Term
| All endocrine cells are ____ cells. The glands (have/don't have) ducts. The glands lie in a ________. |
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Definition
-Epithelial
-Don't have
-Large vascular bed |
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Term
| What are the 2 types of specialized capillaries? What do they do? |
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Definition
-Fenstrated capillary w/ diaphragm, Sinusoidal capillary
-Allows leakiness and permeability
-SC gave no tight junctions or BMs
-SC are lined with non-phagocytic fixed macrophages |
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Term
| What do the cells look like that secrete modified amino acids? What are some examples? |
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Definition
Eosinophilic non-granular cytoplasm
Epi, norepi, thyroid hormones |
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Term
| What do the cells look like that secrete pure polypeptides/proteins? |
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Definition
| Serous cells with granular cytoplasm |
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Term
| What do the cells look like that secrete glycoproteins |
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Definition
| Serous cells with granular cytoplasm, hormones are glycosylated |
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Term
| What do the cells look like that secrete steroids? |
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Definition
| Large SER, foamy eosinophilic non-granular cytoplasm |
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Term
| What is the difference between endocrine, paracrine, and autocrine factors? |
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Definition
Endo- travels through blood, effect far
Para-spreads through CT matrix, effect close by on different tissue
Auto-receptor on same gland, effect on same type of tissue |
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Term
| How does a ligand-gated channel work? |
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Definition
Receptor binds
Ca+ gates open
Ca+ influx
Activates protein kinases |
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Term
| A transmembrane receptor an example of what type of receptor? |
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Definition
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Term
| What happens when a Gs hormone binds? |
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Definition
Cleaves GTP
Activates Adenylyl Cyclase
Inc cAMP
Activates protein kinases |
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Term
| What happens when a Gi hormone binds? |
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Definition
Cleaves GTP
Inactivates adenylyl cyclase
Dec cAMP
Inactivates protein kinases |
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Term
| What happens when a Gp hormone binds? |
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Definition
Cleaves GTP
Activation of Phospholipase-C
Splits membrane phospholipids
(other stuff)
Inc cGMP
Activates protein kinases |
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Term
| What are the 4 parts that Rathke's pouch develops into? |
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Definition
Pars Tuberalis-wrapped around infund.
Pars Distalis-anterior, swells
Pars Intermedia-didn't grow
Residual lumen |
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Term
| What does the infundibulum develop into? |
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Definition
Neural stalk-outpocking growing down
Pars Nervosa-swollen bulbous part |
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Term
| Hypertrophy of the pituitary may cause what? |
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Definition
| Visual impairments - sits very close to optic chiasm |
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Term
| What makes up the anterior and posterior lobes of the pituitary? What about the stalk? |
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Definition
Ant = Pars distalis
Post = Pars nervosa, Pars Intermedia
Stalk = Pars tuberalis, Neural stalk |
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Term
| What does adenohyphsis and neurohypohysis associate with? |
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Definition
Adeno - from Rathke's pouch: Pars Intermedia, Pars tuberalis, Pars distalis
Neuro-from infundibulum : Neural stalk and pars nervosa |
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Term
| What is the only organ where you'll find both fenestrated and sinusoidal capillaries? |
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Definition
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Term
| What is the only organ where you'll find both fenestrated and sinusoidal capillaries? |
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Definition
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Term
| Where do the capillaries that nourish the gland originate from? What about those that transport hormones? |
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Definition
Nourish - from Circle of Willis
Transport - from Hypothalamus |
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Term
| Where are the interconnecing veins between the 2 capillary beds of the pituitary located? |
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Definition
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Term
| Where is the 1st capillary bed of the pituitary located and which type of capillaries? |
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Definition
| Hypothalamus, fenestrated |
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Term
| Where is the 2nd capillary bed of the pituitary located and which type of capillaries? |
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Definition
| Pars distalis, sinusoidal |
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Term
| What are the 2 types of cells in the pars distalis? |
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Definition
| Chromophobes and Chromophiles |
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Term
| Which cells in the pars distalis are inactive/don't produce horomes, and are reserve cells until activated? |
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Definition
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Term
| How many different chromophile cells are there? How many stain? |
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Definition
7 types for 7 hormones
-only 2 different stain, red (3/4)and blue (1/4) |
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Term
| What do acidophile cells looks like? |
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Definition
Polyhedral
Larger than chromophobes, smaller than basophiles
Cluster in center of pars distalis
Eosinophilic serous granules @ top |
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Term
| What do mammotroph cells produce? What type of cell are they? |
