Endocrine Fun Facts

Question 1

Graves Disease

Answer 1

1. Thyroid Enlargement
2. Exophthalmos
3. increased antibody TSH-R-Ab (stim)) causes opthalmopathy and pretibial myxedema. Due due GAG deposits in the bones and eyes
4. Decreased TRH,TSH
5. TSH-R-Ab comes along and stimulates the thyroid gland and this causes increase production of thyroid hormones.
6. Tx –> beta blocker or iodine blocker
7. If left untreated = thyroid storm

Question 2

cAMP second messenger systems?

Answer 2

1. Glucagon
2. ACTH
3. ADH (V2)
4. LH/FSH
5. TSH
6. Epi/norepi (beta receptor)
7. Somatostain
8. GHRH
9. dopamine
10. CRH
11. HCG
12. PTH

Question 3

Receptor Associated Tyrosine kinase messenger systems?

Answer 3

GH
Prolactin
GNRH

Question 4

Tyrosine Kinase messenger systems?

Answer 4

Insulin

IGF-1

Question 5

Intracellular messenger systems?

Answer 5

Steroid Hormones (all cortical hormones aldosterone, cortisol, epi/ne) 
Iodothyronines 
Ca in blood

Question 6

IP3/DAG messenger systems?

Answer 6

ADH (V1) and PTH 
GNRH
Oxytocin 
TRH
Histamin (H1)
Angiotension II 
Gastrin

Question 7

Which hormone is responsible for preventing milk production during pregnancy?

Answer 7

High levels of estrogen and progesterone

Question 8

How would you inhibit thyroid hormone synthesis?

Answer 8

Ingest excess Potassium Iodide (wolff-Chaikoff Effect: Transient inhibition of T4/T3 release by inhibition of I pump)

Question 9

what hormones are high during pregnancy?

Answer 9

Estrogen

Corticosteroid binding globulin (CBG/transcortin)

Question 10

PTH secreting hormone?

Answer 10

Primary hyperparathyroidism
excess PTH causes increased calcium (serum and urine) and phosphaturia and PUD
(stones, bones and abdominal groans)
Secondary hyperparathyroidism
diet deficient in Vit D
normal Ca in serum and decreased urine Ca
decreased serum phosphate levels and increased urine PO4 levels

Question 11

Addisons Disease

Answer 11

Primary Adrenocortical Disease
Autoimmune destruction of all zones of the adrenal cortex
loss of all hormones
increased secretion of ACTH and hyperpigmentation of skin secondary to alpha MSH molecule secretion

Question 12

Male without testosterone receptors, what happens?

Answer 12

Less negative feedback so LH increases (less testosterone production)

Question 13

What is androgen binding protein important for?

Answer 13

keeping the testosterone level in the seminiferous tubule high

Question 14

In the second trimester progesterone is made mainly by what?

Answer 14

placenta (corpus lutem for the first trimester)

Question 15

what anterior pituitary hormone will be elevated in lactating women compared to non pregnant women?

Answer 15

lactating woman will have higher prolactin

Question 16

What will increase prolactin?

Answer 16

Dopamine receptor antagonist

Question 17

Proliferative phase. when does it happen and what hormone is responsible ?

Answer 17

Estrogen

days 5-14 (preovulation, preparation of endometrium for implantation)

Question 18

What is the difference between primary and secondary hyperaldosteronism?

Answer 18

Primary –> adrenal tumor that is secreting aldosterone

Secondary –> Increase renin levels

Question 19

Give some features of growth hormone

Answer 19

1. large hormone with a long half life
2. secreted by somatotrophs in the AP
3. Skeletal and Soft tissue growth
4. Increase production with exercise, hypoglycemia and stress
5. GH binds to receptor and acts on tyrosine kinase
6. Somatostatin(GHIH) inhibits the secretion of GH
7. Occurs in periodic bursts with max peak at night

Question 20

Gives the actions of GH in the liver, adipose tissue and muscle

Answer 20

Liver: Increases glucose synthesis –> Increases BG
increases IGF synthesis –> increases IGF
Increase synthesis of IGF binding protein –> Increase IGF-BP
Adipose Tissue: Increases lipid breakdown –> Increases FFA and glycerol
Decreases Glucose Uptake –> Increases BG
Muscle: Increases AA uptake and therefore Increase Protein Synthesis
Decrease Glucose uptake–> increases BG

Question 21

Thyroid Hormone T4 (thyroxine) and T3 (tri-iodothyronine)

Answer 21

1. T3 –> 9% but much more potent and physiological active form
2. T4 –> 90% but much less potent (unbound form is active)
   3 .Both released from follicular cells of the thyroid gland
3. T3 provides a negative feedback mechanism on the hypothalamus
4. TRH–>AP–>Thyroid gland –> thyroid hormone

Question 22

Thyroid hormone synthesis

Answer 22

Made from iodination of tyrosine molecules grouped together in thyroglobulin
70% of T3 and T4 are bound to thyroxine binding globular (TBG)
Pregnancy and estrogen levels increase TBG

Question 23

If there is a pump failure or some issue with the iodine pump then what happens?

