L9.2 Skll and cranial nerve Flashcards
1
Q
Features of the skull bones
A
- Skull has 22 bones united at immobile joints call Sutures, grouped into
- Cranium
- Facial bones (Hangs off cranium)
- Mandible
2
Q
What is the roof and floor of the cranial cavity called?
A
- Roof = Cranial vault
- Floor = Cranial base
3
Q
Bones of the cranium (9)
A
- Frontal x2 (technically 1 bone, but suture separates it into 2)
- Parietal x2 (Green)
- Occipital x1 (Blue back part)
- Temporal x 2 (Orange - contain apparatus allowing us to hear)
- Sphenoid x 1 (Red)
- Ethomoid x 1 (Base of the frontal bone)
4
Q
Facial bones (14)
A
- Maxilla (purple) x2
- Zygomatic bone (orange) - forms the cheek bones x2
- Orbit bones: (inside the eye)
- Nasal bones x2
- Lacrimal bones x2
- Vomer x1
- Palatine bones x2
- INF conchae x2
- Mandible
5
Q
Different skull sutures
A
- Sagittal suture - down middle of skull
- Coronal suture - 2 parietal bones joins frontal bone
- Lambdoidal suture - joins 2 parietal bone with occipital bone
6
Q
Diagram of the Floor of the cranium
A
7
Q
ANT cranial fossa
A
- ANT- Frontal bone
- POS - Lesser wing of sphenoid (top wing)
- Floor
- Orbital plates of the frontal bone
- Cribiform plate of the ethmoid
8
Q
Middle cranial fossa
A
- ANT - Lesser wing of sphenoid
- POS - Petrous portion of temporal bone
- LAT
- Temporal bone
- Greater win of sphenoid
- Parietal bone
9
Q
POS cranial fossa
A
- Contents:
- Cerebellum
- Pons
- Medulla oblongata
- ANT - Petrous portion of the temporal bone
- Floor
- Basilar, condylar, squamour portions of the occipital bone
- Mastoid process of the temporal bone
10
Q
Features of the sphenoid bone
A
- Forms ANT and middle cranial fossa
- Connects orbits with cranial cavity
- Has a gap → allows V,A,N to travael through
11
Q
General features of the cranial nerves
A
- 12 paired nerves, somatic/visceral motor and sensory information to head
- Most cranial N originate from the brainstem
- Associated with cranial N 3-12 (1&2 found in CNS)
- Cranial N pass raustral to caudal (3 is above 4…)
- Cranial N 4 goes out in dorsal aspect
12
Q
1 - olfactory nerve
A
- Action: sense of smell
- Exit: Cribiform plate
- N → bulb → tract → brain
13
Q
2 - optic nerve
A
- Action: Vision
- Exit: Optic canal in sphenoid bone
14
Q
3 - Oculomotor
4 - Trochlear
6 - Abducent
A
- Nerves of ocular motion:
- Six extraocular muscles (controlled by 3 nerves)
- Action: Act in a coordinated fashion to move eyeball around
- Exit: Through superior orbital fissure (b/w lesser and greater wing of sphenoid)
15
Q
5 - trigeminal nerve
A
- Somatic sensory to face (major)
- ANT side of face - up to mid
- Motor to muscles of mastication
3 major branch exits
- V1 → Superior orbital fissure
- Opthalic division
- V2 → Foramen rotundum
- Maxillary division (Jaw to cheek area)
- V3 → Foramen ovale
- Mandibular division
16
Q
7 - facial nerve
A
- Action:
- Motor: Muscles of facial expression
- Visceral efferent (PS): Glands (lacrimal, sublingual glands)
- Visceral sensory (Taste to ANT 2/3 of tongue)
- Somatic sensory
- Exits: Internal acoustic meatus
17
Q
Muscles of the face
A
- Temporal
- Raising eyebrow and closing eyelid
- Zygomatic
- Cheeks
- Buccal
- Smiling
- Marginal mandibular
- Moves jaw
- Cervical
18
Q
8 - Vestibulocochlear
A
- Action: Hearing and balance (sensory)
- Exit: Internal acoustic meatus
- Petrus portion of the temporal bone
19
Q
9 - Glossopharyngeal N
A
- Action: (mostly sensory)
- Sensory from tongue (POS 1/3), pharynx, middle ear and carotid body
- Taste: POS 1/3 tongue
- Visceral motor: PNS to parotid
- Motor: Stylopharyngeus
- Exit: Jugular formen
21
Q
11 - spinal accessory N
A
- Action: Motor to sternomastoid and upper part of trapezius
- Exit: Spinal accessory nucleus in the upper 5-6 cervical spinal cord
- N enter cranium via foramen ovale
22
Q
12 - hypoglossal N
A
- Motor: muscles of the tongue
- Exit: Hypoglossal foramen
- Tongue points towards the direction of defective hypoglossal branch side
