Endocrine control of growth

Question 1

3 types of growth

Answer 1

normal, catch-up, compensatory

Question 2

Phases of normal growth

Answer 2

fetal (rapid), postnatal, pubertal, adulthood, senscent (may be a decline)

Question 3

What is required for normal growth?

Answer 3

proper nutrition, sufficient hormones, good psychosocial enviornment

Question 4

Hormones involved in prenatal growth which grows to 30% of adult growth?

Answer 4

insulin, hpL

Question 5

Hormones involved in infantile growth which lasts 0-1 years

Answer 5

insulin

Question 6

Hormones involved in junvenile growth which lasts 1-12 years and 85-88% of adult height

Answer 6

insulin, hGH, T3, VD

Question 7

Hormones involved in adolescent growth

Answer 7

insulin, hGH, T3, sex steroids, VD

Question 8

What does excess GH cause?

Answer 8

increase linear growth, normal skeletal maturation, but an increased affect on adult stature. Gigantism, increase to genetic potential?

Question 9

What does deficiency in GH cause?

Answer 9

decrease linear growth, delayed skeletal maturation, increase dwarfism (hyposomatotropic dwarfism)

Question 10

What does excess TH cause?

Answer 10

slight increase in linear growth, slight advance in skeletal maturation, minimal effect on adult stature

Question 11

What does TH deficiency cause

Answer 11

decrease linear growth, delayed skeletal maturation, negative affect of adult stature

Question 12

What does cortisol excess cause?

Answer 12

decreased linear growth, delayed skeletal maturation, negative affect on skeletal maturation

Question 13

What does androgen excess cause?

Answer 13

increase followed be decrease in linear growth, advanced in skeletal maturation, negative effect on adult stature

Question 14

What does androgen deficiency cause?

Answer 14

increase linear growth, delayed skeletal maturation, eunuchoidal (tall with long arms and legs)

Question 15

What does rx with low dose estrogen cause?

Answer 15

increase linear growth, normal skeletal maturation, normal adult stature

Question 16

What does rx with excess/moderate dose estrogen cause?

Answer 16

increase linear growth than decrease, advanced skeletal maturation, decreased adult stature

Question 17

What does estrogen deficiency cause?

Answer 17

increase in linear growth, delayed skeletal maturation, increased adult stature

Question 18

What is somatotropin?

Answer 18

GH

Question 19

What is somatomedin?

Answer 19

SM-C/ IGF-1–> mediates some of GH actions on bone elongation and adipocytes

Question 20

What is somatostatin?

Answer 20

hypothalamic peptide that inhibits GH secretion

Question 21

What is somatocrinin?

Answer 21

hypothalamic peptide that stimulates GH secreation (GHRH)

Question 22

What are the 2 structural forms of GH and what is the difference?

Answer 22

22K: 90% of GH, growth promoting + other metabolic actions
20K: 10% of total GH and mainly growth-promoting

Question 23

What does isolated GH deficiency?

Answer 23

hyposomatotropic dwarfism

Question 24

When does GH exert its major action on body mass?

Answer 24

juvenile and pubertal periods

Question 25

When does GH exert its major action on tallness?

Answer 25

juvenile and pubertal periods only, synergism with then antagonism by gonadal steroids

Question 26

Where does GH exert its major action on long bone growth?

Answer 26

epiphyseal growth plate

Question 27

Secretory pattern of GH

Answer 27

episodic, ultraradian

Question 28

Physiological causes of increase GH

Answer 28

GHRH, decreased SS, spontaneous, deep sleep, exercise, acute stress, thyroid hormone, puberty, post-prandial decrease in glucose

Question 29

Physiological causes of decrease GH

Answer 29

SS, decreased GHRH, spontaneous, light sleep and waking, elevated GH, IGF1, aging, postprandial hyperglycemia, increased FFA

Question 30

Pharm. path, provocative causes of increased GH

Answer 30

GHRH, estrogens, hypoglycemia/ insulin, Arg/Leu, starvation, pituitary tumor

Question 31

Pharm/path/provocative causes of decreased GH

Answer 31

SS analogs, GC, hyperglycemia, hypothyroidism, hyperthyroidism, pituitary tumor, progesterone