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Definition
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Term
| What do Somatotroph cells produce? What type of cell are they? |
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Definition
Somatotropin/GH
Acidophile |
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Term
| How do mammotroph and somatotroph cell appearances differ? |
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Definition
Mammo-large irregular granules, stains with erthrosin
Soma-smaller regular granules, stains with orange-g |
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Term
| What is the function of prolactin? |
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Definition
-Induce breasts to produce milk (not secrete)
-Mitogenic for ova and sperm
-Maternal behavioral patterns |
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Term
| Where do somatostatins come from? |
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Definition
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Term
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Definition
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Term
| Under-production of GH affects what? |
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Definition
| Growth of long bones but not really flat bones - normal trunk with small limbs, different from midget |
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Term
| Tumor of the somatotroph cells leads to what? |
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Definition
| Acromegaly - plate have already fused, height not affected but has extra bone deposition |
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Term
| Which cells are the largest of the pars distalis? |
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Definition
| Basophiles - more irregular and oval than acidophiles |
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Term
| Where do basophiles tend to sit? What do they stain with? |
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Definition
Cluster together at outer edges of pars distalis
-PAS |
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Term
| What do throtroph cells produce? What type of cell are they? |
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Definition
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Term
| What do gonadotroph cells produce? What type of cell are they? |
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Definition
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Term
| What do Corticotroph cells produce? What type of cell are they? |
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Definition
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Term
| How do thyrotroph, gonadotroph, and corticotroph cell appearances differ? |
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Definition
Thyro-long spindle shape, irregular purple granules
Gonado-Round w/ medium blue granules
Cort-small red granules |
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Term
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Definition
| Induces production and secretion of thyroid hormones |
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Term
| For normal production of testosterone what hormones must both be present? |
|
Definition
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Term
| In women, what do FSH and LH do? |
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Definition
FSH - induces growth of ovarian follicle
LH - Induces ovulation |
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Term
|
Definition
| Stimulates adrenal cortex to secrete its steroid hormones |
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Term
|
Definition
| Stumulates melanocytes to produce melanin |
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Term
|
Definition
| Stumulates melanocytes to produce melanin |
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|
Term
| What is Addison's disease? |
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Definition
Too much ACTH activity, skin gets darker
-ACTH has some MSH activity |
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Term
| T or F: The cells in the pars tuberalis produce hormones |
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Definition
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|
Term
| T or F: The pars intermedia secretes hormones |
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Definition
| False, except in fish amphibians and chameleons where they produce MSH equivalent Intermedin |
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Term
| What type of tissue is in the pars nervosa? |
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Definition
| Grey matter, with unmyelinated nerve fibers in parallel, no cell bodies |
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Term
|
Definition
| Large supporting glial cells in the pars nervosa |
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Term
| What are herring bodies? What do they store? |
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Definition
Dilated endings of golgi-type 1 unmyelinated axons with storage granules in the pars nervosa
-Store hormones produced in hypothalamus |
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Term
| Where is oxytocin produced? What does it do? |
|
Definition
-PVC, some in SON
-Induces smooth muscle contractions for labor and milk secretion |
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Term
| Where is ADH produced? What does it do? |
|
Definition
-SON, some in PVN
-Conserves water and sodium to inc BP |
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Term
| What is the general structure of the thyroid gland? What surrounds it? What holds it in place/supports it? |
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Definition
-Bi-lobed, connected by isthmus
-Dense irregular fibro-elastic CT
-Superior cervical fascia |
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|
Term
| What is the stroma of the thyroid gland made of? |
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Definition
| Areolar CT surrounded by fenestrated capillaries |
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Term
| What is the basic functional unit of the thyroid gland? What type of tissue is it? |
|
Definition
-Follicle
-Simple cuboidal on BM
But changes with activity
TSH - columnar
Storage phase - low cuboidal |
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|
Term
| What does the follicle cells of the thyroid gland produce? |
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Definition
| Thyroglobulin, proteases, iodinases |
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Term
| What do thyroglobulin, proteases, and iodinases do? |
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Definition
-Thyroglobulin acts as carrier until hormones are needed
-Proteases split them when ready
-Iodinases attach onto thyroid hormone precursors |
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|
Term
| What is progressive iodinization? |
|
