Physiology: The Adrenal Medulla Flashcards
Which nervous system regulates the adrenal medulla?
The sympathetic nervous system
Name three hormones produced by the adrenal medulla.
Adrenaline
Noradrenaline
Dopamine
What are the hormones produced by the adrenal medulla generally called?
Catecholamines
Name the three regions of the adrenal gland as well as what they secrete
Zona glomerulosa- aldosterone
Zona fasciculata- Glococorticoids
Zona reticularis- sex hormones
Name the enzyme that is important for the synthesis of catecholamines
L-Aromatic amino acid decarboxylase
True or false:
Adrenal medulla is a modified sympathetic ganglion
True
Which adrenoreceptor does noradrenaline responds strongly with?
Alpha receptor
What are the effects of noradrenaline?(2)
Mydriasis( pupil dilation) , glycolysis, lipolysis and vasoconstriction.
To which adrenoreceptors does adrenaline has greater affinity to?
Beta receptors
What are the effects of adrenaline?(2,5)
-Arteriole dilation of skeletal vasculature.
- Bronchial muscle relaxation
- Positive inotropy and chronotropy.
- Glycolysis
- Lipolysis
What hormone increases the likelihood of catecholamine release?
Thyroxine
Give the relevant characteistics of alpha-1 receptor
•It is found in most sympathetic target tissues.
• It is mostly sensitive to Noradrenaline.
• It activates phospholipase C.
Give the relevant characteistics of alpha-2 receptor
•It is found in the GIT and pancreas.
•It has greater sensitivity for Noradrenaline.
• It decreases cAMP.
Give the relevant characteistics of beta-1 receptor
•It is found in the heart muscles, kidney.
• It has equal sensitivity for both adrenaline and noradrenaline.
• It increases cAMP.
Give the relevant characteistics of beta-2 receptor
• It is found in certain blood vessels and smooth muscles of certain organs.
• The sensitivity of adrenaline is greater than that of noradrenaline.
• It decreases cAMP.