Endogenous Pacemakers

Question 1

The main endogenous pacemaker is the

Answer 1

Suprachaismatic Nucleus
Small bundle of neurons in the hypothalamus
Located above the optic chains (where nerves from each eye cross over)

Question 2

It comprises of two structures, one in each hemisphere of the brain

Answer 2

Ventral- affected by external cues

Dorsal- more resistant to external cues

Question 3

The SCN has an internal activity rhythm which persists even when isolated from the rest of the brain

Answer 3

In the absence of external cues the SCN will free run to a rhythm of approximately 25 hours or so opposed to 24

Question 4

Second endogenous pacemaker is the

Answer 4

Pineal glad

Question 5

This is a small pea shaped gland responsible for converting the neurotransmitter

Answer 5

Serotonin into melatonin
When melatonin is released into circulation, it acts on brains sleep mechanisms causing a reduction in alertness and drowsiness