The Skull (Study Guide) Flashcards
Sutures
Fixed immovable joints (synarthrodial), are exclusive to the skull
Skull
cranium or braincase
Calvaria
skull cap
Floor of the skull’s 3 divisions
- Anterior cranial fossa
- Posterior cranial fossa
- Middle cranial fossa
Base of the skull’s bony markings
- Foramen magnum
- mastoid
- styloid process
Total # of bones of the skull
22 irregular & flattened bones
29 with malleus (2), incus (2), stapes (2), and hyoid bone
8 Cranial Bones
Frontal (1) Parietal (2, paired) Occipital (1) Temporal (2) Ethmoid (1) Sphenoid (1)
Frontal Bone
- Unpaired cranial bone
- forms lower and posterior portion of the cranium
- Contains foramen magnum
- Undersurface= contains condyles for articulation of first cervical vertebrae
- Anterior to the foramen magnum (basilar portion)= contacts sphenoid bone
Parietal Bone
- Paired (2) cranial bone
- forms the roof of the cranium
- separated by the sagittal sutures
- separated from the frontal bone by the coronal suture
Occipital bone
- unpaired cranial bone
- forms lower and posterior portion of the cranium
- contains foramen magnum
- Undersurface= contains condyles for articulation of first cervical vertebrae
- Anterior to the foramen magnum (basilar portion) = contacts sphenoid bone
Temporal bone’s parts
- Squamous
- Petrous
- Mastoid
- Tympanic
- Styloid
Temporal Bone
Paired (2)
Forms lateral aspect of the skull
Contains 5 parts
Ethmoid Bone
- Unpaired cranial bone
- Contributes to facial skeleton
- Delicate
- Lies between the frontal bone and contributes to the wall of the orbit and nasal cavities and anterior aspect of the cranial base
Ethmoid Bone is posterior to the
lacrimal bone
Ethmoid bone contains
- the horizontal cribriform plate
- olfactory nerve emerges from the nasal cavity through these holes
Olfactory nerve is responsible form our…
sense of smell
Sphenoid Bone
-Unpaired (1)
-Butterfly shaped
-most complex bone of the skull
forms a portion of the floor and base of skull
-posterior to the ethmoid bone
- anterior to foramen magnum
Composition of Sphenoid bone
- Central body
- 2 sinuses
- 2 greater wings
- 2 lesser wings
- 2 Pterygoid processes or plates (medial and lateral)
Sphenoid spines
at the point where the greater wings join the body
form attachment of the veli palatini muscle of the soft palate
Sphenoid bone contains:
superior orbital fissure
Anterior of sphenoid is…
ethmoid bone
Sphenoid Bone comprises..
orbit of the eye
Sphenoid bone foramen
- two that carry CN V (5th cranial nerve)
- foramen rotundum carries the maxillary branch
- foramen ovale carries the mandibular branch
anterior of the sphenoid body forms…
the posterior of the nasal cavity
14 Facial Bones:
Mandible Maxillae (2) Nasal Bones (2) Palatine bones (2) Lacrimal bones (2) Zygomatic bones (2) Inferior conchae (2) Vomer
Mandible
Unpaired lower jaw largest bone of the face single bone in adults at birth, it is joined into 2 halves by a mental symphysis or mandibular symphasis...fibrous joint
Mental proturberance
triangular projection at the lower end of the mental symphasis that is the point of the chin
usually depressed in the middle
gives rise to 2 anterior projections or mental tubercles
mental foramen
2 holes in the chin that serves as an exit for nerves
Inner Surface: Mandible
mental spines located near:
symphysis
Inner Surface: Mandible:
alveolar arch:
the tooth bearing portion of the mandible (upper part)
