Advanced Adrenal Medulla Quiz

Q1. Why can the adrenal medulla be described as a specialized sympathetic ganglion?

• Chromaffin cells act as modified postganglionic sympathetic neurons that secrete into blood
• It is derived from mesoderm like the adrenal cortex
• It contains only ordinary sensory neurons
• It sends postganglionic axons to every abdominal organ

Q2. What developmental process places neural crest-derived chromaffin cells within the adrenal cortex?

• Neural crest cells migrate into the developing cortical primordium
• Foregut endoderm invaginates into the cortex
• Cortical cells transform directly into neurons
• Renal tubular cells migrate into the adrenal gland

Q3. Why does the adrenal medulla receive both cortical sinusoidal blood and a direct arterial supply?

• One supply carries urine and the other carries lymph
• The cortex has no vascular connection to the medulla
• Direct arteries supply only the adrenal capsule
• It combines oxygenated blood with glucocorticoid-rich cortical blood

Q4. How does cortisol favor epinephrine production in the adrenal medulla?

• Cortisol converts epinephrine directly into norepinephrine
• Cortisol destroys chromaffin granules
• Cortisol increases PNMT expression
• Cortisol blocks all catecholamine enzymes

Q5. What is the biochemical role of PNMT in chromaffin cells?

• Conversion of norepinephrine to epinephrine
• Conversion of cholesterol to pregnenolone
• Conversion of dopamine to norepinephrine
• Conversion of tyrosine to DOPA

Q6. Why are catecholamine-containing chromaffin granules important structurally?

• They store catecholamines for regulated exocytosis
• They transport urine into the central vein
• They form the adrenal capsule
• They synthesize steroid hormones from cholesterol

Q7. What is the significance of the term chromaffin?

• Catecholamines produce a characteristic color reaction with chromium salts
• The cells contain abundant melanin
• The cells stain because of calcium deposits
• Their nuclei contain chromium metal

Q8. Why can a catecholamine-secreting tumor of chromaffin cells produce widespread systemic effects?

• Catecholamines are released directly into the systemic circulation
• Catecholamines remain confined inside the gland
• The tumor secretes only into the renal pelvis
• Chromaffin cells send motor axons to every organ

Q9. How does adrenal medullary innervation support a rapid stress response?

• The medulla lacks direct neural input
• Direct preganglionic stimulation rapidly releases stored catecholamines
• A long endocrine feedback loop must first create new neurons
• Parasympathetic ganglia slowly synthesize catecholamines

Q10. Which statement best integrates adrenal medulla anatomy and function?

• It is an avascular collection of parasympathetic neurons
• It is a renal medullary extension responsible for concentrating urine
• It is a vascular neural crest-derived sympathetic neuroendocrine tissue specialized for rapid catecholamine secretion
• It is a mesoderm-derived steroidogenic zone controlled mainly by ACTH