Metabolic rate, growth and disease Flashcards

1
Q

Growth hormone effects

A

Children: deficiency- dwarfism excess-gigantism
Adults: deficiency- no obvious disease excess= acromegaly

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2
Q

Growth hormone regulation

A

Hypothalamus
GHRH increases and somatostatin suppresses secretion from anterior pituitary
Target organs release IGFs to provide feedback inhibition

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3
Q

GH action

A

acts via tyrosine kinase associated receptor –> protein phosphorylation–> diabetogenic effects- liver increases gluconeogenesis, increase lipolysis, muscles- decrease glucose uptake (more for brain)

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4
Q

What stimulates GHRH

A

low glucose

amino acids, TRH and ghrelin

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5
Q

Thyroid Hormones

A

T3 (1 tyrosine) and T4 production and release stimulated by TSH.
rT3= inactive
T4–> T3= 2 enzymes (type 1- in liver/kidney/ thyroid type 2- in pituitary/CNS/ placenta)

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6
Q

Thyroid hormone effects

A

increase gluconeogenesis, glycogenesis , increase lipolysis, proteolysis increase Na/K/ATPase activity
Chronic: infants–> dwarfism and cretinism later childhood-impairment of growth

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7
Q

Glucocorticoids

A

hypothalamus integrates stress factors and diurnal rhythms to release CRH–> induces ACTH release from ant pituitary –> stimulates adrenal cortex –> hypertrophy and cortisol release
act via nuclear receptor to induce gene transcription

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8
Q

Glucocorticoids acute effects

A

inhibit insulin responses and enhance SNS responses –> target glucose to brain and other organs use fats
in liver promotes gluconeogenesis and glucose release
In fat: lipolysis
Min muscle: protein breakdown for FFA

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9
Q

Glucocorticoids chronic effects

A

immunosupression, reduced inflammation, stimulate haematopoiesis, fat redistribution to centre, skin thinning, muscle wasting, osteoporosis
excess–> cushings
insufficiency –> Addison’s disease

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