Definition
-Follicle picks up tyrosine
-Converts to Thyronin
-Thyronin gets 1st iodinization
-1st always in cytosol
-T1 released out apical end to colloid
-T1 binds to thyroglobulin
-Gets iodinized 3 more times = T4, remains bound until needed |
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Term
| What is the most potent form of thyroid hormones? |
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Definition
| T3, but T4 controls TSH feedback loop |
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Term
| T or F: Thyroid hormones do not require membrane-bound receptors |
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Definition
| True - they are membrane soluble |
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|
Term
| How is specificity dictated with thyroid hormones? What does it do? |
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Definition
NOT receptors
Presence of tetra-iodo-thronin-delodonase
-CONVERTS TO T3 |
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|
Term
| What must thyroid tests test for? |
|
Definition
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Term
| What do parafollicular cells look like, what do they do, and where are they? |
|
Definition
Thyroid gland
Clear cell
Come from endoderm of pharyngeal pouch
Calcium homeostasis |
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Term
| What does the parafollicular cells secrete? When? |
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Definition
Calcitonin (produce and secrete)
When plasma Ca levels are high |
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|
Term
|
Definition
Inactivates osteoclasts - inhibit bone resorption
Stimulates osteoblasts - deposit more Ca into bone
*binds to osteoclasts |
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|
Term
| Which trigeminal layer do follicular cells come from? What about parafollicular cells? |
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Definition
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Term
| What is the basic structure of the parathyroid glands? What are they enclosed by? What's the stroma made of? |
|
Definition
-4 separate lobes, each adhere to posterior of thyroid
-Areolar fibro-elastic CT
-Reticular CT |
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|
Term
| T or F: Thyroid and parathyroid glands share circulation |
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Definition
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|
Term
| What are the 3 types of cells in the parathyroid gland? |
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Definition
Dark Chief Cells, Pale Chief cells, Oxyphil cells
*chief or principle |
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Term
| How do the dark and pale chief cells of the parathyroid gland differ? What stages are they in? |
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Definition
Dark-small dark nucleus, has granules, active storage phase
Pale-large light nucleus, no granules, active production phase (making more PTH, it's already been secreted) |
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Term
| What do oxyphil cells look like? What are they? |
|
Definition
-Large clustered cells
-Dark nucleus
-Pink non-granular cytoplasm
"Reserve" cells in inactive phase
Can be activated on demand |
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|
Term
| What does PTH do? When is it secreted? |
|
Definition
Inactivates osteoblasts
Activates osteoclasts
When low plasma Ca levels |
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|
Term
| What can decrease skeletal mass? |
|
Definition
Low estrogen
High PTH
High thyroid hormones
High glucocorticoids |
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|
Term
| Where does the adrenal cortex come from? the medulla? |
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Definition
Cortex - mesoderm
Medull - ectoderm |
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|
Term
| What is the adrenal cortex covered by? |
|
Definition
| Dense irregular fibro-elastic CT |
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|
Term
| What are the 3 layers of the adrenal cortex? |
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Definition
| Zona: glomerulosa, fasiculata, reticularis |
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Term
| What does the zona glomerulosa look like and what is it involved in? |
|
Definition
Knots of columnar EP
True fenestrated capillaries
Produces Aldosterone under control of angiotensin II
SALT |
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Term
| What does the zona fasiculata look like and what does it do? |
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Definition
Single layer of tall-cuboidal EP
Sinusoidal capillaries
Produces glucocorticoids by spongiocytes under control of ACTH
SUGAR |
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Term
| What does the zona reticularis look like and what does it do? |
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Definition
Networking cords of low-cuboidal EP
Sinusoidal capillaries
Produces sex androgens
SEX |
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|
Term
| What is the basic structure of the adrenal medulla? |
|
Definition
| Golgi type II motor ganglia of ANA synapsing with chromaffin cells |
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|
Term
| Of the adrenal glands which has venous system which has arterial? |
|
Definition
Cortex - arterial
Medulla - venous |
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|
Term
| T or F: The adrenal gland is under control of ACTH |
|
Definition
| False - NOT medulla, functions as a ganglion, synapses w/ chromaffin cells, then they secrete |
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|
Term
| What does the adrenal medulla secrete? |
|
Definition
| Catecholamines - epi and norepi |
|
|
Term
| What does the pineal gland develop from? |
|
Definition
Epiphysis of the diencephalon
Derived from grey matter of brain but does not have any perikarya |
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|
Term
| What are pinealocytes involved in? |
|
Definition
| Light-dependent metabolism of tryptophan -> serotonin -> melatonin |
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|
Term
| What occurs in the pineal gland at night? day? |
|
Definition
Night - no light, serotonin dec melatonin inc
Day - Light, serotonin inc, melatonin dec
Get diurnal rhythms |
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|
Term
| When do melatonin and seratonin peak? |
|
Definition
Melatonin - 11pm to 7am
Seratonin - light hours |
|
|
Term
| How is wakefulness controlled? |
|
Definition
By serotonin
-goes to hypothalamus' SCN's RAS
-Active RAS = you wake up
-Inactive RAS = get sleepy |
|
|
Term
| What happens if you have elevated melatonin chronically? |
|
Definition
Male - Dec FSHRH and LHRH, dec FSH&LH, decreases testosterone (decreased sperm and sex drive)
Female - dec LHRH only, dec estrogens, no ovulation (decreased fertility and sex drive) |
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