Bones Of The Skull Flashcards
Cranial is made of how many bones and what are they?
Made of 8 bones
- Occipital (1 bone)
- Parietal (2 bones)
- Frontal (1 bone)
- Temporal (2 bones)
- Ethmoid (1 bone)
- Sphenoid (1 bone )
Facial is made of how many bones and what are they?
14 Facial
- Nasal (2 bones)
- Vomer (1 bone)
- Lacrimal (2 bones)
- Zygomatic(2 bones)
- Palatine (2 bones)
- Maxilla (2 bones)
- Mandible (1 bone)
- Inferior nasal concha (2 bones)
The cranial bones form what?
The cranial bones form a vault for the brain and facial bones
- giving origin to the muscles facial expression
- and providing buttress to protect the brain
The orbit is composed of how many bones and which bones?
- eye sockets ar the orbits.
- Composed of seven bones
1. Frontal
2. Ethmoid
3. Sphenoid
4. Lacrimal
5. Zygomatic
6. Palantine
7. Maxilla
The Orbit has how many fissures and canals?
The orbit has two fissures and one canal. it is home to the eye and related muscles, nerves and vessels. The most delicate of the skull bones is at the medial orbital wall. the external nose is largely cartilaginous and is therefore not part of the body skull except for the nasal bones.
What are the buttresses of the skull and what do they do?
- At certain sites of the skull, the bone is particularly thickened into pillars (buttresses)
- they maintain a strong resistance to forces imposed on it by transmitting forces away from the vulnerable orbits, nasal cavities, and brain, and there for resisting fracture
- three of the obvious are the superior, lateral and inferior orbital buttresses
- There are buttresses around the mouth (masticatory), at point of the chin (mental tubercle), and the back of the skull (occipital)
Name three occipital buttresses
-Superior, lateral and inferior orbital buttresses
formina
-numerous formina provide a passageway for cranial nerves ad blood vessels into and out of the interior of the cranium and skull.
Three paired formina in the vertical plane above and below the orbit and in the mandible, where are the exit sites?
These are exit sites for the supraorbital, infraorbital, and mental nerves that supply sensory fibers to the skin of the face. They are all cutaneous branches of the three divisions of the trigeminal nerve.
Zygomatic Arch
-Deep to that is the temporalis muscle and its strong fascial covering. this bony- musculo- fascial wall helps protect the middle meningeal artery (which rides in a groove on the internal surface of the temporal bone) following an impact on the side of the head.
What contributes to the nasal septum?
The vomer and perpendicular plate of the ethmoid contribute significantly to the nasal septum.
deviated septum
traumatic disruption of the nasal septum may result in a deviated septum, a condition that can make nasal breathing difficult.
paranasal sinuses
- bony cavities in the skull and here the large sphenoid sinus can be seen in the sphenoid bone.
- the pituitary gland fits in a saddle shaped sella turcica above the sphenoid sinus.
- on either side of the sella is a large sinus filled with venous blood( cavernous sinus)
The anterior cranial fossae support?
The anterior cranial fossae support the frontal lobes of the cerebum.
-olfactory tracts lie over the cribriform plates, through which pass the aolfactory nerves(sense smell)
Occipital Bone attachment?
-the large external surface of the occipital bone is a site of attachment for layers of posterior cervical musculature.
-The foramen manum transmits the lower brain stem/spinal cord. the large occiptial condyles articulate with facets of the atlas or first cervical vertebra. the muscular pharyngeal wall attaches around the posterior nasal apertures.
-
