W8 Adrenal glands

Adrenal glands location

Paired bean shaped glands in dorsal abdomen, craniomedial to kidneys

Adrenal gland section

Medullar (inner), Cortex (outer) and connective tissue capsule

Adrenal medulla hormones

Centre of adrenal glands secrete adrenaline (epinephrine) and noradrenaline (norepinephrine)

Adrenaline and Noradrenaline

Catecholamines - hormones controlled by sympathetic nervous system

Adrenaline and noradrenaline action

Fight/flight response by raising bg levels, increase HR, BP

Release adrenaline stimulated by hypoglycaemia, stress, decreased bp and hypothermia

Rich vasuclar supply within adrenal glands allows catecholamines to rapid release into circulation

Adrenaline effect

Fight/flight response:

• Increase cardiac output

• Glycogen breakdown to release glucose (glycogenolysis)

• Fatty acid release

• Increased skeletal muscle tone

• Relaxation of GI smooth muscle

• Urinary retention

• Pupil dilation

• Sweat production

Adrenal cortex

• Zona glomerulosa (outer)

• Zona fasciculata (middle)

• Zona reticularis (inner)

Steroids

All hormones produced by cortex

Adrenocorticotropic hormone (ACTH)

From anterior pituitary gland acts on adrenal cortex, stimulate production of mineralocorticoids and glucocorticoids

Hypothalamus

Release corticotropin-releasing factor (CRF)

Anterior pituitary gland

Release adrenocorticotropic hormone (ACTH)

Adrenal cortex

Produces mineralcorticoids and glucocorticoids

Glucocorticoids

Produced by zona fasciculata and zona reticularis

Adrenal pathology