Endocrine Control Of Growth And Development Flashcards Preview

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Flashcards in Endocrine Control Of Growth And Development Deck (38):
1

What are somatomedians

Insulin like growth hormones - IGF's
Prod in somatotrophs and cause sec of GH

2

What are the thyroid hormones

T3 - triiodothyronine
T4 - tetrauidothyroinine

3

What does calcitonin, vit d and PTH all functionally have in common

They help regulate the calcium balance in the body

4

What are oestrogens and testosterone important for

Imp for the development of secondary sexual differentiations

5

Explain GH secretion

In daily bursts not continuous
Initiated by GHRH
Secretion terminated by somatostatin

6

Where is GHRH and somatostatin produced

The hypothalamus

7

What is diurnal rhythm

Sleep/wake pattern
Peak sec highest in morning and decreases though the day

8

What happens if GH is injected to a hypophysectomised animal

Stimulation of bone growth
Stim of protein syn
Stim RBC prod
Anti insulin effect - increase hepatic glucose, promote lipolysis and decreased glucose uptake

9

What are the effects of GH

Growth by increasing protein syn in tissues it increase num and size of cells
In bone it promotes IGF1 which bone growth at epiphyseal plates before close off

Has metabolic actions
- increase net syn of protein
- decreases glucose uptake
- increase lipolysis

10

What are the stimulants for GH secretion

Deficiency of energy substrate
Hypoglycaemia
Exercise and fasting
Increases in blood amino acids arg or leu
Glucagon
Stress
Deep sleep

11

What are the inhabitants of GH

Rapid eye movement sleep
Hyperglycaemia
Cortisol
Free fatty acids
GH
Hypothyroidism
Ageing

12

What does GH do to carbohydrates

Increases blood glucose
Decreases peripheral insulin sensitivity
Increases hepatic glucose output

13

What does GH do to proteins

Increase the tissue amino acid uptake
Increase incorporation into proteins
Decrease urea production

14

What does gh do to lipids

Lipolysis - activates hormone sensitive lipase (ligase stimulated by adrenaline and GH) yield FA's

15

What does GH do to IGF's

Stimulates production of IGF's
Stimulates growth
Is mitigenic ( stim grow in soft tissues)

16

What produces IGF-1

The liver

17

What causes the production of IGF-1

The sce of GH

18

What does IGF-1 do

Stimulate the bone growth and cell proliferation leading to soft tissue growth

19

What can sometimes happening dwarfism

That GH is norm,a but IGF-1 hormone subnormal

20

What happens when there is an adenoma in the anterior pituitary in children and adults

Children - leads to gigantism - excess GH to epiphyseal plates deal - long bone prod

Adult - acromegaly - thickening of bones coarsened facial features and thickend fingers hands and feet

21

What 3 hormones does the thyroid gland produces

Triiodothyronine
Tetraiodothyronine
Calcitonin

22

What mech regs t3/t4

Negative feedback loop

23

How are t3 and t4 ttansported in the blood

Bound to thyroxine- binding globulin plasma protein (TBG)

24

What is the structure of the thyroid gland

Follicular cells - spheres on the outer layer

Filled with colloid - extracellular storage for th
Tyrosine containing thyroglobulin filed spheres enclosed by follicular cells

25

What is required for new thyroid hormones and how are they obtained

Iodine and tyrosine and taken up by follicle cells

26

How are new thyroid hormones prod

Iodine and tyrosine taken up
In colloid iodine attach to tyrosine residue to form MIT and DIT
If DIT+DIT= T4 Or. DIT+ MIT = T3

Sited in colloid until needed

27

What does t3 and t4 do

Promote accelerate metabolism
Increase carbohydrate fat and protein turnover
Increase oxygen consumption and increased heat production


Imp during Dev if hypothyroidism in child = CRETIN

28

What is sympathomimetic action

Increases responsiveness to catecholamines adrenaline and noradrenaline by increasing number of adrenal receptors

29

What is hyperthyroidism

Lead to heat intolerance
Nervousness
Insomnia
Weight loss
High nitrogen exertion

30

What is hypothyroidism

Lead to cold intol
Excess sleep
Muscular fatigue
Weight gain

31

What is the basal metabolic rate

Amount of energy con husked during a testing individual so energy r reunited to just be in living state (energy for brain activity, pump blood and cellular processes)

32

What is the primary regulatory hormone of BMR

Thyroid hormone

33

What is the condition hypothyroidism in adults

Myoxedema

34

What is goitre

Swell of thyroid gland
Iodine deficiency - red t3/t4 promote excessive TSH secretion a nd growth of thyroid
Graves' disease - TSI promote thyroid growth
Excess TSH form ant pit

35

What is when there is no goitre

Hypothyroidism secondary to hypothalamus or ant pit failure (thyroid is not excessively stimulated)
Overactive thyroid TSH suppressed by excessive t3/4

36

What are testosterones actions

In fetal Dev imp for reproductive organs
During puberty stim bone growth and SECINDARY sexual characteristic

37

What does estradiol

Oestrogen
Stimulates growth of uterus
Imp for follicular growth
Stim bone growth
Delay bone loss during menopause

38

Where is GH prod

Anterior pituitary