- squamous part (temporal squama)
- petrous part (petrous pyramid)
- tympanic part.
- mastoid part (usually considered a separate part but it is formed by both the squamous and petrous parts)
What are the four regions of the temporal bone?
- Petrous part of temporal bone.
- Squamous part of temporal bone.
- Mastoid part of temporal bone.
- Tympanic part of temporal bone.
- External acoustic meatus.
Which bone is above the temporal bone?
The tympanic antrum is bounded above by a thin plate of bone, the tegmen tympani, which separates it from the middle fossa of the base of the skull; below by the mastoid process; laterally by the squama just below the temporal line, and medially by the lateral semicircular canal of the internal ear which projects into its cavity.
What bones does the temporal bone articulate with?
The temporal bone articulates with the occipital, parietal, sphenoid, malar, and by a movable joint with the mandible. Occasionally the squamosal presents a process which articulates with the frontal. A fronto-squamosal suture is common in the skulls of the lower races of men, and is normal in the skulls of the chimpanzee, gorilla, and gibbon.
What are the main parts of a bone?
explain how bones are classified. list the five major parts of a long bone. epiphysis- part that forms a joint Metaphysis-connects epiphysis to diaphysis Diaphysis- shaft of the bone Articular cartilage- cartilage on the bone at the epiphysis to cushion the joint Medulary cavity- space containing yellow bone marrow.
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How many parts are there in the temporal bone?
The temporal bone itself is comprised of five constituent parts. The squamous, tympanic and petromastoid parts make up the majority of the bone, with the zygomatic and styloid processes projecting outwards.
Which bone is the site of origin of the temporalis muscle?
The lower part of the squamous bone is the site of origin of the temporalis muscle
What is the middle meningeal artery?
The middle meningeal artery (MMA) supplies the skull and the dura mater (the outer membranous layer covering the brain). It travels underneath the pterion, thus a fracture of the skull at the pterion can injure or completely lacerate the MMA.
What bone is the ear?
The Temporal Bone. The temporal bone contributes to the lower lateral walls of the skull. It contains the middle and inner portions of the ear, and is crossed by the majority of the cranial nerves. The lower portion of the bone articulates with the mandible, forming the temporomandibular joint of the jaw.
Which muscle attaches to the lateral surface of the zygomatic process?
The masseter muscles attaches some fibres to the lateral surface of the zygomatic process.
What part of the ear is crossed by the cranial nerves?
It contains the middle and inner portions of the ear, and is crossed by the majority of the cranial nerves. The lower portion of the bone articulates with the mandible, forming the temporomandibular joint of the jaw. In this article, we shall look at the different parts of the temporal bone, their articulations, and any clinical correlations.
What part of the ear is petrous?
The petrous part is pyramidal shaped, and lies at the base of temporal bone. It contains the inner ear.
How many parts are there in the temporal bone?
In anatomy, each temporal bone is composed of five parts: the squama, the petrous, mastoid, and tympanic parts, as well as the styloid process. 1 Here’s a quick breakdown:
What are temporal bones?
The temporal bones are paired bones that help make up the sides and base of the skull (cranium). This places them lateral—to the side of—the temporal lobes of the brain’s cerebral cortex, ensuring that the cranium is properly supported and protecting the important structures there. As such, blunt trauma or fracture of these bones can lead ...
What is the tympanic part of the ear?
Tympanic Part: The curved portion of bone beneath the squama and in front of the mastoid process, the tympanic part forms a major part of the external acoustic meatus, which is the pathway from outer to inner ear. Its middle portion contains the tympanic sulcus, a groove that attaches to the tympanic membrane, better known as the eardrum. At its rear surface, the tympanic part forms the rear boundary of the mandibular fossa, a groove which connects with the jaw bone. The outside surface is rough and attaches to the cartilage portion of the acoustic meatus, whereas its interior fuses with the petrous portion, just below the ear canal. Thin and sharp in its middle portion, it splits to enclose a portion of the styloid process (see below).
What part of the mandibular fossa connects with the jaw bone?
At its rear surface, the tympanic part forms the rear boundary of the mandibular fossa, a groove which connects with the jaw bone. The outside surface is rough and attaches to the cartilage portion of the acoustic meatus, whereas its interior fuses with the petrous portion, just below the ear canal.
Which bone connects the squama to the orbits?
The front end of the squama is serrated and connects with the zygomatic bone —one of two paired bones that form the cheeks and the sidewalls of the orbits (the openings where the eyeballs sit). The bottom end of this bone connects to the masseter, another major muscle for chewing. In addition, this part of the temporal bone is connected ...
Which bone attaches to the jaw bone?
Notably, the temporal bone attaches to the joint of the jaw bone—the temporomandibular joint —and is fused with other bones of the skull, including the occipital bone on the lower rear side, the parietal bone above that, the sphenoid bone on its front side, and the zygomatic (cheek) bone . Caspar Benson/Getty Images.
Which part of the temporal bone is rough?
Mastoid Part: Forming the rear part of the temporal bone, the mastoid part’s outer surface is rough and attaches to muscles that regulate the motion of eyebrows (occipitalis muscle) as well as those above the ear (superior auricular muscle).
What are the parts of a temporal bone?
Because of its shape, it is split into five different parts: Squamous portion or part. Petrous portion or part. Mastoid portion or part. Tympanic portion or part.
Where is the temporal bone located?
The temporal bone or os temporale is a paired, irregular bone and the thickest in the human body, located at the sides and base of the skull. It provides space for important cranial arteries, veins, and nerves. The os temporale also provides attachment points for numerous muscles. It joins or articulates with the occipital, parietal, sphenoid, ...
What is the inner surface of the temporal squama?
