Term
embryology of pineal gland
where does it develop from? what's the name of that part?
what does it communicate with? |
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Definition
develops from roof of diencephalon (a dorsal diverticulum - the epiphysis)
communicates with 3rd ventricle in adult
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Term
pinealocytes
where located?
how organized?
what secrete? in response to what hormone?
what enzyme makes it?
during what time?
other function of melatonin?
what other cell type in in pineal gland?
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Definition
in pineal gland
organized into chords/clusters
secrete melatonin (fr tryptophan via seratonin)
convert by Hydroxyinadole-O-methyltransferase
melatonin high at night
melatonin might also stimulate GH by inhib somatostatin
also neuroglial cells (like interstitial cells)
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Term
corpora arenacea
another name?
what made of?
when appear in lifetime?
clinical use? |
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Definition
brain sand in pineal gland
calcified extracellular concentrations of CaPO4 ppt.
appear in early childhood & incr w age
useful radiological markers |
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Term
| affect of tumor in pineal gland? |
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Definition
| tumor may cause delayed sexual development |
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Term
| melatonin synthesis - describe CNS pathway starting when light enters the eye |
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Definition
1. light in eye -> (Retinohypothalamic tract) to Suprachiasmatic Nucleus in hypothalamus.
2. (hypothalamospinal tract) spinal chord -> superior cervical ganglion (preganglionic sympathetic fiber
3. postganglionic sympathetic fiber -> pineal gland
4. suppress melatonin synth
in dark - melatonin is synthesized |
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Term
Melatonin Clinical
1. SAD
2. jet lag |
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Definition
1. Seasonal affected disorder - depression treated with bright light
2. melatonin can counteract drowsiness caused by jet lag |
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