Adrenocortical function and dysfunction Flashcards Preview

Gabe's Endocrinology > Adrenocortical function and dysfunction > Flashcards

Flashcards in Adrenocortical function and dysfunction Deck (78)
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61

What is the embryological origin of the adrenal medulla?

Modified part of SNS

62

What happens in the adrenal medulla?

Modified postganglionic sympathetic neurons (chromaffin cells) secrete neurohormones (catecholamines).

63

What are the 3 catecholamines?

  • Adrenaline (only made in adrenal medulla)
  • Noradrenaline
  • Dopamine

64

What are secretions from the adrenal medulla stimulated by?

Preganglionic sympathetic neurons.

65

What is the precursor to dopamine?

DOPA

66

What converts tyrosine to DOPA?

Tyrosine hydroxylase

67

What converts DOPA to dopamine?

Amino acid decarboxylase

68

What converts dopamine to noradrenaline?

Dopamine-beta-hydroxylase

69

What converts noradrenaline into adrenaline?

PNMT

70

Where is PNMT found outside of the CNS?

In the adrenal medulla

71

What are the adrenomedullary hormone actions on flight-or-fight responses?

↑cardiac rate and contractility, ↑TPR, ↑BP

72

What are the adrenomedullary hormone actions on metabolic effects?

↑glucose & FFA, ↑BMR

73

What are the adrenomedullary hormone actions on central effects?

↑arousal & alertness

74

What are the adrenomedullary hormone actions on stress responses?

  • Physical
  • Psychological

75

Have there been any recognised hyposecretion disorders of the adrenal medulla?

No

76

What is adrenomedullary hypersecretion disorder?

  • Pheochromocytomas (tumor)
  • Rare
  • Potentially deadly (hypertension)
  • Treatment: removal

77

What role does stress play in cortisol secretion?

  • Nonspecific stimuli (“stressors”) disrupt homeostasis
  • Two types of stress elicit two responses
    • Acute stress results in the fight‐or‐flight reaction
    • Chronic stress elevates cortisol levels, which suppresses immune responses

78

What is the MoA of stress on the hypothalamus?

See image.