Adrenal Glands Flashcards
Outline the 2 devisions of the adrenal glands
Outer layer is cortex. Yellow
Inner layer is medulla. Red or Grey
Where are Adrenal glands located
Superior to each kidney
Outline the structure of the adrenal glands
Made of 2 seperate glands
Adrenal cortex - outer region, has 3 layers, secretes steroid hormones, secretes cortisol
Adrenal medulla - central region, part of sympathetic nervous system, secretes mainly adrenaline
Outline the 3 layers of the adrenal cortex
Outer layer secretes aldosterone
Middle layer secretes cortisol
Inner layer secretes androgens
Outline Adrenaline
Adrenaline and noradrenaline (epinephrine and norepinephrine) are secreted as part of sympathetic nervous systems response to stress
Adrenaline + noradrenaline secretion from adrenal medulla supplements actions of sympathetic nervous system, particularly in times of stress.
Outline the adrenal medulla pathway to effector cells
Sympathetic preganglionic fibre synapses at adrenal medulla
Releases adrenaline (80%) and noradrenaline (20%) neurohormones into blood stream. Hormones travel to, bind to, and mediate response from target/effector cells
Outline the sympathetic chain ganglion pathway to effector
Sympathetic preganglionic fibre synapses at sympathetic chain ganglion
Post ganglionic fibres synapse at effector cell, releasing norepinephrine
Outline the process of adrenaline adrenaline stimulating cell
water soluble hormone (amino acids derivative)
Cell embrane receptor
Uses secondary messenger system
Amplification of cellular response
Fast
Outline the process of adrenaline secretion
Stimulus: stress
Hypothalamus stimulates sympathetic preganglionic fibres
Adrenal medulla stimulated to secrete adrenaline
Effects: Increased breakdown of glycogen to to glucose in skeletal muscle and liver
Increased breakdown of fat to fatty acid in adipose tissue
Stimulus reduced when stress is recused
What is the overall effect of adrenaline secretion
Makes fuel (glucose and fatty acids) more readily available to cells
