12. Adrenals, Ureter and Bladder Flashcards
(118 cards)
paired endocrine glands situated over the medial aspect of the upper poles of each kidney.
adrenal glands
shape of right adrenal gland
pyramidal in shape
shape of left adrenal gland
semi-lunar
encloses the adrenal glands and the kidneys. This fascia attaches the glands to the crura of the diaphragm.
They are separated from the kidneys by the perirenal fat.
renal fascia /perinephric fascia
The adrenal glands consist of
capsule
cortex
medulla
Veins and lymphatics leave each adrenal gland via
hilum
arteries and nerves enter the glands at numerous sites.
adrenal cortex is derived from
embyronic mesoderm
adrenal medulla is derived from
ectodermal neural crest cells
this portion of adrenal gland is yellowish in color
cortex
cortex can be divided into 3 zones
superficial -> deep
- zona glomerulosa
- zona fasciculata
- zona reticularis
produces and secretes mineralocorticoids such as aldosterone.
Zona glomerulosa
produces and secretes corticosteroids such as cortisol. It also secretes a small amount of androgens.
Zona fasciculata
produces and secretes androgens such as dehydroepiandrosterone (DHES). It also secretes a small amount of corticosteroids.
Zona reticularis
dark brown in colour
portion of the adrenal gland
medulla
medulla contains this cells
chromaffin cells
secrete catecholamines (such as adrenaline) into the bloodstream in response to stress
also secrete enkephalins which function in pain control.
chromaffin cells
adrenal glands have a rich blood supply via three main arteries
Superior adrenal artery – arises from the inferior phrenic artery
Middle adrenal artery – arises from the abdominal aorta.
Inferior adrenal artery – arises from the renal arteries.
venous drainage of the adrenal glands
Right and left adrenal veins drain the glands.
The right adrenal vein drains into the inferior vena cava, whereas the left adrenal vein drains into the left renal vein.
innervation of the adrenal gland
coeliac plexus
greater splanchnic nerves.
Sympathetic innervation to the adrenal medulla - mainly from the T10 to L1 spinal cord segments.
lymphatic drainage of adrenal glands
lumbar lymph nodes by adrenal lymphatic vessels.
These vessels originate from two lymphatic plexuses – one deep to the capsule, and the other in the medulla.
a tumour of the adrenal medulla or preganglionic sympathetic neurones. It secretes adrenaline and noradrenaline uncontrollably, causing blood pressure to greatly increase.
Patients may present with palpitations, headaches and diaphoresis (profuse sweating).
pheochromocytoma
competitive, irreversible antagonist of adrenaline, can be used in treatment to reduce blood pressure by binding to adrenaline receptors, making less available for adrenaline to act upon.
phenoxybenzamine
adrenal gland
normal weight
4 grams
75% of the cortex is the
zone fasciculata