3_Pituitary

Question 1

From where is the anterior pituitary derived?

Answer 1

Rathke’s Pouch as an epithelial invagination of the pharynx

Question 2

What hormone do somatotropes secrete?

Answer 2

GH

Question 3

What hormone do corticotropes secrete?

Answer 3

ACTH

Question 4

What hormone do thryotropes secrete?

Answer 4

TSH

Question 5

What hormone do gonadotropes secrete?

Answer 5

FSH/LH

Question 6

What hormone do lactotropes secrete?

Answer 6

PRL

Question 7

What kinds of hormones does the anterior pituitary secrete?

Answer 7

peptide

Question 8

What are the most prevalent 3 hormones secreted by the anterior pituitary?

Answer 8

1) GH (30-40%), 2) ACTH (20%), 3) TSH (3-5%)

Question 9

How is the anterior pituitary under neural control?

Answer 9

parvicellular neurons secrete releasing factors into the median eminence

Question 10

From where is the posterior pituitary derived?

Answer 10

neural hypothalamic outgrowth – glial cells

Question 11

From where are hormones released in the posterior pituitary?

Answer 11

from magnocellular neurons in the PVN & SON

Question 12

How do the anterior & posterior pituitary blood supplies differ?

Answer 12

anterior: portal; posterior: independent

Question 13

What kinds of hormones does the posterior pituitary secrete?

Answer 13

2 peptide hormoens

Question 14

Neurons with THIS ORIGIN secrete ADH.

Answer 14

SON

Question 15

Neurons with THIS ORIGIN secrete oxytocin.

Answer 15

PVN

Question 16

How is oxytocin release stimulated?

Answer 16

suckling

Question 17

What are the effects of oxytocin?

Answer 17

uterine contractions & milk expression

Question 18

What releasing factors does the hypothalamus secrete?

Answer 18

TRH, GnRH, CRH, GHRH, somatostatin, PIH/dopamine

Question 19

What are the characteristics of HT releasing factors in terms of secretion and action?

Answer 19

pulsatile secretion due to neural origin; affect specific GPCRs in the anterior pituitary

Question 20

To what hormones is GH ancestrally related?

Answer 20

hCS & PRL

Question 21

Describe the structure of GH.

Answer 21

191 AA with 2 S-S bridges

Question 22

Describe the half-life of GH.

Answer 22

20 minutes

Question 23

What things increase GH secretion?

Answer 23

GHRH, hypoglycemia, ghrelin

Question 24

What things decrease GH release?

Answer 24

somatostatin, GH, IGFs, hyperglycemia

Question 25

What things increase PRL secretion?

Answer 25

suckling, TRH, PRFs

Question 26

What things decrease PRL secretion?

Answer 26

dopamine/PIH

Question 27

What is the primary effect of GH?

Answer 27

gluconeogenesis

Question 28

Where are IGFs produced?

Answer 28

liver

Question 29

Describe the secretion pattern of GH.

Answer 29

circadian rhythm = 5 pulses per day, greates during sleep. Highest levels at puberty, lowest in elderly years.

Question 30

Describe the signaling pathway for the GH receptor.

Answer 30

RTK via JAK-STAT pathway

Question 31

What is the transcription factor produced by the JAK-STAT pathway?

Answer 31

2 STAT-P

Question 32

What are the negative feedback pathways on GH?

Answer 32

IGFs and glucose, both inhibitory

Question 33

What are the metabolic effects of GH?

Answer 33

adipose: increased lipolysis; liver: IGFs & gluconeogenesis; muscle: increased protein synthesis

Question 34

What are the effects of IGFs?

Answer 34

somatic cell growth and increased chondrocyte function

Question 35

What is the other name for IGF-1?

Answer 35

somatomedin C

Question 36

What is the receptor for IGF-1?

Answer 36

IGF1R1, an RTK; also 6 others and the insulin receptor

Question 37

Why does IGF-1 mainly cause the metabolic effects of GH?

Answer 37

longer half-life (binding proteins are stable)

Question 38

When is IGF-1 deficient?

Answer 38

pygmies

Question 39

What is the treatment for dwarfism/panhypopituitarism?

Answer 39

GH/hormone replacement

Question 40

What is the cause of dwarfism?

Answer 40

GH deficiency during childhood

Question 41

What is the manifestation for panhypopituitarism?

Answer 41

congenital or acquired

Question 42

What is Sheehan's Syndrome?

Answer 42

postpartum hypopituitarism

Question 43

What causes Sheehan's syndrome?

Answer 43

lactotroph hyperplasia during pregnancy = enlargement = ischemia after blood loss during delivery

Question 44

What generally causes hyperpituitarism?

Answer 44

an acidophilic (somatotrophic) cell tumor

Question 45

When does hyperpituitarism cause gigantism?

Answer 45

if hyperpituitarism prior to epiphysis fusion (pre-pubertal)

Question 46

When does hyperpituitarism cause acromegaly?

Answer 46

if hyperpituitarism after epiphysis fusion (post-pubertal)

Question 47

What is the treatment for gigantism?

Answer 47

surgery and/or irradiation

Question 48

What is the treatment for acromegaly?

Answer 48

surgery, GHIH, GH antagonists

Question 49

What are the complications of gigantism?

Answer 49

T2DM and hypopituitarism

Question 50

What are the signs of acromegaly?

Answer 50

thickening of long bones, growth of soft tissue, membranous bones leading to kyphosis

Question 51

What are the complications of acromegaly?

Answer 51

heart disease, T2DM, sleep apnea, arthritis, sweating