The Pineal Gland - Podcast Version 0:00 / 0:00 1x 0.25x 0.5x 0.75x 1x 1.25x 1.5x 1.75x 2x The pineal gland is a small endocrine gland located within the brain. Its main secretion is melatonin, which regulates the circadian rhythm of the body. It is also thought to produce hormones that inhibit the action of other endocrine glands in the body. In this article, we shall look at the anatomy of the pineal gland – its structure, position and vasculature. Pro Feature - 3D Model You've Discovered a Pro Feature Access our 3D Model Library Explore, cut, dissect, annotate and manipulate our 3D models to visualise anatomy in a dynamic, interactive way. Learn More Anatomical Structure and Position The pineal gland is small glandular body, approximately 6mm long. It is shaped like a pine cone, from which its name is derived. There are two types of cells present within the gland: Pinealocytes – hormone secreting cells. Glial cells – supporting cells. In middle age, the gland commonly becomes calcified, and can be subsequently identified on radiographs and CT scans of the head. Anatomical Position The pineal gland is a midline structure, located between the two cerebral hemispheres. It is attached by a stalk to the posterior wall of third ventricle. In close proximity to the gland are the superior colliculi of the midbrain – paired structures that play an important role in vision. By TeachMeSeries Ltd (2026) Fig 1Sagittal section of the brain, showing the midline position of the pineal gland Vasculature The arterial supply to the pineal gland is profuse, second only to the kidney. The posterior choroidal arteries are the main supply; they are a set of 10 branches that arise from the posterior cerebral artery. Venous drainage is via the internal cerebral veins. Clinical Relevance Pineal Gland Tumours Pineal glands tumours are a diverse group of neoplasms. The most common is a germ cell tumour, which arises from residual embryonic tissue in the gland. It presents with the classical symptoms of a space occupying lesion – headache, nausea and vomiting. The tumour can also cause Parinaud syndrome – inability to move the eyes upwards – this is due to compression of the superior colliculi. In addition, obstruction of the cerebral aqueduct may produce hydrocephalus. In children, a pineal gland tumour (which invades and destroys the gland), produces an accelerated onset of puberty. Thus, it is thought that one of the functions of the gland is to inhibit sexual development. Do you think you’re ready? Take the quiz below Pro Feature - Quiz The Pineal Gland Question 1 of 3 Submitting... Skip Next Rate question: You scored 0% Skipped: 0/3 1800 More Questions Available Upgrade to TeachMeAnatomy Pro Challenge yourself with over 1800 multiple-choice questions to reinforce learning Learn More Frequent questions What is the primary function of the pineal gland? The pineal gland primarily secretes melatonin, a hormone that regulates the body's circadian rhythm. It is also believed to produce hormones that inhibit the activity of other endocrine glands. Where is the pineal gland located in the brain? The pineal gland is situated midline between the two cerebral hemispheres and is attached to the posterior wall of the third ventricle. Its proximity to the superior colliculi of the midbrain is significant for visual functions. What types of cells are found in the pineal gland? The pineal gland contains two main types of cells: pinealocytes, which are responsible for hormone secretion, and glial cells, which provide support. This cellular composition is essential for the gland's endocrine functions. How does the vasculature of the pineal gland function? The pineal gland receives a rich blood supply primarily from the posterior choroidal arteries, which are branches of the posterior cerebral artery. Venous drainage occurs through the internal cerebral veins. What are the clinical implications of pineal gland tumours? Pineal gland tumours, particularly germ cell tumours, can lead to symptoms such as headaches, nausea, and vomiting due to their space-occupying nature. They may also cause Parinaud syndrome and obstructive hydrocephalus, impacting eye movement and cerebrospinal fluid flow. Rate This Article