Module 4.1 Skull Flashcards
Skull
22 bones
- cranium (8 bones)
- facial bones (14 bones)
Cranium
- protects brain
- 8 bones fitted tightly together in adults
Fontanelles
Aka soft spots
membranous region where certain bones are not completely formed in new borns
- allow bones of skull to compress during childbirth & expand to accommodate rapidly growing infant brain
- regions begin to close around 2 months but may last up to two years
Bones in Cranium
frontal
parietal
temporal
occipital
same names as lobes
Frontal bone
- one bone
- forms the forehead
Parietal Bones
- two, paired bones
- extend to the sides
Occipital Bone
curves to form the base of the skull
Temporal Bone
opening that leads to the middle ear
Sphenoid Bone
- completes the sides of the skull
- contributes to the floors &walls of the eye sockets
Ethmoid Bone
- lies in front of the sphenoid
- part of the orbital wall
- component of the nasal septum
*sphenoid & ethmoid bones lie largely inside the skull
Foramen Magnum
- large opening in occipital bone
- spinal cord passes it to become the brain stem
Sinuses
- air spaces lined by mucous -membrane in bones of cranium
- reduce weight of skull & give resonant sound to voice
Mastoid Sinuses
- drain into the middle ear
- 2 sinuses
Mastoiditis
- inflammation of the mastoid sinuses
- can lead to deafness
Sinusitis (sinus infection)
- soft tissues inside the sinuses become inflamed from virus, bacteria, or allergy
Foramina
Functions: passage for blood vessels, nerves, & spinal cord
Foramen Magnum
-passage of the spinal cord into the skull
Carotid Canal
opening of temporal bone for internal carotid artery
External Acoustic Meatus
- transmission of sound
- located in temporal bone
Mandible
- lower jaw
- only movable portion of the skull
- contains tooth sockets
- mandible and vomer are only non-paired bones of the facial skeleton
- THERE ARE 14 FACIAL BONES*
Maxillae
- upper jaw
- forms anterior portion of hard palate
- contains infraorbital foramen-
- contains tooth sockets
Zygomatic Bones
-cheekbone prominences
Nasal Bones
-bridge of the nose
Palatine Bones
-posterior portion of hard palate -floor of nasal cavity
Lacrimal Bone
- thin, scale like
- lies between ethmoid bone & maxillary bone
Vomer
- thin, flat
- joins w/perpendicular plate of ethmoid to form nasal septum
Inferior Nasal Conchae
bones located inferiorly to middle conchae
Middle & Superior Nasal Conchae
-formed from the grooves of the ethmoid bone
Nasal Conchae Function
- act to swirl the air as it is breathed in through the nasal passages
- helps warm & humidify air before it enters lower respiratory system
