Chapter 7 - Axial Skelly Flashcards
What does the cranial cavity enclose?
The brain
What are the orbits?
Eye sockets
What are the paranasal sinuses?
Air-filled spaces connected to nasal cavity
- frontal
- sphenoid
- ethmoidal
- maxillary
What are the functions of the paranasal sinuses?
Decrease skull weight
Resonating chambers
What is the job of your cranial bones?
To protect the brain
What are the two divisions of the cranium?
Calvaria (skullcap) and cranial base (cranial floor)
What are the three divisions of the cranial base?
- anterior cranial fossa (frontal lobe)
- middle cranial fossa (temporal lobe)
- posterior cranial fossa (cerebellum)
Describe the location of the frontal bone
Makes up the forehead
Roof of orbit
Anterior third of roof of cranial cavity
What skull bone is separate in infants but fuses to a single bone by adulthood?
Frontal bone
What is the glabella?
the smooth area above the root of nose
Describe the location of the parietal bones
Cranial roof and part of walls
What are the 4 largest sutures and where are they found?
- Sagittal: between parietal bones
- Coronal: anterior margin (frontal/parietal joint)
- Lambdoid: posterior margin (occipital/parietal joint)
- Squamous: lateral border (parietal/temporal joint)
Describe the location of the temporal bones?
Lateral wall and part of floor of cranial cavity
What are the four main parts of the temporal bones?
- Squamous
- Tympanic
- Mastoid
- Petrous
Describe the squamous part of the temporal bone and what features are found there
Flat/vertical
Encircled by squamous suture
Features: zygomatic process, mandibular fossa
Describe the tympanic part of the temporal bone and what features are found there
Ring that borders the ear canal
Features: external auditory meatus, styloid process
Describe the mastoid part of the temporal bone and what features are found there
Posterior portion
Features: mastoid process (air pockets), mastoid notch, stylomastoid foramen (Facial nerve)
Describe the petrous part of the temporal bone and what features are found there
Cranial floor - “little mtn. range”
Separates middle from posterior cranial fossa
Features: middle- and inner-ear cavities, internal auditory meatus, carotid canal, jugular foramen
Describe the location of the occipital bone?
Rear of skull and base
What is the major foramen found in the occipital bone and what goes through it?
Foramen Magnum
Spinal cord
What are some of the features of the occipital bone?
Foramen Magnum
Occipital condyle (knobs that allow skull to rest of vertebral column)
External occipital protuberance
Superior and inferior nuchal lines
Describe the sphenoid bone
Thick median body with outstretched wings
Describe the lesser wings of the sphenoid bone
Posterior margin of anterior cranial fossa
Posterior wall of orbit
Features: optic canal (optic nerve) - anterior to sella turcica
Describe the greater wings of the sphenoid bone
Approximately half of the middle cranial fossa
Lateral surface
What are some of the features fo the sphenoid bone?
Greater and lesser wings Superior orbital fissure (passage of nerves supplying the eye muscle, between greater/lesser wings) Body (sphenoid sinus) Sella turcica (pituitary gland) 3 major foramen: 1. Foramen rotundum 2. Foramen ovale 3. Foramen spinosum