endocrine disorders

Question 1

adrenal glands structure

Answer 1

• capsule
• zona glomerulosa
• zona fasciculata
• zona reticularis
• adrenal medulla

Question 2

hormones secreted by adrenal glands

Answer 2

adrenocorticoids
mineralocorticoids
glucocorticoids

Question 3

adrenocorticoids

Answer 3

naturally occurring compounds secreted by the adrenal cortex

Question 4

mineralocorticoids

Answer 4

• primarily aldosterone
• zona glomerulosa
• Na+ reabsorption and K+ excretion in kidneys

Question 5

glucocorticoids

Answer 5

• primarily cortisol
• zona fasciculata
• regulate the body’s response to stress

Question 6

sex hormones

Answer 6

• primarily androgens
• zona reticularis
• regulate reproductive function

Question 7

adrenal medulla

Answer 7

• secretes catecholamines
• 80% adrenaline (epinephrine)
• 20% noradrenaline (norepinephrine)

Question 8

cortisol secretion

Answer 8

• hypothalamus secretes corticrophin-releasing hormone (CRH)
• anterior pituitary senses hormone and responds by secreting adrenocorticotrophic hormone (ACTH)
• ACTH travels to adrenal cortex and acts on cells and stimulates secretion of cortisol

Question 9

cellular actions of cortisol

Answer 9

• main glucocorticoid
• receptors for cortisol found in many tissues
• increases circulating glucose level
• maintain the normal responsiveness of blood vessels to vasoconstrictive stimuli
• effects on immune system, nervous system, kidneys
• pharmacological actions (anti-inflammatory, immunosuppressant)

Question 10

increase in cortisol actions

Answer 10

• glucose uptake decreases
• amino acid uptake decreases
  adipose tissues:
• increased lipolysis
  muscle tissues:
• increased protein breakdown
• decreased protein synthesis
  liver:
• increased gluconeogenesis

Question 11

addison’s disease

Answer 11

• primary adrenocortical insufficiency
• due to destruction or dysfunction of the entire adrenal cortex
• affects both glucocorticoid and mineralocorticoid function
• onset of disease occurs when 90% or more of both adrenal cortices are destroyed

Question 12

symptoms of addison’s disease

Answer 12

• darkening areas of the skin (hyperpigmentation)
• extreme fatigue
• unintentional weight loss/decreased appetite
• low blood pressure
• gastrointestinal disturbance (nausea, vomiting, abdominal pain)
• salt craving
• low blood glucose (hypoglycaemia)

Question 13

treatment of addison’s disease

Answer 13

• hydrocortisone (sometimes prednisolone)
• fludrocortisone (mineralocorticoid)
• daily adult dose of hydrocortisone is 15-30mg
• given as a divided dose (10mg on waking, 5mg at noon and 5mg in early evening)
• treatment is lifelong

Question 14

secondary adrenal insufficiency

Answer 14

• lack of ACTH secretion from pituitary
• lack of corticotrophin releasing hormone secretion from hypothalamus
• can also be due to glucocorticoid drug therapy
• can occur if glucocorticoid medication is stopped too abruptly
• treatment with glucocorticoid (hydrocortisone) but mineralocorticoid is unnecessary