Hypothalamus + GH

Question 1

list the cAMP signaling pathway hormones

Answer 1

G-FLAT ChAMP

• GHRH (somatostatin decreases cAMP levels)
• FSH
• LH
• ACTH
• TSH
• CRH
• hCG
• ADH (V2, collecting ducts)
• MSH
• PTH

Question 2

list the IP3 signaling pathway hormones

Answer 2

GOAT HAG

• GnRH
• Oxytocin
• ADH (V1, blood vessels)
• TRH
• Histamine
• AGII
• Gastrin

Question 3

list the intracellular signaling pathway hormones

Answer 3

PET CAT on TV

• Progesterone
• Estrogen
• Testosterone
• Cortisol
• Aldosterone
• T3/T4
• Vitamin D

Question 4

the pituitary stalk passes through ____ as it connects to the hypothalamus

Answer 4

sellae

Question 5

the ____ artery supplies the ____ forming the primary capillary plexus

Answer 5

superior hypophyseal artery

median eminence

Question 6

name the 4 releasing hormones and 2 inhibiting hormones

Answer 6

• Releasing hormones
  
  • CRH
  • GnRH
  • TRH
  • GHRH
• inhibiting hormones
  
  • dopamine (prolactin)
  • somatostatin

Question 7

contrast magnocellular and parvocellular

Answer 7

• magnocellular neurons transport ocytocin (PVN) and ADH (SON) via axon transport
• The axons of the parvocellular neurosecretory neurons of the PVN project to the median eminence where their neurosecretory nerve terminals release their hormones at the primary capillary plexus of the hypophyseal portal system.

Question 8

name the cells in the posterolateral area of the anterior pituitary. Why is this area important?

Answer 8

• gonadotrophs
• somatotrophs

Posterolateral cells are the 1st to be affected by mechanical lesions

Question 9

name the cells in the anteromedial area of the AP. Why is this area important?

Answer 9

• corticotrophs
• thyrotrophs

This area is the most protected and resilient

Question 10

where are lactotrophs located in the AP?

Answer 10

• they are scattered throughout the gland

Question 11

all hormones except for ____ and ____ function by stimulating other endocrine glands

Answer 11

GH and Prolactin

Question 12

name the 3 classes of AP hormones

Answer 12

• glycoproteins
  
  • TSH, FSH, LH
  • alpha chains identical
  • B chains differ (confers biological properties)
• POMC -> ACTH
• lactogens
  
  • GH, prolactin
  • similar in structure

Question 13

what are 2 ways in which GH is released

Answer 13

• GHRH from the hypothalamus increases GH production
• hypoglycemia -> ghrelin -> GH release from AP

Question 14

describe signaling pathway of GH

Answer 14

Think Growth Factors

Tyrosine = GF

Question 15

describe the pulsatile secretion of GH

Answer 15

• occurs in periodic bursts, with maximal peaks at night (usually stage 3/4 of sleep)
  
  • sleep helps adolescents grow

Question 16

describe GH actions in liver

Answer 16

• liver: increase glucose synthesis an increase blood glucose and increase synthesis of IGF-1 (somatomedin C)

Question 17

describe GH action in adipose tissue

Answer 17

• adipose: increase lipid breakdown and increase free fatty acids and glycerol
  
  • decrease glucose uptake, which increases blood glucose

Question 18

describe GH action in muscle tissue

Answer 18

• muscle: increase amino acid uptake, which increases protein synthesis. decreases glucose uptake which increases the amount of glucose in blood

Question 19

describe effects of IGF

Answer 19

• important for growth-promoting effects of GH
• promote linear bone growth
• increase organ size and function
• negative feedback on GH
• insufficient synthesis of IGF can result in dwarfism
  
  • African pygmies and Laron syndrome

Question 20

describe hypersecretion of GH

Answer 20

• before closure of epiphyseal plates = gigantism
• after closure of epiphyseal plates = acromegaly
  
  • frontal bossing
  • prominent chin
  • growth of mandible (prognathism)
  • enlargement of hands, feet, ears, nose