Pituitary Physiology and Path

Question 1

What is long loop vs short loop feedback? Ultra-short loop?

Answer 1

Long: Target organ fb to Hypothal or Anterior pituitary

Short: Ant Pit fb to Hypothal

Ultra-short: Hypothal to Hypothal

Question 2

How are the hypothalamus and pituitary related to each other?

Answer 2

.

Question 3

What hormones are made and released by the Hypothalamus?

Answer 3

CRH > ACTH
TRH > TSH + Prolactin
GRH > FSH, LH
GHRH
GHIH (somatostatin)
PIH (prolactin inh) (dopamine)

Question 4

What is the role of the Ventromedial nucleus?

Answer 4

Satiety center

Question 5

What is the role of the Arcuate nucleus?

Answer 5

Regulation of appetitie

Question 6

What is the role of the lateral hypothalamus?

Answer 6

Hunger center

Question 7

What is the role of the anterior hypothalamus?

Answer 7

Thermoregulation

-cooling center and reg of thirst

Question 8

What is the role of the posterior hypothalamus?

Answer 8

Thermoregulation

Heating center

Question 9

What is the mode of transmission of the different cell types?
Gap junctions
Synaptic 
Paracrine
Endocrine

Answer 9

GJ: Directly from cell to cell(local) (anatomic location)

Syn: Across synaptic cleft (anatomic location and receptors)

Para: By diffusion in interstitial fluid (locally diffuse)(receptors)

Endo: By circulating body fluids (general)(receptors)

Question 10

What is the Second messenger pathway used in peptide hormones?

Answer 10

IP3 and DAG

Phospholipase C

Question 11

What is the second messenger pathway used by Lipid Soluble hormones?

Answer 11

Diffusion through membrane Intracellular receptor and translocation to the nucleus
Nuclear receptor
Acts on DNA

Question 12

What is the endocrine axis negative feedback pathway?

Answer 12

Hypothalmic neuroendo neurons
Releasing hormone
Pituitary gland
Tropic Hormone
Peripheral Endo Gland
Hormone (fd-bk to Pit and Hypth)
Target organ
Physiological effects

Question 13

What is te physiological response driven neg feedback pathway?

Answer 13

Endocrine gland
Hormone
Target organ
Phys effects
Circulating component (neg feedback to endo gland)

Question 14

What hormones are made and released by the Anterior Pituitary?

Answer 14

Thyroid SH
ACTH
Follacle SH
Lutenizing H
Prolactin
GrowthH
IGFs

Question 15

What cell types secrete the different Ant Pit Hormones?

Answer 15

Somatotrope- GH
Lactotrope- Prolactin
Corticotrope- ACTH
Thyrotrope- TSH
Gonadotrope- FSH, LH

Question 16

What controls the secretion of aldosterone

Answer 16

Angiotensin II

Question 17

What Hormones are secreted by the Posterior Pituitary?

Answer 17

Vasopressin and Oxytocin

Question 18

What are the hormonal effects when 21 hydroxylase is inactivated?

Answer 18

Aldosterone and Cortisol decrease

Androstenedione is increased

Question 19

What are the hormonal effects when 17 hydroxylase is inactivated?

Answer 19

Zero Cortisol and Androstenedione

Increased Aldosterone

Question 20

What are the effects of T3 and T4 on on TRH and TSH?

Answer 20

T3 and T4 have a negative feedbak effect on TRH(Hyp) and TSH(AP)

Question 21

What are the hormones involed in the HPL axis?

Answer 21

ALS(acid labile subunit)
GHBP(binding)
GHRH(releasing)
IGFBP(Insulin like growth factor binding protein)
IGF-1

Question 22

What is the role of prolactin?

Answer 22

Prepares the female breast to secrete milk (doesn’t cause milk secretion itself)

Question 23

What is the role of vasopressin?

Answer 23

Causes Aquaporin production

Question 24

What are the causes of Diabetes insipidus?

Answer 24

Central(tumor, trauma, surgery)

Nephrogenic(renal dis, ADH unresponsive kidney)
Drugs(lithium)

Question 25

How is Diabetes insipidus diagnosed?

Answer 25

Restrict H20, measure urine osmolality

Give ADH and measure response(no response, unresponsive kidney)