Search results
Results from the WOW.Com Content Network
The mastoid foramen is a hole in the posterior border of the temporal bone of the skull. [1] The opening of the mastoid foramen is an average of 18 mm from the asterion, [2] and around 34 mm from the external auditory meatus. [3] It is typically very narrow. [1] [3] This may be around 2 mm. [3]
The inner surface of the mastoid portion presents a deep, curved groove, the sigmoid sulcus, which lodges part of the transverse sinus; in it may be seen in the opening of the mastoid foramen. The groove for the transverse sinus is separated from the innermost of the mastoid cells by a very thin lamina of bone, and even this may be partly ...
The mastoid portion is at first flat, with the stylomastoid foramen and rudimentary styloid immediately behind the tympanic ring. With air cell development, the outer part of the mastoid component grows anteroinferiorly to form the mastoid process, with the styloid and stylomastoid foramen now on the under surface.
In the temporal bone, between the posterior wall of the external acoustic meatus and the posterior root of the zygomatic process is the area called the suprameatal triangle, suprameatal pit, mastoid fossa, foveola suprameatica, or Macewen's triangle, through which an instrument may be pushed into the mastoid antrum.
The inner surface of the mastoid portion of the temporal bone presents a deep, curved groove, the sigmoid sulcus, which lodges part of the transverse sinus; in it may be seen the opening of the mastoid foramen.
The proximal portion of the facial canal is termed the horizontal part.It commences at the introitus of facial canal at the distal end of the internal auditory meatus. The horizontal part is further subdivided into two crura: the proximal/medial [4] anteriolaterally [5] directed medial crus (or labyrinthine segment [5]), and the distal/lateral [4] posteriolaterally [5] directed lateral crus ...
There are two important foramina, or windows, two important fissures, or grooves, and one canal surrounding the globe in the orbit. There is a supraorbital foramen, an infraorbital foramen, a superior orbital fissure, an inferior orbital fissure and the optic canal, each of which contains structures that are crucial to normal eye functioning.
Schematic diagram of the human eye. It shows a horizontal section through the right eye. The eye is made up of three coats, or layers, enclosing various anatomical structures. The outermost layer, known as the fibrous tunic, is composed of the cornea and sclera, which provide shape to the eye and support the deeper structures.