Adrenal gland Flashcards
what are the adrenal glands?
The adrenal (or suprarenal) glands are paired retroperitoneal (lying posterior to the peritoneum) endocrine glands
where are the adrenal glands situated?
over the medial aspects of the upper poles of each kidney
what do the adrenal glands secrete and where does it secrete into?
They secrete steroid and catecholamine hormones directly into the blood
where do the adrenal glands lie within the abdomen?
the posterior abdomen
what is the adrenal glands situated between?
between the superomedial kidney and the diaphragm
what does the superomedial kidney and the diaphragm cover of the kidney?
They cover part of the anterior surface of each kidney
what shape are the left and right glands of the adrenal glands?
The right gland is pyramidal in shape, contrasting with the semi-lunar shape of the left gland
what encloses the adrenal glands and the kidneys?
Perinephric (or renal) fascia encloses the adrenal glands and the kidneys
what does the perinephric fascia attach the glands to?
crura of the diaphragm
what is the crura of the diaphragm separated from the kidneys by?
the perirenal fat
what is anterior to the right adrenal gland?
inferior vena cava
right lobe of liver
what is posterior to the right adrenal gland?
right crus of the diaphragm
what is anterior to the left adrenal gland?
stomach, pancreas, spleen
what is posterior to the left adrenal gland?
left crus of the diaphragm
what does the adrenal glands consist of?
an outer connective tissue capsule, a cortex and a medulla
what do veins and lymphatics leave each gland via?
the hilum
where do arteries and nerves enter the adrenal glands?
at numerous sites
what are the functional portions of the adrenal glands?
The outer cortex and inner medulla
what are the outer cortex and inner medulla like in terms of glands?
2 separate endocrine glands with different embryological origins
what is the outer cortex derived from embryologically?
embryonic mesoderm
what is the medulla derived from embryologically?
ectodermal neural crest cells
what is outer cortex and inner medulla each responsible for?
different secretions
what colour is the cortex?
The cortex is yellowish in colour
what does the cortex secrete?
2 cholesterol derived hormones - corticosteroids and androgens
functionally, how can the adrenal cortex be divided into? (how many regions and what are they from superficial to deep?)
three regions which are (from superficial to deep):
zona glumerulosa
zona fasiculata
zona reticularis
What does the zona glumerulosa produce and secrete? what is an example?
mineralocorticoids e.g. aldosterone
What does the zona fasciculata produce and secrete? e.g.?
corticosteroids e.g. cortisol
also secretes small amounts of androgen
what does the zona reticularis produce and secrete? e.g.?
androgens e.g. dehydroepiandrosterone (DHES)
also secretes small amounts of corticosteroids
where does the medulla lie within the adrenal glands? (what colour is it?)
within the centre
dark brown in colour
what does the medulla secrete (e.g.) and where does it secrete into?
catecholamines e.g. adrenaline directly into the bloodstream (post-ganglionic goes directly into the blood rather than an organ)
when is adrenaline secreted from the medulla of the adrenal glands? what does it produce?
under stress
produces flight or fight response
which part of the medulla of adrenal glands secrete adrenaline?
chromaffin cells
what else do chromaffin cells secrete and when?
enkephalins function in pain control
how is the blood supply to the adrenal glands like and how many arteries does it receive its blood supply via?
rich blood supply
via 3 different arteries
what are the 3 arteries which supply the adrenal glands?
superior, middle and inferior adrenal arteries
where does the superior adrenal artery arise from?
inferior phrenic artery
where does the middle adrenal artery arise from?
abdominal aorta
where does the inferior adrenal artery arise from?
renal arteries
what drains the adrenal glands?
right and left adrenal veins
where does the right adrenal vein drain into?
inferior vena cava
where does the left adrenal vein drain into?
left renal vein
describe the lymph drainage of the adrenal glands
lymph drainage goes to the lumbar lymph nodes by adrenal lymphatic vessels
where do the adrenal lymphatic vessels originate from?
2 lymphatic plexus:
1 deep into the capsule
the other located within the medulla
what are the adrenal glands innervated by?
celiac plexus
abdominopelvic splanchnic nerves
what is sympathetic innervation to the adrenal medulla via?
myelinated pre-synaptic fibres
mainly T10-L1 spinal cord segments
