Lecture 1 - The Skull Flashcards
What are the two parts of the skull called? and how many bones are in each?
- the neurocranium/braincase (8)
- the viscerocranium/facial skeleton (14)
How many bones does the skull consist of?
22
What are the 4 single bones and the 2 paired bones of the neurocranium?
Single:
- frontal
- occipital
- ethmoid
- sphenoid
Paired:
- parietal
- temporal
What are the 2 single bones and the 6 paired bones of the viscerocranium?
Single:
- vomer
- mandible
Paired:
- maxillae
- palatine bones
- nasal bones
- inferior nasal conchae
- zygomatic bones
- lacrimal bones
What are the functions of the neurocranium? (2)
- surrounds and protects brain
- articulates with the vertebral column
What is the main function of the viscerocranium?
- support and protects entrances to the digestive and respiratory tracts
How many accessory bones are in the skull? (for hearing and muscle attachment)
7
Neurocranium: What bones can be seen from the anterior view? (5)
- frontal bone
- parietal bones
- sphenoid bone
- temporal bones
- ethmoid bone
Neurocranium: What bones can be seen from the lateral view? (6)
- frontal bone
- parietal bones
- occipital bone
- sphenoid bone
- temporal bones
- ethmoid bone
What are the 4 external features of the temporal bone? (seen from the lateral view)
- external acoustic meatus
- mastoid process
- styloid process
- zygomatic process
Neurocranium: What bones can be seen from the superior view? (3)
- frontal bone
- parietal bones
- occipital bones
Neurocranium: What bones can be seen from the posterior view? (4)
- frontal bone
- parietal bones
- occipital bones
- temporal bones
Neurocranium: What bones can be seen from the inferior view? (6)
- sphenoid bone
- temporal bones
- zygomatic process
- styloid process
- mastoid process
- occipital bone
Neurocranium: What features can be seen from the inferior view? (3)
- mandibular fossa (articulation with mandible)
- foramen magnum (passage of spinal cord (feature of occipital bone))
- occipital condyle (articulation with teh atlas (C1) (feature of occipital bone)))
If you cut the skull in half in the horizontal plane, what bones could you see looking down from a superior view (loosing at the base of the skull) (5)
- frontal bone
- ethmoid bone
- sphenoid bone
- temporal bones
- occipital bones
what does the ethmoid bone form part of? (2)
- orbital wall
- nasal cavity/septum
What is the long part of the ethmoid bone that runs down called?
Perpendicular plate
Is concha single or plural?
Is conchae single or plural?
concha = single
conchae = plural
Features of the Ethmoid (3)
- Cristal galli (crest of the rooster)
- cribriform plate
- superior nasal concha
- middle nasal concha
Cristal galli
- perpendicular projection of the ethmoid bone
- acts as an acnhroing point for membranes surrounding th ebrain (meninges)
What passes through the cribriform plate of the ethmoid bone?
- branches of the cranial nerve I (olfactory nerve)
Features of the sphenoid bone
- form part of eye orbit and base of skull
- comprised of: body, 2 lesser wings and 2 greater wings (1 on each side fo the body)
- looks like an owl
- pterygoid processes
- ## sella turcia (turkish saddle)
What rests in the sella turcica?
the pituitary gland
Which is single, which is plural: foramen, foramina
single = foramen
plural = foramina
What does foramina allow?
the passage of nerves and blood vessels
Foramina of the sphenoid bone (7)
- inferior orbital fissure
- superior ortibal fissure
- optic canal
- foramen spinosum (smalled one)
- foramen rotundum
- foramen ovale
- foramen lacerum
Foramina of the temporal bone (3)
- carotid canal
- interal acoustic meatus
- jugular foramen
Foramina of the occipital bone (two)
- jugular foramen
- hypoglossal canal
Sutures of the skull (4)
- coronal
- sagittal
- squamous
- lambdoid
What two bones does coronal suture the seperate?
frontal bone and parietal bones
What two bones does the squamous suture seperate?
temporal bones and parietal bones
What two bones does the sagittal suture seperate?
the two parital bones
What two bones does the lambdoid suture seperate?
occipital bone and parietal bones
What are the 3 cranial fossae?
- anterior cranial fossa (frontal lobe)
- middle cranial fossa (temporal lobes)
- posterior cranial fossa (cerebellum)
What bones are part of the anterior cranial fossa?
- frontal, ethmoid, sphenoid bones
What bones are part of the temporal cranial fossa?
-sphenoid, temporal bones
What bones are part of the posterior cranial fossa?
- occipital, temporal bones
Viscerocranium: What bones can be seen from the lateral view? (5)
- zygomatic
- maxilla
- mandible
- nasal
- lacrimal
Viscerocranium: Features of the mandible (5)
- ramus
- body
- angle
- condylar process
- coronoid process
Viscerocranium: Features of the skull - lateral view (2)
- zygomatic arch (cheekbone)
- temporomandibular joint (TMJ)
Viscerocranium: Temporomandibular joint (TMJ)
- only moveable joint of the skull
- articulation between condylar process (mandible) and mandibular fossa (temporal bone)
Viscerocranium: What bones can be seen from the inferior view? (6)
- zygomatic bones
- zygomatic arch
- maxillae
- incisive foramen
- palatine bones
- vomer
Viscerocranium: the hard palate
- palatine process (of maxilla)
- palatine bones
Viscerocranium: when can you see the vomer
seen in lateral view when nasal septum is not removed
Accessory bones of the skull (2)
- ossicles
- ## hyoid bone
Ossicles (3)
- small bones involved in hearing
- housed in temporal bone
- 3 in each middle ear
What are the 3 ossicles
- malleus
- incus
- stapes
Hyoid bone
- “floating bone”
- located in neck
- important attachment site for tongue and muscles involved in swallowing
features of the hyoid bone
- lesser horn (cornu)
- greater horn (cornu)
body
