Pineal Gland

Question 1

What does the pineal gland develop from?

Answer 1

neuroectoderm of the posterior portion of the roof of the diencephalon & remains attached via a small stalk

Question 2

Where is the pineal gland located

Answer 2

posterior wall of the third ventricle near the center of the brain; covered by pia matter

Question 3

What is the function of the pineal gland?

Answer 3

releases melatonin in response to the dark, Through the retinohypothalamic tract, regulates daily body rhythms & day/night cycles and steroidgenic activity of the gonads (particularlu menstrual cycle)

Question 4

What divides the pineal gland into lobules?

Answer 4

connective tissue trabeculae, extend from the capsule into the substance of the gland, contains the blood vessels

Question 5

What are pinealocytes?

Answer 5

chief cells of the pineal gland that produce melatonin, arranged in clumps/cords within lobules
large, deeply infolded nuclei with prominent nucleoli, euchromatic nuclei

Question 6

What are interstitial glial cells?

Answer 6

closely resemble astrocytes or look similar to pituicytes, elongated nuclei that stain more heavily than pinealocytes, usually found in perivascular areas & between groups of pinealocytes

Question 7

What is brain sand?

Answer 7

corpora arenacea, predominantly composed of calcium and magnesium salts, not pathological, appear white on an MRI and scans, natural landmark used by radiologists and neurologists

Question 8

What runs along the septa in the pineal gland?

Answer 8

unmyelinated tracts of sympathetic fibers, associated indirectly with photoreceptive neurons in the retinas and running to the pinealocytes to stimulate melatonin release in periods of darkness