Somatic Growth

Question 1

two periods of rapid postnatal growth occur when

Answer 1

infancy (birth to 2 years)

late puberty

Question 2

important factors influencing birth size

Answer 2

genetic factors
the placenta
the maternal environment
hormones and growth factors

Question 3

what relationship is there between placenta and birth size

Answer 3

direct correlation b/w placental weight and birth weight

Question 4

infants born to women living at higher altitudes tend to be what compared to those born to women living at low altitudes

Answer 4

lower birth weight

Question 5

infants with varied forms of insulin resistance are what at birth (in terms of size)

Answer 5

very small

Question 6

infants born to diabetic mothers are what at birth (in terms of size)

Answer 6

high birth weight

Question 7

IGFs and IGFBPs have what role in fetal growth

Answer 7

essental role in stimulating fetal growth

Question 8

fetal IGF production (difference from adult IGF)

Answer 8

independent of GH stimulation

Question 9

IGF-1 levels at term are directly correlated to what

Answer 9

birth weight

Question 10

what happens to growth rate after birth

Answer 10

decelerates

Question 11

estimation of boys target height is done using what equation

Answer 11

((moms height+5 inches) + fathers height)/2

Question 12

estimation of girls target height is done using what equation

Answer 12

((fathers height-5 inches) + moms height)/2

Question 13

the principal extrinsic regulator of postnatal growth is

Answer 13

adequate nutrition

Question 14

for adequate nutrition particular importance must be made for what

Answer 14

dietary protein
essential vitamins and minerals
adequate caloric consumption

Question 15

major cause of short stature world-wide is

Answer 15

malnutrition

Question 16

what hormones have influence on growth prenatally

Answer 16

IGFs

insulin

Question 17

what hormone exclusively facilitates postnatal growth

Answer 17

sex steroids

Question 18

what is the most important hormone involved in promoting postnatal growth

Answer 18

GH

Question 19

IGF-1 levels peak when in life

Answer 19

pubertal growth spurt

Question 20

in the absence of GH thyroid hormones do what to growth

Answer 20

do not promote it

Question 21

in hypothyroid patients what are circulating levels of GH and IGF-1

Answer 21

both have low circulating levels

Question 22

GH secretion in response to provocative stimuli is diminished in patients with what

Answer 22

hypothyroidism

Question 23

treatment of hypothyroid with thyroxine does what to plasma GH and IGF-1 levels

Answer 23

both increase

Question 24

growth spurt at puberty accounts for how much of person stature and is due to what

Answer 24

15% of final stature

due to sex steroids

Question 25

sex steroids promote what (in terms of growth)

Answer 25

linear growth | maturation and fusion of the epiphyseal growth plate

Question 26

how do sex steroids increase growth velocity at puberty

Answer 26

stimulating growth hormone

Question 27

what is the principle hormone that stimulates increase in GH secretion

Answer 27

estradiol (for both males and females)

Question 28

what is the principle hormone responsible for stimulating growth plate maturation and fusion in both males and females

Answer 28

estradiol (E2)

Question 29

testosterone can be converted to estradiol via what enzyme

Answer 29

aromatase

Question 30

defective aromatase gene in boys (what happens)

Answer 30

no growth spurt

Question 31

androgens are what

Answer 31

potent anabolic steroids

Question 32

androgens promote what in males during puberty

Answer 32

promote marked increase in muscle mass

Question 33

testosterone is thought to do what to cortical bone

Answer 33

increase thickness via stimulating periosteal bone expansion

Question 34

insulin promotes what and inhibits what

Answer 34

promotes anabolism and inhibits protein catabolism

Question 35

what happens to proteins in absence of insulin

Answer 35

protein breakdown

Question 36

excessive amounts of glucocorticoids do what to normal growth

Answer 36

interfere- decrease proliferation of chondrocyte

Question 37

glucocorticoids are what type of agent

Answer 37

potent catabolic agents

Question 38

in a patient with excess glucocorticoids, removal of excess does what and to what extent

Answer 38

period of increased (catch-up) growth | usually not complete

Question 39

hypothalamic cause(s) of GH deficiency

Answer 39

GHRH deficiency

Question 40

target tissue cause(s) of GH deficiency

Answer 40

GH receptor deficiency | inability to produce IGF-1

Question 41

Laron Dwarfism (cased by what)

Answer 41

deletions or mutations of the gene for GH receptor (type 1)

Question 42

patients with Laron Dwarfism have what levels of circulating GH

Answer 42

high levels

Question 43

if a patients does not produce IGF in response to GH administration they may have what

Answer 43

laron dwarfism

Question 44

type 2 Laron Dwarfism (issue)

Answer 44

post GH receptor defects

Question 45

consequences of GH deficiency

Answer 45

dwarfism in children

Question 46

dwarfism (symptoms)

Answer 46

``` short stature delayed bone development delayed puberty mild obesity tendency toward hypoglycemia ```

Question 47

pituitary cause(s) of GH deficiency

Answer 47

somatotrope destruction by a tumor production of a defective GH molecule decreased GH production