The inner surface of the temporal squama is convex. At the bottom of the squama, the zygomatic process of the temporal bone juts towards the cheekbone (zygoma), forming the posterior portion of the zygomatic arch. This zygomatic process is part of the squamous portion of the left and right temporal bones.
What is the back of the temporal bone called?
At the back of the temporal bone is the mastoid part. It contains special cells called mastoid air cells. These sometimes fill with fluid that can become infected. An infection here is called mastoiditis.
What is the petrous part of the skull?
The petrous part of the temporal bone or petrous temporal bone is part of the skull base, situated between the paired sphenoid bone and singular occipital bone. It has a pyramid shape with a base and an apex.
Where is the tympanic part?
The tympanic part sits just below the squama and in front of the mastoid part. It surrounds the external auditory canal and makes up part of the mandibular fossa of the temporal bone. The mandibular fossa contributes to the articulation between the mandible and the skull at the temporomandibular joint.
Which bone is the zygomatic process?
The zygomatic process of the temporal bone (red) Where the zygomatic process exits, two ridges are visible. These are the posterior and anterior roots. The posterior root follows a path towards the external auditory meatus. The anterior root, much thicker and shorter, ends in the articular tubercle.
What is the tympanic portion of the temporal bone?
The tympanic portion of the temporal bone includes the external auditory meatus. When looking into the external auditory meatus in a bony preparation, normally covered by the tympanic membrane, features of the medial wall of the tympanic cavity can be visualized; the fenestra vestibuli (oval window), which is covered by the footplate ...
Which bone is smooth and provides attachment for the temporalis fascia and muscle at the superior and inferior temporal lines?
Externally, the squamous portion of the temporal bone is smooth and provides attachment for the temporalis fascia and muscle at the superior and inferior temporal lines, respectively. The zygomatic process, which has an anterior and posterior root, extends anteriorly and articulates with the zygomatic bone.
Which bone has an impression for the sigmoid sinus?
On the cranial surface, the mastoid bone has an impression for the sigmoid sinus and a small foramen that usually transmits an emissary vein to the sinus. The petrous portion has an impression for the superior petrosal sinus, which drains blood from the cavernous sinus to the transverse sinus.
Which bones articulate with the zygomatic?
Each articulates with the zygomatic bone (zygomaticotemporal suture), sphenoid bone (sphenosquamosal suture), parietal bone (parietosquamous suture), and occipital bone (occipitomastoid suture). Understanding the anatomy of the temporal bone is critical to a number of open skull base approaches. A number of critical neurovascular structures, ...
What is the tympanic canal?
The tympanic canaliculus transmits the tympanic branch of CN IX and the inferior tympanic artery. The cochlear canaliculus transmits the perilymphatic duct and vein.
What is the temporal bone?
The temporal bone ( os temporale; L., the temple) forms portions of the sides and base of the skull. 1. 2. It is anatomically divided into four regions called the squamous, mastoid, temporal, and petrous parts.
Which part of the ear is the tympanic part?
The tympanic part lies anterior to the mastoid part and inferior to squamous part. It contains the external auditory meatus, a canal that leads to the tympanic membrane ( eardrum) and bones of the middle ear.
What is styloideus temporalis?
Styloid Process ( processus styloideus temporalis) is a narrow inferior extension from the bottom surface of the tympanic part of the temporal bone. It is an attachment point for two ligaments and three muscles that move the pharynx and larynx during the swallowing process.
What is the squamous part of the cranial wall?
Squamous part or squama ( pars squa-mosa: squama temporalis) is the smooth, thin, superior portion of the bone that forms the lower lateral cranial wall. It gives attachment to the temporalis muscle. [ Lateral view / Cranial floor view]
What is the petrous part of the skull?
The petrous part is a medial extension that forms the base of the skull between the sphenoid and occipital bones. It contains canals and receptors (inner ear) for the hearing and equilibrium systems.
Where is the meatus acusticus externus temporalis?
4. 5. External acoustic (auditory) meatus ( meatus acusticus externus temporalis) is a prominent canal (the ear canal) in the tympanic part of the temporal bone. It transmits sounds to the tympanic membrane (eardrum) in the middle ear. [ Lateral view / Inferior view] 1.
Where is the tympanic part located?
It is located inferior to squamous part and anterior to the mastoid part of the bone. [ Lateral view / Inferior view] 1. 2.
How many parts are there in the temporal bone?
Morphologically and developmentally, temporal bones are divided into four parts. The parts of the temporal bone are:
What is the temporal bone?
Temporal bones are two in number; situated at the sides and base of the skull: chief bone of the temporal region and each temporal bone contains the organs of hearing and equilibrium. The lower facial nerve and major vessels to and from the brain pivot the temporal bone.
What is the squamous tympanic fissure?
Squamous-tympanic fissure: lies medially between the articular part of the mandibular fossa and tympanic part of the temporal bones; divided by the projection into it of the lower edge of the downturned anterolateral portion of tegmen tympani of the petrous part of temporal bones into 2 parts.
What is the name of the air space in the temporal bone?
Several irregular air spaces are present in the mastoid part of the temporal bones which can be seen in a section; one large air space is known as Mastoid or Tympanic antrum; mastoid air cells are intercommunicating and they also communicate with middle car cavity (Tympanic cavity). 3.
What is the superior border of the temporal bones?
Posterior border: thick and serrated; articulates with inferior (Mastoid) border of the squamous part of the temporal bone s.
Which bone is the anterior inferior border?
Antero-inferior border: articulates with the greater wing of the sphenoid temporal bone. 2. Mastoid part. Mastoid part of temporal bones forms the posterior (posteroinferior) part of the temporal bones and is thicker than the squamous part.
What is the squamous part of the temporal bone?
The Squamous part of the temporal bones is thin, translucent, and expanded plate-like; forms the anterior and upper part of the bone.