(25-2) Hypothalamus/Anterior Pituitary

Question 1

(Special Portal System)

1. capillaries in HT pick up HT hormones and carry them where?
2. Relationship between NT and anterior pituitary neural or endocrine?
3. Are HT hormones delivered to pituitary directly or indirectly? in what concentration?
4. Do hormones circulate systematically?

Answer 1

1. second capillary bed in anterior lobe
2. another trick question bitch, it’s both
3. directly; high concentration
4. no (and there half life is short)

Question 2

(Hypothalamic Hormones)

(What does each of these stand for?)

1. GHRH
2. TSH
3. CRH
4. PIH
5. GnRH

Answer 2

1. growth hormone regulating hormone
2. Thyroid stimulating hormone
3. corticotropin releasing hormone
4. prolactin inhibiting hormone
5. gonadotropin releasing hormone

(i imagine you will cover all of this later - but if not go over this stuff)

Question 3

(Anterior Pituitary Lobe Hormones )

How many families are there?

what are the three families?

Answer 3

1. 3
2. FSH, LH, TSH
3. ACTH
4. GH and Prolactin

Question 4

learn this

Question 5

(TSH, LH and FSH Family)

1. all what kind of protein?
2. How many subunits?
3. What subunit is identical?
4. What conferes biologic specificity?
5. Where do alpha and beta get paired up?

Answer 5

1. glycoprotein
2. 2 (alpha and beta)
3. alpha
4. beta
5. ER and golgi

(hCG (human chorionic gonadotropic-placenta)

Question 6

(Gonadotropins: LH and FSH)

1. regulate reproduction by doing what?
2. LH stimulates secretion of what from the gonads?

(LH in males)

3. binds to what to stimulate what?

(LH in Females)

4. Ovarian theca cells respons to LH how?

Answer 6

1. stimulating gonads
2. sex steroids
3. binds to receptors on Leydig cells to stimulate synthesis and secretion of testosterone
4. secretion of testosterone (which is converted into estrogen by granulosa cells)

Question 7

(Control of Gonadotropin Secretion)

1. What hormone does this?
2. makeup?
3. What kind of feedback loop?
4. What other 2 hormones do gonads secrete?

Answer 7

1. GnRH (LHRH)
2. 10 aa peptide
3. classic negative
4. inhibin (inhibits FSH) and activin (activates FSH)

Question 8

look at this a little

kisspeptin is a strong simulator of GnRH secretion

6 steroids affect kisspeptin

I wouldn’t t

Question 9

(Follicle Stimulating Hormone)

1. FSH stimulates what?
2. Exogenous FSH used to cause what?
3. Critical for production of what? by supporting what?

Answer 9

1. maturation of follicles
2. “superovulation”
3. sperm production; sertolli cells (which support sperm production)

Question 10

(Luteinizing Hormone)

1. Ovulation of mature follicles is induced by what? called what?
2. Post ovulation in the follicle becomes a what? can secrete what two things?

Answer 10

1. large burst of LH; Preovulatory LH surge
2. a corpora lutea; progesterone and estradiol

Question 11

(TSH)

1. stimulated by what hormone?
2. causes the secretion of what at thyroid gland?
3. what kind of protein?
4. Promotes growth of what?
5. increases intrathyroidal deiodination of T4 to T3
6. initiates uptake of what from the blood by thyroid gland?

Answer 11

1. Thyroid releasing hormone (TRH)
2. T4 and T3
3. glycoprotein
4. thyrocyte growth
5. -
6. iodide

*I think circulating thyroid hormones inhibit release of TSH (negative feedback)

Question 12

(Endogenous TSH as a clinical tool)

Hypothyroid - 3 possibilities (making too little hormone)

1. Primary hypothryoidism due to what?
2. Secondary?
3. Tertiary?

Answer 12

1. thyroid gland dysfunction (not enough T3 and T4)
2. pituitary dysfunction (not enough TSH from thyrotropes)
3. hypothalamus dysfunction (not making TRH from neurons)

Question 13

TSH is decreased/elevated in 60-80% of hypothyroid dogs