Normal Growth and clinical aspects

Question 1

7 major factors that regulate growth

Answer 1

GH (from ant pituitary)

thyroid hormones

insulin

sex steroids

availability of nutrients

stress

genetics

Question 2

GH is a ……. hormone released from the ….. ……

Answer 2

peptide

anterior pituitary

Question 3

GH is also known as what?

Answer 3

somatrotopin

Question 4

GH release is controlled via the release of two hypothalamic neurohormones called:

Answer 4

Growth hormone Inhibiting hormone

Growth hormone releasing hormone

Question 5

What is the indirect action of GH?

Answer 5

growth and development

Question 6

what is the direct action of GH?

Answer 6

regulation of metabolism

Question 7

The first 8-10 months of life is largely controlled by ……………. ………., but thereafter GH becomes a dominant influence on the rate at which children grow

Answer 7

nutritional intake

Question 8

GH requires permissive action of ……… hormones and ………… before it will stimulate growth

Answer 8

thyroid

insulin

Question 9

The effect of GH on growth is almost entirely indirect, being achieved through the action of an intermediate known as

Answer 9

IGF-I

insulin like growth factor I

Question 10

what is IGF-I also known as?

Answer 10

somatomedin C

Question 11

What organ secretes IGF-I?

Answer 11

liver

Question 12

IGF-I is secreted in response to what??

Answer 12

GH release

through negative feedback loop

Question 13

GH and IGF-I are peptide hormones, but like steroid and thyroid hormones, they are transported in the blood bound to what?

Answer 13

carrier proteins

Question 14

IGF exhibits negative feedback on GH release. It does this by both via inhibiting …… and stimulating …….

Answer 14

GH

GHRH

GHIH

Question 15

IN BONES

GH stimulates chondrocyte precursor cells (prechondrocytes) in the ………. plates to differentiate into …………

Answer 15

epiphyseal

chondrocytes

Question 16

IGF-I acts as an autocrine or paracrine agent to stimulate the differentiating chondrocytes to undergo cell division and produce ………., the foundation for ……….. growth.

Answer 16

cartilage

bone

Question 17

Epiphyseal plates close during adolescence under the influence of …….. …………. ………… then no further longitudinal growth is possible.

Answer 17

sex steroid hormones

Question 18

GH Increases …………… by the liver.

Answer 18

gluconeogenesis

Question 19

GH Reduces the ability of …………. to stimulate glucose uptake by muscle and adipose tissue.

Answer 19

insulin

Question 20

GH Makes ……….. more sensitive to lipolytic stimuli

Answer 20

adipocytes

Question 21

GH Increases …. ……. uptake and protein synthesis in almost all cells = anabolic effect

Answer 21

amino acid

Question 22

4 main actions of GH

Answer 22

mobilises glucose stores to increase blood glucose

inhibits action of insulin

promotes lipolysis

promotes amino acid uptake to cells (supporting protein synthesis)

Question 23

majority of GH is released in the first …. …… of sleep

Answer 23

2 hours

Question 24

stimuli that increase GHRH secretion (5)

and therefore an increase in GH

Answer 24

decrease in energy supply to cells

increased AA (to help protein synthesis)

stressful stimuli (infection etc)

delta sleep increased

oestrogen and testosterone

Question 25

stimuli that increase GHIH secretion (5)

Answer 25

Glucose

FFA

REM sleep

cortisol

Question 26

name 6 hormones involved in growth

Answer 26

insulin

GH

IGF-1

thyroid hormones

sex steroids

glucocorticoids

Question 27

cretinism

Answer 27

children are hypothyroid from birth

retarded growth because of loss of TH’s permissive action on GH

Question 28

in cretinism their GH levels are……

Answer 28

normal

Question 29

2 periods of rapid growth in humans

Answer 29

puberty

infancy

Question 30

6 things that may cause dwarfism

Answer 30

GHRH deficiency

GH secreting cells are abnormal

end organ is unresponsive to GH

genetic mutations

precocious puberty

hypothyroid children

Question 31

Thyroid hormone effects are permissive to

Answer 31

GH

IGF-1