Endo 3

Question 1

The bulk of the products created by the paraventricular nucleus is?

Answer 1

GHRH

SRIF-inhibiting factor

Question 2

GH/GHIH go to pituitary gland and act on somatotrope and release their products which go into circulation to have their effect where

Answer 2

Bone/muscle
Liver
-produces IGF-1 when stimulated by GH
-IGF-1 produces negative feedback effects of GH production- responsible for the decline in circulating GH

Question 3

GH uses which type of receptor?

Answer 3

Cytokine receptor

Question 4

IGF-1 uses which type of receptor/

Answer 4

Tyrosine kinase receptor

Question 5

GHRH and SRIF use which type of receptor

Answer 5

G-protein linked receptors

Question 6

IGF-1

Answer 6

systemic and autocrine effects
low neonatally, high at puberty, lower later in life
needed for skeletal and extra-skeletal development, adipocyte differentiation

Question 7

IGF-2

Answer 7

prominent during embryonic/fetal growth, with insulin

Question 8

GH secretion patterns

Answer 8

• rate of secretion of GH decreases after adolescence
• Levels fluctuate with the time of day (22hr-0200hr)
• Secretion regulated by GHRH and GHIH
• In older animal GH and IGF remain essential regulators of tissue renewal and metabolism

Question 9

How is the majority of GH found?

Answer 9

Bound to binding protein GHBP

some can be trasported as a free hormone

Question 10

How is IGF-1 found

Answer 10

almost entirely bound to transport proteins

-some IGF-1 transport/binding proteins have an endocrine function

Question 11

Factors affecting GH secretion include

Answer 11

sleep- increase
exercise- increase
hypoglycemia-increase
hyperglycemia- decrease
high dietary protein- increase
steroids-increase
glucocorticoids- decrease
endocrine disruptors -decrease
ghrelin -increase

Question 12

What is the function of GH and IGF-2 in the fetus/neonate

Answer 12

act together on the growth plate of long bones in young animals
GH promotes growth of cartilage while IGF-2 promotes the ossification (calcification) of cartilage cells

Question 13

Function of GH and IGF-1 on:
Hepatic glucose release
Plasma glucose concentration
Sensitivity of tissue to insulin
Lipolysis in adipocytes

Answer 13

GH: In, In, Dec, In

IGF-1: Dec, Dec, In, Dec

Question 14

GH is a _________ factor that opposed the actions of insulin and IGF-1 on ____ and ____ homeostasis

Answer 14

diabetogenic

carbs and lipid

Question 15

Other physiological roles of GH

Answer 15

Contributes to the maintenance and function of pancreatic islets
Stimulates the immune system
Anti-aging effects
Stimulates the growth and regeneration of internal organs except for the brain
Normal reproduction

Question 16

In which country are hormonal growth promoters banned?

Answer 16

European union

Question 17

What are the problems associated with GH use

Answer 17

• increased stress of animal associated with high milk production and increased risk of mastitis
• adverse effects on reproduction: cystic ovaries, uterine disorders, decreased gestation length

Question 18

Dwarfism

Answer 18

• deficiency of anterior pituitary hormones during childhood
• specifically due to deficiency of GH
• parts of body develop in proportion to eachother

Question 19

Pygmy

Answer 19

african pygmy
-normal levels of GH
-hereditary inability to form somatomedin
Laron-type dwarfism 
-decreased responsiveness to GH and IGF

Question 20

Gigantism

Answer 20

cells of pituitary become active due to following reasons and produce excess GH
-hyperplasia
-tumor
If over production occurs before epiphyses of long bones fused with shafts then bone will continue to grwo
-hyperglycemia - 10% have diabetes mellitus

Question 21

Acromeagaly

Answer 21

tumor occuring after epiphysis has fused
soft tissue can grow and bone grows in thickness
results in enlarged hands and feet, membranous bones in cranium
enlarged organs: tongue, liver, kidney