase blood volume
decrease [Na+]
Posterior Pituitary: Pars nervosa
Infundibulum
Pars nervosa
Posterior Pituitary: Pars nervosa
Herring bodies: dilations filled with neurosecretory granules
(blue arrows)
Fenestrated capillaries
Pituicytes: astrocyte-like, associated with capillaries (red
arrow)
http://som.umdnj.edu/histology/lab22/lab22pituitary.html
http://medpics.ucsd.edu
8
Hypothalamic Control of the Anterior Pituitary
Anterior Pituitary is an endocrine gland.
Its hormone release controlled by hypothalamic hormones.
Parvocellular
neurosecretory
cells
Release
control
hormones
Hypothalamus
Target cells
Stimulate
or inhibit
hormone
release
Anterior
Pituitary
Target cells
Throughout
Body
Anterior Pituitary
Hormones
Follicle-stimulating hormone*
Luteinizing hormone *
Thyroid-stimulating hormone *
Adrenocorticotropin *
Growth Hormone
Prolactin
*tropic hormones: regulate
hormone release of target
cells
Anterior Pituitary
Pars tuberalis
Pars intermedia
Pars distalis
Anterior Pituitary: Pars Distalis
Parvocellular
Neurosecretory
Cells
Cell Classification based on staining
characteristics:
1)! Chromophobes- light staining;
Yellow arrows
2)! Acidophils- bright red staining; Blue
arrows
3)! Basophils- intermediately-stained;
Red arrows
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Cell Classification based on functional characteristics:
1)! Somatotropes: 50%, round nuclei, acidophilic, release
growth hormone (somatotropin); +release GHRH and ghrelin,
- release somatostatin
2)! Lactotropes: 15-20%, large polygonal,oval nuclei, acidophilic
vesicles -when released-chromophobe; prolactin; +THR and
VIP, -dopamine
3)! Corticotropes: 15-20%, medium polygonal, round eccentric
nuclei, basophils, PAS+, produce Adrenocorticotropin
(ACTH), MSH, enkephalin from precursor molecule POMC
(proopiomelanocortin); +CRH
4) Gonadotropes: 10%, small oval w/round eccentric nuclei,
basophil and PAS+, release follicle-stimulating hormone
(FSH) and luteinizing hormone (LH); +GnRH
5) Tyrotropes: 5%, large, polygonal, basophilia, PAS+, thyroidstimulating hormone (TSH), +TRH
Altered Hypothalamic/Pituitary
Function
Hussain Bisad
7feet 9 inches
Excessive Growth hormone
Giantism/Acromegaly
Tom Thumb
(2 feet 1 inch)
& P. T. Barnum
news.bbc.co.uk/.../south_east/6092086.stm?ls
Insufficient Growth hormone
Growth Hormone Deficiency
Dwarfism
www.pbs.org/.../special_dwarfism_ety.html
Thyroid
Thyroid Follicles
Epithelium: simple cuboidal or
low columnar
Follicular Cells
Follicular Cells
- produce thyroid
hormone
T3 and T4
- spherical nuclei
- basophilic
- microvilli
Parafollicular ( C ) Cells
- produce calcitonin
- follicule periphery
- within basal lamina
- pale staining
Fenestrated capillaries
Arranged around lumen
filled with acidophilic
colloid (PAS positive)
10
Parafollicular (C) Cells
THYROID: Follicular and Parafollicular cells
Calcitonin:
-! Calcitonin secreted in
response to increase in
blood calcium
-! Suppresses osteoclast
function, increase osteiod
calcification
-! Decreases blood calcium
levels
-! Physiological antagonist
to parathyroid hormone
Thyroid Hormone Synthesis
1) Follicular cells produce thyroglobulin and secrete it into
lumen
2)! Follicular cells actively take up iodide and it is oxidized to
iodine and released into the colloid.
3)! Tyrosine residues on thyroglobulin are iodinated to form
MIT and DIT. Mediated by thyroid peroxidase on apical
surface.
MIT= monoiodotyrosine
DIT= diiodotyrosine
thyroid peroxidase
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Thyroid Hormone Synthesis
4)! MIT + DIT form T3
DIT + DIT form T4
Still part of thyroglobulin in colloid
Thyroid Hormone Synthesis
Metabolic Activity:
T3 >>> T4
Amount released from Thyroid: T4 >>> T3 20:1
Transport in blood: Bound to transport (carrier) protein -->
Thyroxine-binding protein
Thyroid Hormone Synthesis
5) Upon stimulation with TSH (Thyroid Stimulating
Hormone), thyroglobulin is reabsorbed by receptor mediated
endocytosis and combine with lysosomes, releasing T3 and T4.
Thyroid Hormone Targets and Function
- Increases basal metabolic rate (BMR) (heat production)
- Accelerates protein synthesis in children
body growth and development
brain development
- Enhances sympathetic tone
T4 is converted to T3 in kidneys and liver
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Thyroid Hormone Targets and Function
Thyroid Hormone Receptor: intracellular, bound to DNA as
repressor without T3; with T3 present, acts as an activator of
gene transcription
Thyroid Hormone Release: Negative Feedback
Thyroid Releasing Hormone (TRH)
Thyroid Stimulating Hormone (TSH)
Thyroid Hormones (T3 and T4)
Diseases of the Thyroid
Iodine Deficiency: low T3 + T4, elevated TSH, goiter
Hypothyroidism
Diseases of the Thyroid
Hypothyroidism
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Diseases of the Thyroid
Hyperthyroidism
Diseases of the Thyroid
Graves Disease
Graves Disease:
T3 and T4
TSH
14

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