The Middle Cranial Fossa is a depression in the skull located between the posterior cranial fossa and the anterior cranial fossa. It is located at the base of the skull, behind the orbits (eye sockets) and in front of the foramen magnum (the opening at the base of the skull through which the spinal cord passes).
Appearance
The Middle Cranial Fossa is bordered by several bones of the skull, including the sphenoid bone, the temporal bones, and the frontal bone. The sphenoid bone is a butterfly-shaped bone that sits at the center of the skull, forming the base of the Middle Cranial Fossa. The temporal bones are a pair of bones located on either side of the skull, forming the sides of the Middle Cranial Fossa. The frontal bone is a single bone located at the front of the skull, forming the roof of the Middle Cranial Fossa.
Within the Middle Cranial Fossa are several important structures, including the following:
- The sella turcica: This is a depression in the sphenoid bone that houses the pituitary gland. The pituitary gland is a small endocrine gland located at the base of the brain that produces hormones that regulate various body functions, including growth, metabolism, and reproduction.
- The optic nerves: These are the nerves that carry visual information from the eyes to the brain. They pass through the Middle Cranial Fossa on their way to the brain.
- The olfactory nerves: These are the nerves that carry the sense of smell from the nose to the brain. They pass through the Middle Cranial Fossa on their way to the brain.
- The trigeminal nerve: This is a large cranial nerve that carries sensory information from the face to the brain. It passes through the Middle Cranial Fossa on its way to the brain.
Location
As mentioned above, the Middle Cranial Fossa is located at the base of the skull, between the posterior cranial fossa and the anterior cranial fossa. It is located behind the orbits (eye sockets) and in front of the foramen magnum (the opening at the base of the skull through which the spinal cord passes).
Function
The Middle Cranial Fossa is important for several functions, including the following:
- Housing the pituitary gland: As mentioned above, the pituitary gland is located in the sella turcica within the Middle Cranial Fossa. The pituitary gland produces hormones that regulate various body functions, including growth, metabolism, and reproduction.
- Carrying sensory information to the brain: The optic nerves, olfactory nerves, and trigeminal nerve all pass through the Middle Cranial Fossa on their way to the brain. These nerves carry visual, olfactory, and sensory information from the eyes, nose, and face to the brain, respectively.
- Protecting the brain: The Middle Cranial Fossa, along with the other cranial fossae, provides structural support for the brain and protects it from injury.
Clinical Significance
There are several conditions that can affect the structures within the Middle Cranial Fossa, including the following:
- Pituitary gland disorders: The pituitary gland, which is located in the sella turcica within the Middle Cranial Fossa, can be affected by various disorders. These can include hormonal imbalances, tumors, and inflammation.
- Optic nerve disorders: The optic nerves, which pass through the Middle Cranial Fossa on their way to the brain, can be affected by various disorders. These can include optic neuritis, which is an inflammation of the optic nerve that can cause vision loss, and glaucoma, which is a condition that can damage the optic nerve and lead to vision loss.
- Olfactory nerve disorders: The olfactory nerves, which carry the sense of smell from the nose to the brain and pass through the Middle Cranial Fossa, can be affected by various disorders. These can include anosmia, which is the loss of the sense of smell, and hyposmia, which is a decrease in the sense of smell.
- Trigeminal nerve disorders: The trigeminal nerve, which carries sensory information from the face to the brain and passes through the Middle Cranial Fossa, can be affected by various disorders. These can include trigeminal neuralgia, which is a condition that causes facial pain, and Bell’s palsy, which is a condition that causes weakness or paralysis of the facial muscles.
- Skull fractures: The bones of the Middle Cranial Fossa, including the sphenoid bone, temporal bones, and frontal bone, can be fractured due to injury or trauma. These fractures can cause serious complications, such as brain injury or damage to the nerves and blood vessels in the area.
