Sphenoid Bone

SPHENOID

It is an irregular, odd bone and is located at the base of the skull anterior to the temporal and basilar portion of the occipital bone.

The sphenoid bone is divided into:

  • Body (1)
  •  Smaller Wings (2)
  •  Larger Wings (2)
  • Pterygoid Processes (2).

Body

a) Upper Face:

 Pituitary Fossa

 Middle and Later Clinoid Processes

 Ethmoidal Spine & #8211; articulates with the crustal lamina of the ethmoid bone

 Turtle Saddle & #8211; houses the pituitary

 Clivo & #8211; upper bridge support

b) Previous Face:

 Sphenoidal Crest & #8211; forms part of the septum of the nose

 Sphenoidal Sinus & #8211; cavities filled with air (pneumatic bone) and serve to lighten the skull. They are rarely symmetrical.

c) Bottom Face:

 Sphenoidal Rostrum & #8211; triangular spine at midline

 Vaginal Process & #8211; on each side of the sphenoid rostrum

d) Side Face:

 Carotid Groove & #8211; groove shaped & #8220; S & #8221;

 Tongue & #8211; bony crest in the angle between the body and the larger wing

Smaller Wings

 Optical Channel & #8211; optic nerve passage (2nd cranial pair) and ophthalmic artery

 Previous Clinoid Process

Larger Wings

 Round Forame & #8211; maxillary nerve passage (5th cranial pair & #8211; trigeminal nerve)

 Oval foramen & #8211; mandibular nerve passage (5th cranial pair & #8211; trigeminal nerve) and accessory meningeal artery

 Prickly foramen & #8211; passage of middle meningeal vessels and a branch of the mandibular nerve

 Sphenoidal Spine

 Temporal face

 Orbital Face

Processes Pterigoids

 Medial Pterygoid Blade

 Lateral Pterygoid Blade

 Pterigoid Fossa

 Pterigoid notch & #8211; between the two blades

Between the Smallest and Largest Wings:

 Superior Orbital Cleft or Sphenoid Cleft & #8211; oculomotor nerve passage (3rd cranial pair), trochlear nerve (4th cranial pair), trigeminal nerve ophthalmic segment (5th cranial pair) and abducens nerve (6th cranial pair)

SPHENOID & #8211; PREVIOUS VIEW
 Sphenoid Bone - Anterior View
Source: SOBOTTA, Johannes. Atlas of Human Anatomy. 21st. Rio de Janeiro: Guanabara Koogan, 2000.
SPHENOID & #8211; BACK VIEW
 Sphenoid Bone - Posterior View
Source: SOBOTTA, Johannes. Atlas of Human Anatomy. 21st. Rio de Janeiro: Guanabara Koogan, 2000.

 

Neurocranium
Eight (08) bones
Frontal (01)
Occipital (01)
Ethmoid (01)
Thunderstorm (02)
Parietal (02)