[Endocrinology] The pineal gland

Back to endocrinology

This structure is a component of the brain.
The pineal gland regulates sleep and metabolism.

 

Input

Inhibited by

• Sensation of light by retinal cells, via the suprachiasmatic nucleus (SCN)

 

Output

• Melatonin: modulates CNS activity to promote sleep
• Unknown signalling mechanism: modulates pituitary gland activity, increases the concentration of FSH and LH within the pituitary gland

 

Function

The suprachiasmatic nucleus (SCN) is a structure in the brain, which regulates the circadian rhythm of the body. The SCN receives information from the retinae about the levels of available light and becomes oriented to the time of day. It modulates the activity of the pineal gland to promote sleep and modulate metabolism.

Hormones

• Melatonin

 

Pathology

• Circadian rhythm disturbances 
• Evening use of artificial light sources is a risk factor for sleep disturbances, including insomnia. White light sources which produce a high proportion of blue light (high frequency visible light waves) are particularly potent at inhibiting melatonin secretion.
• Metabolic disturbances  
• Excessive or insufficient levels of sleep are a risk factor for developing type 2 diabetes.