Answer 23

If no I- or I0 then T4 and T3 can not be synthesized and this leads to increased TSH levels.

Question 24

What enzyme converts T4 to T3?

Answer 24

5’- deiodinase

Question 25

Actions of Thyroid Hormone?

Answer 25

Increase Oxygen consumption and heat production of most cells increase basal metabolic rate increases intracellular mitochondria, resp enzyme, Na/K pump and other enzymes (which leads to increase O2 and metabolic rates) increases glucose absorption from the GIT increases use of glucose fat and protein for energy use. glycogenesis and gluconeogenesis decreased body weight

Question 26

PTH

Answer 26

Produced from chief cells short half lives most important regulator for Ca Decreased ionized Ca in blood --> parathyroid gland --> increased PTH converts 25-hydroxycholecalciferol in the liver to 1,25 Oh cholecalciferol in the renal cortex inhibits phosphate reabsorption in the proximal tubule increases calcium reabsorption in the DCT

Question 27

Action of PTH on bone

Answer 27

Osteoclast development and action (increases bone reabsorption)

Question 28

Insulin secretion post meal (post prandial state) ?

Answer 28

After eating a meal insulin secretion is increased. As a result, there is an increased rate of glucose uptake by both the liver and the muscle. Insulin also inhibits hormone sensitive lipase, which decreases hydrolysis of triglycerides in fat cells.

Question 29

ATP blocks what from leaving the cell?

Answer 29

K efflux therefore this leads to insulin synthesis

Question 30

Cortisol (Zona fasciculta)

Answer 30

Main glucocorticoid in the body highest levels at 8am and lowest at 12pm ACTH --> Receptor--> increased cAMP --> increased PKA---> phosphorylation of proteins Function--> adaptive response to stress and fasting only negative feedback system onto the AP in the zona fasciculta and zona reticularis metabolized in the liver and excreted in the urine crosses the blood brain barrier increases insulin secretion and increase glucose and increase AA breakdown as well as protein breakdown

Question 31

Prolactin

Answer 31

negative feedback system big peptide so long half life main functions is breast development and milk production NOT EJECTION inhibits ovulation in lactating females and suppresses GnRH synthesis and release and decreases sex drive Hypothalamus (PIF) --->Anterior Pituitary (prolactin) --> decreased prolactin really high levels of estrogen (like during pregnancy) or TRH stimulate prolactin release)

Question 32

what is an example of a dopamine agonist?

Answer 32

bromocriptine

Question 33

During menopause which hormone is the highest?

Answer 33

increase in FSH and LH (FSH is more though)

Question 34

Initiation of Partuition?

Answer 34

estrogen to progesterone ratio?

Question 35

hCG acts on LH receptors to maintain what?

Answer 35

maintain progesterone levels and keep corpus luteum active

Question 36

Fetal Hormone Production

Answer 36

idk

Question 37

ABP maintains what?

Answer 37

testoterone levels in the semineferous tubules

Question 38

lady comes into the ER with a broken leg, she has low Ca with brittle bones and high PTH

Answer 38

secondary hyperparathyroidism

Question 39

what does effect does an increased T3/T4 have on TSH?

Answer 39

Lowers TSH due to neg feedback system

Question 40

what affect does increased secretion of cortisol from the adrenal cortex have on ACTH?

Answer 40

Lowers ACTH again due to the neg feedback system

Question 41

patient takes GH levels at 6am after fasting 10 hour, take GH levels 1 hour before eating which hormone will be the lowest?

Answer 41

insulin

Question 42

what hormones are elevated to inhibit lactation?

Answer 42

progesterone and estrogen

Question 43

what hormone is elevated and needed for milk ejection?

Answer 43

oxytocin

Question 44

what is high in a sample with 21 alpha hydroxylase deficiency?

Answer 44

ACTH high because your not making aldosterone or cortisol

Question 45

somatostatin binds to anterior hypothalamus, what is the mechanism?

Answer 45

GI --> reducing cAMP

Question 46

increase number of binding globulins what do you increase?

Answer 46

increase half life

Question 47

patient comes into the ER that is hypoglycemic, hypovolemic and hypoglycemic. what is deficient?

Answer 47

low cortisol

Question 48

what happens if the liver stops secreting IGF?

Answer 48

decrease in somatostatin

Question 49

beta cell, glucose binds what is the mechanism?

Answer 49

increase in ATP inhibits K channel | opens Ca channel

Question 50

what does cortisol upregulate in the adrenal medulla?

Answer 50

PNMT

Question 51

which value is higher in umbilical artery/vein?

Answer 51

PCO2 higher in artery