Adrenal gland Flashcards
Characteristics of adrenal gland
Weighs between 8-10 g
Sits above the kidneys
What is the function of the adrenal glands?
To help our bodies respond well to environmental changes
Can control many fight or flight responses in response to stress
What are the two areas of the adrenal gland?
Medulla
Cortex
What is the function of the medulla in the fight or flight response?
Dilation of airways
Improved gas exchange
Increase cardiac output
What is the funciton of the cortex in the fight or flight response?
Prevent losing extracellular fluid
Mental preparation -> if not able to mentally prepare = not able to cope
Suppress pain and inflammation
What do both the medulla and the cortex do in response to stress?
Keep blood glucose high
Characteristics of the arenal medulla
Made of chromaffin cells
Produces catecholamines
Extension of the sympathetic nervous system - nerves synapse with neuroendocrine cells in the medulla
What are chromaffin cells?
Neuroendocrine cells in the medulla
Synthesise and store epinephrine and norepinephrine
What are catecholamines?
Any structure with a catechol ring and an amine
What is a catechol ring?
Phenol ring with 2 OH
Process of catecholamine synthesis
- Main precursor = tyrosine
- Addition of -OH makes DOPA => catalysed by tyrosine hydroxylase
- DOPA -> dopamine by removing carboxyl group => catalysed by DOPA decarboxylase
- Dopamine -> norepinephrine by adding -OH => catalysed by dopamine oxidase
- Norephinephrine -> epinephrine by adding CH3
What is the main hormone in the adrenal medulla?
Epinephrine
What 3 layers make up the cortex?
Zona reticularis - inner
Zona fasciculata
Zona glomerulosa - outer
What are the differences between the layers that make up the adrenal medulla?
Their shape and the hormones they produce
What hormones does the zona glomerulosa produce?
Mineralocorticoids -> aldosterone