Endocrine 101

Question 1

6 hypothalamic functions

Answer 1

1. satiety/thirst
2. weight3. sleep
3. temperature control
4. circadian rhythm
5. glycemia

Question 2

outline a schematic represetnation of the interactions between higher centers, the hypothalamus, the pituitary grand and the peripheral endocrine glands.

Answer 2

the hypothalamus releases THYROID RELEASING HORMONE (TRH) to stimulate the pituitary, which can release TROPHIC HORMONE (TSH) which acts on the target gland (ex/ thyroid).

the Thyroid is activated and can produce hormones (ex/ thyroxine), which can be involved in a feedback loop to stop hypothalamic and pituitary hormone release.

Question 3

what hormones does the posterior pituirary release

Answer 3

2 hormones: ADH, oxytocin

Question 4

what hormones do the anterior pituitary release

Answer 4

1. growth hormoen
2. lutenising hormone LH
3. follicle stimulating hormons FSH
4. thyroid stimulating hormons TSh
5. ACTH: adrenocorticotrophic hormone
6. prolactin

Question 5

pituitatry gland top 5 functions

Answer 5

1. reproductive control
2. growth
3. metabolism/hemodynamic effects
4. lactation/labor
5. sodium concentration control

Question 6

name the posterior and anterior pituitary hormones

Answer 6

Question 7

growth hormone function

Answer 7

growth hormone is released from the anterior pitiuitary, and acts on multiple organs and muscles to promote their growth.

Question 8

how is the anterior pituitary gland stimulated to secrete growth hormone? what hypothalamic hormone inhibits the GH release? what liver chemical inhibits GH release

Answer 8

the APG releases Gh in response to GROWTH HORMONE RELEASING HORMONE secreted by the hypothalamus. if SOMATOSTATIN is released by the hypothalamus, GH release by the APG is inhibited.

when GH acts on the liver, IGF-1 is secreted and negatively feedsback to the pituitary and hypothalamic system.

Question 9

how does LH and FSH affect male endocrinology. Outline how it’s released

Answer 9

hypothalamus releases gonadotropin releasing hormone, which acts on the pituitary. the pituitary releases LH, which acts on Leydig cells to produce testosterone. the pituitary releases FSH, which acts on sertoli cells, which produces Inhibin and acts as a negative feedback regulator.

Question 10

LH and FSH release in males:

hypothalamus releases __ __ hormone, which acts on the pituitary. the pituitary releases __, which acts on ___ cells to produce __. the pituitary releases FSH, which acts on __ cells, which produces __ and acts as a negative feedback regulator.

Answer 10

hypothalamus releases gonadotropin releasing hormone, which acts on the pituitary. the pituitary releases LH, which acts on Leydig cells to produce testosterone. the pituitary releases FSH, which acts on sertoli cells, which produces Inhibin and acts as a negative feedback regulator.

Question 11

outline how LH and FSH acts in female endocrinology

Answer 11

hypothalamus releases GnRH, which stimulates the pituitary gland which releases LH. LH acts on the ovary, which produces progesterone and estradiole. FSH causes Inhibin release, which acts as a negative feedback reguarot

Question 12

Function of TSH release. Outline mechanism of release

Answer 12

acts to help sodium concentration control.

hypothalamus releases thyroid releasing hormone (TRH). TRH acts on the ANTERIOR pituitary gland, which releases TSH (thyroid stimulating hormone). TSH acs on the thyroid gland, which releases T4 and T3. T4 and T3 act on the liver and also act as negaitve regulators in the hypothalamus

Question 13

TSH mechanism;

hypothalamus releases thyroid ____mone (TRH). TRH acts on the __ pituitary gland, which releases __ (thyroid stimulating hormone). TSH acs on the __ gland, which releases __ and __. __ and __ act on the _ and also act as negaitve regulators in the __

Answer 13

hypothalamus releases releasing hormone (TRH). TRH acts on the ANTERIOR pituitary gland, which releases TSH (thyroid stimulating hormone). TSH acs on the thyroid gland, which releases T4 and T3. T4 and T3 act on the liver and also act as negaitve regulators in the hypothalamus

Question 14

outline the hypothalamic pituitary adrenal axis

Answer 14

hypothalamus releases CRH, CRH stimulates the anterior pituitary, which releases ACTH. ACTH acts on the adrenal glands to produce cortisol.

Question 15

Cortisol is a ___ regulator of ADH and CRH

Answer 15

negative regulator of ADH and CRH

Question 16

Note: Cortisol function

Question 17

function of prolactin

Answer 17

affects lactation.

Question 18

the difference in prolactin compared to other hormones is that is ___ controlled, as opposed to the other hormones that are controlled via a releasing hormone causing their release.

In prolactin, it is always being produced, but it gets suppressed by ___

Answer 18

the difference in prolactin compared to other hormones is that is NEGATIVELY controlled, as opposed to the other hormones that are controlled via a releasing hormone causing their release.

In prolactin, it is always being produced, but it gets suppressed by DOPAMINE

Question 19

outline the modulation of prolactin

Answer 19

sleep, stress and suckling stimulus acts on the hypothalamus natrually to release TRH, which acts on the pituitary, which produces prolactin. THIS HAPPENS NORMALLY.

hypothalamus releases DOPAMINE which can inhibit the prolactin secretion

Question 20

how many hormones are released from the anterior pituitary

Answer 20

2; ADH and oxytocin

Question 21

When referring to the cause of the deficiency or
excess, we use an anatomically distinguishing nomenclature for pituitary mediated hormones:

Answer 21

primary, secondary, tertiary.

tertiary and secondary pituitary hormones feedback to central structures like the pituitary itself or the hypothalamus

the primary hormones act on a target cell/gland like the thyroid

Question 22

4 functions of the parathyroid glands

Answer 22

A. Control serum Calcium levels

B. Control serum Phosphate levels

C. Control bone health

D. Control renal excretion of Calcium

Question 23

Function of Exocrine Pancreas

Answer 23

Digestive enzymes released into the
pancreatic duct and duodenum • Eg. Lipase, amylase, protease..etc

Question 25

what hormones are released in the endocrine pancreas?

Answer 25

insulin, glucagon

Question 26

• Cortisol level measured and is low
• ACTH is 4000, what is your Dx?

A. primary adrenal insufficiency

B. central adrenal insufficiency

Answer 26

A. primary adrenal insufficiency

-The problem is that cortisol is low , pituitary is doing everything it can to fix that. The failure is on the adrenal gland, it is failing to respond to the pituitary hormones.

Question 28

• Patient with clinical suspicion of low cortisol • Lab testing confirms low cortisol • “normal” ACTH
• Dx:

A. Primary adrenal insufficiency

B. Central adrenal insufficiency

Answer 28

B: central adrenal.

Low cortisol; the only acceptable is a super high ACTH. If its normal or low, its inappropriate/not enough. This is lack of reserve in the central part of the axis–problem in the hypothalamus or pituitary

Question 29

different types of release

Answer 29

1. pulsatile secretion
2. circadian rhythm
3. negative feedback inhibition

Question 30

type of release?

Answer 30

Pulsatile release.

Ex/ growth hormone

Question 31

type of release?

Answer 31

circadian rhythm; ex in cortisol

Diurnal variation of glucocorticoids: peak 4am to 8am, Nadir 11pm to 4am

Question 32

What time of day would you order a cortisol level if deficient? if you wanna see if there is cortisol excess?

Answer 32

id deficient;; check at 8am when it should be at its peak

if in excess, check at midnight when it should be low (at nadir)