Skull Bones Flashcards
What are the immovable joints in the skull called?
- Sutures
What is the main function of the skull?
- to protect the brain
How many cranial bones are there?
- 8
How many facial bones are there?
- 14
What are the names of the eight cranial bones?
- Frontal bone
- Parietal bones (2)
- Temporal bones (2)
- Occipital bone
- Sphenoid bone
- Ethmoid bone
What does the frontal bone form?
- the forehead
- the anterior portion of the cranial cavity
- part of each orbit (eye socket)
What are some features of the frontal bone?
- supraorbital margin (2)
- supraorbital foramen (2)
- both are near the eyebrow or top of eye socket
What do the parietal bones form?
- the top and upper part of the sides of the head
- most of the superolateral portion of the cranial cavity
- the lower part of the sides of the head (temples)
- most of the inferolateral portion of the cranial cavity
What are some features of the temporal bones?
- Styloid process
- Mastoid process
- Stylomastoid foramen
- Carotid foramen
- Jugular foramen
- Zygomatic process
- Mandibular fossa
- External auditory meatus
- Internal auditory meatus
What are the three areas of the ear?
- inner ear
- middle ear
- outer ear
What is the scientific name for the “eardrum”?
- tympanic membrane
What is the opening between the middle ear and inner ear known as?
- the oval window
What are the three little bones in the ear?
- malleus
- incus
- stapes
What bone is attached to the tympanic membrane?
- the malleus
What bone is attached to a membrane covering the oval window?
- the stapes
What are the smallest bones in the body?
- auditory ossicles
What does the occipital bone form?
- The back of the head
- The posteroinferior portion of the cranial cavity
What are some features of the occipital bone?
- Foramen magnum
- Occipital condyle (2)
- External occipital protuberance
- Superior nuchal line (2)
- Inferior nuchal line (2)
What does the sphenoid bone form?
- The middle part of the inferior portion of the cranial cavity
- Part of each orbit
- Part of the nasal cavity
What does the word Sphenoid mean in greek?
- wedge
- “keystone” to the cranial floor since it articulates with all of the other cranial bones
What are some features of the Sphenoid bone?
- Body
- Sella turcica (“Turkish saddle”)
- Sphenoid sinus
- Greater wing (2)
- Lesser wing (2)
- Pterygoid process (4)
- Optic foramen (2)
- Superior orbital fissure (2)
- Foramen ovale (2)
- Foramen rotundum (2)
What does the ethmoid bone form?
- Part of the anteroinferior portion of the cranial floor
- Part of each orbit
- Part of the border of the nasal cavity
What does the word ethmoid mean in greek?
- “sieve-like”
- sponge-like in appearance with lots of small cavities
What are some features of the ethmoid bone?
- Cribiform plate
- Olfactory foramina
- Crista galli
- Perpendicular plate
- Lateral mass (2)
- Ethmoidal sinuses
- Superior nasal concha (2)
- Middle nasal concha (2)
