Physiology: Hormonal Control of Growth

Question 1

What happens to growth in psychosocial deprivation?

Answer 1

Growth is stunted

Question 2

Why does psychosocial deprivation stunt growth?

Answer 2

Neural imputs to the hypothalamus!

Decreased GnRH, GH, TRH

Question 3

What do you give to stall puberty?

Answer 3

Long acting analog of GnRH, which down regulates GnRH receptors in pituitary. (Leupride) This can make them taller!

Question 4

What shuts down the epiphyseal plates after pubertal spurt?

Answer 4

Sex hormones: androgens and estrogens

Question 5

What hormones are required for normal somatic growth?

Answer 5

Insulin
Thyroid (thus TRH, TSH, iodine)
Cortisol (but not too much)
GI hormones
Vit D (and PTH)
Sex hormones
    -androgens (both)
    -estrogens (female)
IGF-1 (for GH in liver)
GH

Question 6

How tall are you when you are born, relative to adult height?

Answer 6

One third!

Question 7

What % of adult height as a infant? 1 year old? 10-12? Adolescent (10-14 f/12-16m)?

Answer 7

30%
50%
90%
100%

Question 8

Hormones in womb?

Answer 8

Insulin
IGF-1
hPL

Question 9

Hormones at 0- 1 year?

Answer 9

Insulin

IGF1

Question 10

Hormones at 1-12?

Answer 10

Insulin
GH
T3
Vit D

Question 11

Hormones at teen?

Answer 11

Insulin
GH
T3
Vit D
Sex hormones

Question 12

What does brain and head growth curve look like?

Answer 12

Tops out at 8 years

Question 13

What does organ growth curve look like?

Answer 13

Sigmoidal: 8 and teen spurt

Question 14

What do reproductive tissue growth curves look like?

Answer 14

4 fold in teen spurt

Question 15

What do lympoid tissue growth curves look like?

Answer 15

Spike at 10 years, slop to normal in late teens

*thymic effect of T and estrogen

Question 16

Growth hormone change height how much?

Answer 16

20-30%

Question 17

Lack of cortisol does what to growth?

Answer 17

Delays and decreases

Question 18

If a male has early onset androgens, what happens to adult height?

Answer 18

Shorter than normal

Question 19

What type of body does androgen deficiency cause in males?

Answer 19

Tall, long arms and legs, and round body.

Question 20

What happens if a girls has early onset estrogens?

Answer 20

Short stature

Question 21

What happens if a girl has decreased androgens?

Answer 21

Tall stature and slow growth

Question 22

What is another name for GH?

Answer 22

Somatotropin

Question 23

What is another name for IGF1?

Answer 23

Somatomedin

Question 24

What is another name for somatostatin?

Answer 24

SS, SRIH

Question 25

What is another name for GHRH?

Answer 25

Somatocrinin

Question 26

What are the effects of the 22k (90%) form of GH?

Answer 26

Growth

Metabolism increase

Question 27

What are the effects of the 20k (10%) form of GH?

Answer 27

Just Growth…

Question 28

How do you tell if a athlete has been taking GH?

Answer 28

The ratio of 22k/20k is greater than 9/10

Question 29

Is ingesting meat with GH a problem? Why? What about Estrogen? Why?

Answer 29

GH=Peptide=Digested in intestine

Estrogen=Steroid=Crosses barrier!

Question 30

What are the major actions of GH?

Answer 30

\+: Body mass
    tallness
    synergy with T3
    Bone growth
     bone thickening
     lypolysis

-: mildly impairs glucose uptake and utilization

+DNA, RNA, Ribosome, PS

Question 31

What is the - effects of GH?

Answer 31

-: mildly impairs glucose uptake and utilization (diabetogenic!)

Question 32

Is GH diabetogenic?

Answer 32

Yes

Question 33

TEST**What are the cellular effects of GH?

Answer 33

1. (Somatomedin hypthesis): GH->liver–>IGH1–>long bone and muscle growth
2. (Dual effector hypothesis): GH->everywhere–>different effects via IGF1 in those tissues

Question 34

GH leads to and increases of what in plasma?

Answer 34

IGF-1

IGF-1 binding protein

Question 35

What does IGF-1 do in the pituitary?

Answer 35

Inhibit?

Question 36

IGF1 and GH vary in what effects?

Answer 36

+ lypolysis, - insulin sensitivity: GH

-lypolysis, + insulin activity: IGF-1

Question 37

GH and IGF-1 break into what phases of growth?

Answer 37

GH: early, start differentiation

IGF-1: late, guide differentiation

Question 38

IGF-1 levels in acromegaly? Hypopituitary?

Answer 38

High, low

Question 39

Pygmies have what defect?

Answer 39

No GH receptor!

Question 40

If pt has GH insensitivity, what can you give them?

Answer 40

IGF-1… it helps somewhere downstream

Question 41

GH does what to K, Ca, Na, PO4?

Answer 41

Put them inside cells

Question 42

T3 with GH does what?

Answer 42

Increases GHRH

More effective GH

Question 43

GC do what to GH?

Answer 43

Inhibit

Question 44

Sum T3/GC?

Answer 44

+T3

-GC

Question 45

What is GC effect on growth?

Answer 45

GCs impair growth?

Question 46

GH absolutely needs what to act?

Answer 46

Insulin

Question 47

When is GH released?

Answer 47

Deep sleep

Question 48

When is cortisol released?

Answer 48

Mornin before waking

Question 49

What happens to GH over age?

Answer 49

Decreases to half and holds

Question 50

When is GH/IGF1 the highest?

Answer 50

WhatPuberty

Question 51

What increases GH?

Answer 51

GHRH
Decreased SS
Puberty
Deep sleep
Exercise
Acute stress
T3
Glucose decrease

Question 52

What causes GH to decrease?

Answer 52

SS
Decrease GHRH
Light sleep and waking
GH elevation
IGF1 elevation
aging
hyperglycemia
FFA increase

Question 53

What is needed for GH secretion?

Answer 53

T4/T3

Question 54

What stimulates GH in puberty?

Answer 54

T

Estrogen?

Question 55

Pituitary tumors do what to GH?

Answer 55

Can increase OR decrease

Question 56

What does sleep release of GH look like in psychosocial deprivation?

Answer 56

There is none! it returns with about 10 days, 1 month recovery

Question 57

TEST: Since GH is hard to get during sleep and expensive to test, what is a better test?

Answer 57

IGF-1