Adrenal glands Flashcards
How many arteries vascularize the adrenal glands?
3 arteries:
Superior superenal artery
Middle superrenal artery
Inferior Superrenal artery
What is the superior superenal artery a branch of?
from the inferior phrenic artery
What is the Middle superrenal artery a branch of?
from the aorta
What is the inferior superenal artery a branch of?
from the renal artery
How does the body supply blood to the artery exactly?
By forming a subcapsular plexus, from which arise 3 groups of vessels
What are three groups of vessels that directly are involved in the blood supply of the adrenal glands? how?
- arteries of the capsule
- arteries of the cortex that drain into the medulla
- Arteries of the medulla that pass through the cortex and form medullary capillaries
Is the medulla vascularized by a single blood supply or dual? Explain the system.
Dual blood supply.
- it has an arterial supply and a venous supply
What are the medullary veins of the adrenal glands made of?
medullary capillaries and cortical capillaries –
How is the adrenal/superenal vein formed?
when the medullary veins join together, they form the adrenal/superenal vein
Where is the adrenal gland(s) located?
lie near the superior poles of each kidney
T/F: Cortex and medulla are 2 organs with distinct origins and functions, but similar morphological characteristics.
False. Even their morphological characteristics differ.
What are the embryonic origins of the cortex? medulla?
Cortex - coelomic intermediate mesoderm
medulla - neural crest cells
Is the Adrenal cortex divided into zones? How many? What are they?
Yes. Three.
Zona glomerulosa
Zona fasiculata
Zona reticularis
What precentage of the cortex does each zone occupy?
Glomerulosa: 15%
Fasiculata: 65%
Reticularis: 7%
How are the cells of the zona glomerulosa arranged?
closely packed rounded clusters
What does the zona glomerulosa secrete?
mineralcorticoids, such as aldosterone
How are the cells of the zona fasiculata arranged?
arranged as straight cords that run perpendicular to the surface: 1-2 cells thick
What does the zona fasiculata secrete?
Glucocorticoids: such as cortisone and cortisol
Why do the cells of the zona fasiculata appear so pale?
They store lipid droplets and therefore, appear vacuolated
How are the cells of the Zona Reticularis arranged?
arranged as irregular cords
What do the cells of the Zona reticularis secrete?
Secrete androgens and small amounts of estrogens
Do Cortical cells store hormones as granules? Why?
No because hormones are synthesized and secreted upon demand
How are the cells of the adrenal medulla arranged?
arranged in a cords or clumps of polyhedral cells
Whats so special about the adrenal medulla cells?
considered modified sympathetic post-ganglionic neurons –> they have lost their axons and dendrites to become secretory cells
Is the adrenal medulla vascularized? innervated?
Profuse capillary supply with a few parasympathetic ganglion cells
What is another name for the cells of the medulla?
chromaffin cells
Does the adrenal cortex cells contain secretory granules? Medulla?
Cortex - No, because it releases steroid hormones. Medulla - yes. It secretes catecholamines - epinepherine and norepinepherine
What do the granules in chromaffin cells contain?
Catecholamines, ATP, chromogranin (binding protein), and an opiate-like peptide
How are the cells of the adrenal medulla innervated?
by cholinergic endings of preganglionic sympathetic neurons
