Which of the following cells secretes calcitonin?
a. principle cells of the thyroid
b. parafollicular cells of the thyroid
c. oxyphil cells of parathyroid
d. principle cells of the parathyroid
b. parafollicular cells of the thyroid
Which region of the suprarenal gland manufactures and secretes epinephrine?
b. zona glomerulosa
c. zona fasiculata
d. zona reticularis
A. medulla under sympathetic control secretes nonepi and epi
Thyroid hormones T3 and t4 are store in which of the following?
a. herring bodies
c. principle cells of follicle
d. parafollicular cells
WHich of the cells indicated secretes the hormone that lowers blood sugar.
A. (blue) beta cells
B. (pink cells) Alpha cells
C. (gray) delta cells
A. Blue = beta cells secrete insulin.
The hormone vasopressin is released from which specific region of the hypophysis?
pars nervosa - neurohypophysis
Identify those portions of the hypophysis that arose from the roof of the oral cavity?
pars distalis up to stalk
Features of Endocrine system
-Functions w/ nervous sys to regulate body processes and maintain homeostasis
-slower than neurological response (sometimes days.)
-Hormonal effects last sec, wks, mos
-organic substances secreted by a cell that have effect on function of another cells either close by or far away
-released into extracellular space to go to BV
-action restricted to target cells with receptors for them
AA, bonded by peptide chain
(admin IV, InMusc, Subcutaneous)
AA with NO peptine bonds- has NH2 group
-thyroxine TG, Adrenaline ADRE, Melatonin Pineal
(admin oral-IV -or inhale
Endogland secretes hormone until target cells send message back that they have enough
This message inhibits secretion.
When singal inhib is low it starts to secrete again
Pars tuberalis (like tube at stalk)
Pars Intermedia (gone in humans)
Pars distalis (the sac) *most active
Nervous portion derived from "down growth" of brain.
- Hormones synthesized in hypothalamic nuclei of brain. come down neuronal processes and stored in terminal azonal regions in neurohypophysis
Hormones of Neurohypophysis
ADH (vassopressin)- decrease uring production anti-diuretic
OXYTOCIN (+feedback) contraction at birth; "love" and sexual arousal M and F
Location: below larynx
Has 2 lateral lobes connected by isthmus
A-larynx, B/C-lateral lobes d-isthmus
Composed of follicles surrounded by cubodial epithelia.
Principal Cells=cubodial epithelia
Hormones of ThyGl
Thyroxine (Amine ) T4 (iodine)
Triiodothyronine (amine) T3 more potent than T4
Calcitonin (produced by cells between folicles) from parafollicular cells.
T4 - T3
-iodine necessary for them to form
-synthesized by principal cells pr THYGL follicles
-synthesized and stored in follicle as colloid until released.
-made by parafollicular cells
-regulates calcium - decreases blood Ca by inhibiting osteoclasts and increases secretion of Ca by the kidneys.
No bone death - Ca released kidney
Pathway of hormone release
TH (adrenal cortex)
Like butterfly, on posterior surface of Thy GL.
Small yellow-brown organs-separated from THYGL by capsulate
Principal cells (chief cells) synthesize the hormone)
-oxyphil cells secrete nothing but support chief cells.
Effects of parathyroid Hormon PTH
-increase in blood Ca
stimulates osteoclasts to reabsorb bone and causing kidneys to retain calcium
Bone death , kidney Ca retention
(inhibits urinary secretion of Ca, and increases interstitial Ca resorption)
Suprarenal cortex has 3 layers
Glomerulosa-mineralcoritcoids (Na and K regulation)
Fasciculate-glucocorticoids (affects glucose metabolism-
Reticularis-gonadocorticoids (sex hormones) androgens, estrogen
Pathway for Suprarenal Hormones
Cortisol (adrenal cortex)
Three types of cell in an islet
Alpha cells (pink) -glucagon- raise blodd glucose by breaking glycogen to glucose and then releasing it.
Beta cells (blue) secrete insulin - lowerd blood glucose levels by removing glucose and storing it as glycogen
Delta cells- orange- secrete somatostatin inhibits both insulin and glucagon.
Located deep in brain
(decrease retina light =increase melatonin)
-function in circadian rhythms.
What hormone is secreted by the parathyroid
gland and what is its function?
Parathryoid hormone (PTH)—increases free Ca2+ levels by increasing calcium absorption in the intestines, inhibiting Ca2+ secretion in the urine, and by increasing osteoclast activity in bone.
How are the parathyroid glands antagonistic to
the thyroid gland?
Release of PTH from the parathyroid hormone leads to an increase in free Ca2+ levels in the blood (reasons stated above in question 2416). However, calcitonin, which is released by the thyroid gland, decreases circulating levels of Ca2+ by inhibiting the bone-resorbing activity of osteoclast