1.2 The Pineal Gland and Melatonin

Question 1

Where in the brain is the pineal gland located (be as specific as possible)

Answer 1

• Located in the diencephalon - specifically, the epithalamus

Question 2

Describe blood supply/drainage to the pineal gland

Answer 2

Supply: posterior cerebral artery
Drainage: great cerebral vein (comes off straight sinus)

Question 3

The pineal gland can be described as a _________ organ, which means ____, and as a ______ organ, which means.

Answer 3

• Circumventricular: no blood brain barrier
• Neuroendocrine organ: neurons secrete hormones into the bloodstream

Question 4

Innervation of the pineal gland. Which type of fibre (i.e, which division of the nervous system?)

Answer 4

• Sympathetic fibres from superior cervical ganglion

Question 5

The pineal gland receieves neural input from which hypothalamic nucleus?

Answer 5

Suprachiasmatic nucleus

Question 6

Melatonin levels rise in response to what? What are the effects of this on sleepiness?

Answer 6

• Rise in response to darkness
• Increases sleepiness (also increases adenosine to aid in this)