While most people refer to the posterior part of the head simply as “the back of the head,” anatomists and neurologists use a more specific vocabulary to describe this region and the sensitive structures it protects. The human body is a structure of immense complexity, and the skull is no exception. Understanding this precise terminology provides insight into the foundational role this area plays in both physical support and sensory function.
The Occipital Bone
The single, unpaired bone forming the lower and posterior portion of the cranium is called the occipital bone. This term, derived from the Latin word occiput meaning “back of the head,” is the anatomically correct name for the bony shell at the rear of the skull. The occipital bone is classified as a flat bone, providing broad protection for underlying brain structures and serving as an anchor point for muscles and ligaments.
This bone is situated at the back of the head, articulating with several neighboring bones to complete the protective casing of the brain. Superiorly, it meets the two parietal bones along a jagged line known as the lambdoid suture. Inferiorly and laterally, it connects with the mastoid portion of the temporal bones. The structure acts as a foundational plate, forming both the posterior wall and a significant part of the base of the skull.
The Occipital Lobe and Vision
Directly sheltered beneath the occipital bone is the smallest of the four major brain lobes, the occipital lobe. This area is entirely dedicated to processing visual information and is often referred to as the visual cortex. Signals originating from the eyes travel along the optic nerve to this posterior region, where they are decoded into the images we perceive.
The occipital lobe is responsible for complex visual processing, including the recognition of color, form, motion, distance, and depth perception. Because of its location, trauma to the back of the head can cause sudden visual disturbances, even if the eyes remain undamaged. This impact can disrupt the lobe’s ability to interpret signals, potentially leading to visual field deficits or cortical blindness.
Important Structural Landmarks
The occipital bone contains several distinctive physical features important for structural and neurological reasons. The most prominent feature is the Foramen Magnum, a large, oval-shaped opening located at the base of the bone. This aperture is the largest opening in the skull and acts as the passageway connecting the brain to the spinal cord.
Foramen Magnum
The brainstem, specifically the medulla oblongata, passes through the Foramen Magnum, along with the vertebral arteries and various nerves. The placement of this opening is significant for maintaining upright posture and connecting the skull to the first cervical vertebra, known as the atlas. This connection is formed by the occipital condyles, which are rounded knobs on either side of the Foramen Magnum that articulate with the atlas.
External Occipital Protuberance
Another identifiable feature is the External Occipital Protuberance, the small, palpable bump felt at the rear of the head, just above the neck. This bony prominence serves as an anchor point for the nuchal ligament, a strong band of tissue that supports the head. The muscles and ligaments attaching here make this area susceptible to strain from sudden, forceful movements, such as whiplash injuries.