Metastasis to the brain can occur by way of Batson's plexus or by direct extension from adjacent structures such as the sphenoid bone or sinuses. Sinuses are air-filled sacs empty spaces on either side of the nasal cavity that filter and clean the air breathed through the nose and lighten the bones of the skull. The notched lateral margin forms a joint with the zygomatic bone. In addition to articulations with all of these bones, the sphenoid bone may also be affected by or affect the mandible. The periorbita is loosely attached to the bones except at sutures, foramina and the orbital margin where it is firmly attached.
The pituitary gland hypophysis lies in the seat of the sella turcica. The purple bone is the occipital bone. If you do not agree to the foregoing terms and conditions, you should not enter this site. The sphenoid bone is one of the of the head. The bone is a single unit instead of being paired.
It consists of a body, paired greater wings and lesser wings, and two pterygoid processes. By placing my thumbs on your temples and cupping the rest of my hands around the back of the head, I will gently assess the movement of the sphenoid, and use about 5 grams the weight of a nickel of pressure to invite the sphenoid to reorient itself. The roof of the orbit is made up mainly by the frontal bone and behind this by the lesser wing of the sphenoid. The bones are much thicker at the margin rim than they are along the walls of the orbital cavity. Majority of the sphenoid bone becomes ossified when it is still in a cartilaginous state. It consists of a body, paired greater wings and lesser wings, and two pterygoid processes. Clinical Significance — Transsphenoidal Surgery The sphenoid bone shares a close anatomical relationship with the pituitary gland.
The petrosal process also serves as the median border of the foramen lacerum. The sphenoid will affect all of these bones, and all of these bones will affect the sphenoid. Like the nasal cavity, the sinuses are all lined with mucus. These processes run through the middle of every medial pterygoid plate. Sphenoid Bone Functions The sphenoid bone mainly plays a key role in development of important anatomical structures and also, in the formation of the skull.
The distinctive butterfly-shape of the sphenoid as seen from above. The extremely concave surface of each greater wing makes up part of the middle fossa of the skull, which houses the temporal lobes of the brain. Its superior saw-like border joins at the front with the orbital plate. However, the pituitary takes its instruction from the hypothalamus, which regularly monitors the hormone levels in the bloodstream. The lesser wings of the sphenoid bone also spread outward, forming the posterior portion of the orbital roof on each side. For now, it is amazing to think that this one bone can affect and be affected by so many other structures.
The pituitary gland, which produces many different hormones that control other glands, is housed in the sphenoid bone. It contains the sphenoidal sinuses, which are separated by a septum — meaning that the sphenoid body is essentially hollow. In addition to the bones that can affect or will be affected by the sphenoid, within the sella turcica of the sphenoid bone sits the pituitary. Some people have this articulation and some do not. By 2019 Fig 1 — The position of the sphenoid bone yellow within the facial skeleton. In addition, the fissure contains the ophthalmic division of the , which supplies sensation to the upper face, and the superior and inferior ophthalmic veins, which drain blood from the eye and orbit. It is pierced by the and , and at its posterior part is the , which is frequently grooved on its medial surface for the.
Body The body lies at the centre of the sphenoid bone, and is almost completely cubical in shape. The pituitary and hypothalamus communicate through the hypophyseal stalk also called the infundibulum stalk , a bridge traveling between the two. Table O3 Bones forming the walls of the orbit roof medial wall 1. It is quadrangular in shape forming the posteroinferior part of the nasal septum. The orbital cavity has the approximate form of a pyramid. The superior section of a pons, i. By visiting this site you agree to the foregoing terms and conditions.
The upper half is the temporal section and a component of the temporal fossa as well as attaches with the Temporalis. It is the deepest section and clinically known as the hypophyseal fossa. The primary component of the sella turcica is the sphenoid bone with a component from the basiocciput. It constitutes the cranium or skull. In the front and middle part, is the foramen rotundum, a circular opening through which passes the maxillary nerve.
Pathologies Related to Sphenoid Injuries, wounds, and fractures involving the bat bone are usually rare because of its embedded location. For example, the scapula is influenced in its alignment and articulations by the humerus. These structures include the oculomotor, trochlear, and abducens nerves, which provide the nerve supply to the muscles that move each eye. . This is due to the sphenomandibular ligament, which attaches to both bones, and to the lateral and medial pterygoid muscles. Often, they go up to the base of the occipital bone, coinciding with the foramen magnum in the skull through which the spinal cord passes.
Both the lateral and medial pterygoid muscles have originations on the lateral pterygoid plate of the sphenoid bone, and insertions on the mandible. Because of its location it can affect the pituitary gland, the nervous system and blood flow to and from the brain. Which means that the scapula can be influenced by the ulnar and the radial position because of how they affect the humerus. Nerve irritation, nasal drainage, pain in the facial muscles and eye sockets behind which lie the body of sphenoid , and headaches are usual symptoms. Bone s Joint s Occiput bone Sphenobasilar joint Frontal bone Sphenofrontal suture Temporal bones Sphenosquamosal sutures Parietal bones Sphenoparietal sutures Ethmoid bone Sphenoethmoid suture Vomer bone Sphenovomerine suture Zygomatic bones Sphenomalar sutures Palatine bones Sphenopalatine sutures Maxillary bones Sphenomaxillary sutures It is important to note that the sphenomaxillary sutures do not exist in all people. The medial wall of the orbit consists of: 1 the frontal process of the maxilla maxillary ; 2 the lacrimal bone; 3 the lamina papyracea of the ethmoid; and 4 a small part of the body of the sphenoid.