thyroid and adrenal hormones

Question 1

histology of adrenal cortex
1) zona glomerculosa
2) zona fasciculata
3) zona reticularis

Answer 1

1) cluster of small cells, aldosterone regulated by angiotensin 11
2) large cells arranged in cords. cortisol regulated by ACTH
3) smaller cells. adrenal androgens regulated by ACTH

Question 2

-key role of cortisol (catabolic hormone)
-regulation of cortisol secretion

Answer 2

-maintence of blood glucose for brain during fasting
and stimulates glucongenesis in liver, proteoliis and lipolysis. -stimulates calcium excretion and surpresses immune systum

-regulated by hypothalamic - pituitary- adrenal axis .hypothalamus releases corticotrophin releasing hormone (CRH) which stimulates (ACTH).
-circadium rhyrthms
-physical and emotional stress

Question 3

therapeutic use of cortisol
-corticosteroid drugs made up of
-examples of replacement cortisol
-examples of anti-inflammatory and immunosuppresent cortisol

Answer 3

-made of a mixture of glucocorticoids (cortisol) and mineralcorticoids (aldosterone)

-adrenal insufficiency (addisons disease)

-asthma, eczema, inflammatory bowel disease

Question 4

what are thryoid hormones synthesised from?
where are T3 and T4 hormone synthesied and stored?

Answer 4

-tyrosine and iodine
stored on thyroglobulin in thyroid hormones

Question 5

how do you get iodine in the diet

Answer 5

foundin fish, dairy products, seaweed

Question 6

mechanism of action for T3 and T4 thyroid hormone

Answer 6

T4 is converted into T3 peripherally and acts via nuclear receptors.
-thyroid hormone has effects in all body tissues

Question 7

thryoid hormone regulation by hypothalamic pituitary thyroid axis

Answer 7

hypothalamus secretes thyrotropin releasing hormone (TRH),
which stimulates thyroid stimulating hormone (TSH) from pituitary which increases secretion of T3 and T4.

TSH and TRH production are inhibited by T3 and T4 (negative feedback)

Question 8

what is congenital hypothyroidism and effects

Answer 8

inadequate thyroid hormone production in newborn. due to
under developed thyroid gland

effects= short, delayed bone growth, puberty

Question 9

in neonatal bloodspot test what level of TSH could suggest hypothyroidism due to underdeveloped thyroid gland

Answer 9

TSH is high suggests thyroid gland is not responding to stimulus

Question 10

why someone on long term steroids can’t get correct corisol response when faced with an illness?

Answer 10

due to negative feedback systum of cortisol on hypothermic pituitary axis means no stimulus on adrenal gland to produce cortisol

Question 11

in throid gland, what stores the precurser for thryoid hormone synthesis?

Answer 11

colloid within thryoid follicles