What is the sphenoid bone and where is it located?

The sphenoid bone is an unpaired, butterfly-shaped bone at the base of the skull. It connects the neurocranium to the facial skeleton and forms part of the floor of the middle cranial fossa.

What are the main parts of the sphenoid bone?

The sphenoid bone consists of four main parts: the body (central cuboidal part), two lesser wings, two greater wings, and two pterygoid processes.

What structures are found on the superior surface of the sphenoid body?

The superior surface of the sphenoid body includes the sella turcica, which houses the pituitary gland in the hypophyseal fossa. Other features are the ethmoidal spine, jugum sphenoidale, sulcus chiasmaticus, tuberculum sellae, and dorsum sellae with clinoid processes.

What is the clinical significance of the sella turcica?

The sella turcica is important in medical imaging, such as skull radiographs, to assess conditions like pituitary tumors or changes in intracranial pressure. It can show enlargement or erosion from tumors.

What are the pterygoid processes and their key features?

The pterygoid processes extend downward from the sphenoid and consist of medial and lateral plates. Notable features include the scaphoid fossa, pterygoid hamulus, pterygoid canal (transmitting nerves and arteries), and vaginal process.

How do the greater wings of the sphenoid bone contribute to the skull?

The greater wings project laterally and contribute to multiple regions: forming part of the floor of the middle cranial fossa, dividing into temporal and infratemporal surfaces, and contributing to the lateral wall of the orbit.

What is the function of the optic canal in the sphenoid bone?

The optic canal is formed between the two roots of the lesser wings and transmits the optic nerve from the orbit to the cranial cavity, playing a key role in vision.

Sphenoid Bone – Body, Wings & Pterygoid Processes

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