Pineal gland

Glandula pinealis

A small, pine cone-shaped gland located posterior to the third ventricle at the epithalamus, between the two superior colliculi. It receives sympathetic innervation via the superior cervical ganglion. Pinealocytes produce melatonin from serotonin in response to darkness signals from the retina.

Type Gland
Body System Endocrine
Body Region Brain
Latin Name Glandula pinealis
FMA ID 62033

Function

Produces melatonin, which regulates circadian rhythms (sleep-wake cycles) and seasonal biological rhythms. Melatonin production increases in darkness and decreases with light exposure.

Clinical Significance

Pineal tumors can cause obstructive hydrocephalus due to compression of the cerebral aqueduct. Pineal calcification is a normal finding on CT scans and can serve as a midline marker. Disrupted melatonin production affects sleep disorders and jet lag.

Frequently Asked Questions

What is the pineal gland?
The pineal gland is a small, pine cone-shaped gland located posterior to the third ventricle at the epithalamus, nestled between the two superior colliculi. It is part of the endocrine system and plays a role in regulating circadian rhythms.
Where is the pineal gland located?
The pineal gland is situated at the epithalamus, posterior to the third ventricle, between the two superior colliculi of the midbrain. It occupies the center of the brain at roughly the midline.
What is the function of the pineal gland?
The pineal gland's primary function is to produce melatonin from serotonin in response to darkness signals relayed from the retina. This melatonin secretion helps regulate the sleep-wake cycle and circadian rhythms.
What conditions may be associated with the pineal gland?
Pineal gland abnormalities may be associated with disrupted melatonin production, which is involved in sleep disorders and circadian rhythm disturbances. Pineal cysts and rare pineal tumors are also known to affect this structure.
What does the pineal gland look like?
The pineal gland is a small, pine cone-shaped structure, typically about 5–8 mm in length. It receives sympathetic innervation via the superior cervical ganglion and appears as a reddish-gray nodule on brain imaging.

Related Structures

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Educational Disclaimer

This content is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider for medical decisions.

Data sources: Terminologia Anatomica, Foundational Model of Anatomy, Wikidata.