skull & cranial nerves Flashcards
1
Q
The cranium
A
Bones that form the skeleton of the head
- neurocranium- houses brain
a. calvaria (skullcap)
b. cranial base (basicranium) - viscerocranium- facial bones that form:
a. orbits
b. nasal cavities
c. upper jaw
d. lower jaw (mandible)
2
Q
Neurocranium consist of 6 parts and subparts
A
- frontal
- parietal (2)
- temporal (2)
- mastoid process
- styloid process
- external acoustic meatus
- occipital
- external occipital protuberance
- sphenoid
- ethmoid
3
Q
sutures of neurocranium
A
- coronal- frontal & parietal
- lambdoid- parietal & occipital
- sagittal- R & L parietal
- squamous- parietal & temporal
4
Q
intersections of cranial sutures
A
- bregma- sagittal & coronal
- lambda- lambdoid & sagittal
- Pterion- frontal, parietal, temporal, sphenoid
- asterion- parietal, occipital, temporal
- nasion- frontal & nasal bones
5
Q
Other landmarks
- Glabella
- Vertex
- Inion
A
- Glabella-most anterior part of forehead
- Vertex- superior most point of neurocranium
- Inion- most prominent point of external occipital protuberance
6
Q
Cranial Base & associated holes in bones
A
- Anterior fossa
- cribriform plate (ethmoid) - Middle fossa
- optic foramen/ canal; sphenoid
- superior orbital fissure; sphenoid
- foramen rotundum; sphenoid
- foramen ovale; sphenoid
- foramen spinosum; sphenoid
- foramen lacerum; sphenoid - Posterior fossa
- internal acoustic meatus; temporal
- jugular foramen; btw temporal & occipital
- hypoglossal canal; occipital
- foramen magnum; occipital
7
Q
sphenoid bone
A
- the sphenoid & ethmoid bones form part of anterior cranial fossa, along with the frontal bone
- sphenoid also comprises the floor of the middle cranial fossa
- it is a key bone in cranial skeleton
- it articulates with 8 bones
- has central body, 2 wings laterally and 2 processes inferiorly
- the sella turcica holds the pituitary gland (hypophysis) within it.
8
Q
Viscerocranium contents
A
- lacrimal (2)
- nasal (2)
- maxillae (2)
- zygomatic (2)
- palatine (2)
- inferior nasal conchae (2)
- mandible
- vomer
9
Q
other important holes in the face
A
- supraorbital notch/foramen (frontal)
- infraorbital foramen (maxilla)
- mental foramen (mandible)
10
Q
CNS & PNS
- sensory (afferent): somatic/general, visceral
- motor (efferent): somatic motor, branchial motor, visceral motor
A
CNS- brain & spinal cord
PNS- sensory & motor neurons, clusters of neurons called ganglia and nerves connecting to the CNS
Sensory (afferent-going from external stimulants to the brain)
- somatic sensory (general)
- touch, pain, pressure, temperature (skin)
- proprioception (muscles, tendons, joints)
- special sensory: hearing, balance, vision, olfaction - visceral sensory (parasympathetic/sympathetic)
- reflex or pain sensatins from viscera, glands, blood vessels
- special sensory: taste
Motor (efferent- going from cranial/spinal nerves to organs)
- somatic motor
- innervation of skeletal muscles (except pharyngeal arch derivatives) - Branchial motor
- innervation of pharyngeal arch muscles - visceral motor (para/sympathetic)
- innervation of smooth muscles, cardiac muscle, glands
11
Q
overview of cranial nerves
A
- nerves originating from brain or brainstem and exiting through foramina or fissures in the cranium
- 12 pairs (CNI-XII) anterior to posterior
- variously carrying nerve fibers for:
1. somatic motor- movement of eyes, mastication, deglutition, respiration, vocalization, facial expression
2. general sensory -pain, pressure, temperature to tissues
3. special sensory- olfaction, vision, gustation, audition, equilibrium
4. parasympathetic motor- to lacrimal, salivary, mucous glands, smooth muscles of eye
12
Q
List the 12 cranial nerves
A
CN I- olfactory nerves CN II- optic nerve CN III- oculomotor nerve CN IV- trochlear nerve CN V- trigeminal nerve CN VI- abducent nerve CN VII- facial nerve CN VIII- vestibulocochlear nerve CN IX- glossopharyngeal nerve CN X- vagus nerve CN XI- accessory nerve CN XII- hypoglossal nerve
13
Q
cranial nerves and its location
A
- foramina of cribriform plate- CN I olfactory
- optic canal- CN II optic
- superior orbital fissure
- CN III oculomotor
- CN IV trochlear
- CN V1 opthalmic
- CN VI abducent - foramen rotundum- CN V2 maxillary
- foramen ovale- V3 mandibular
- internal acoustic meatus
- CN VII facial
- CN VIII vestibulocochlear - jugular foramen
- CN IX glossopharyngeal
- CN X vagus
- CN XI acessory - hypoglossal canal- CN XII hypoglossal
14
Q
CN I
- function-
- innervates-
- cranial exit-
A
Olfactory n.
- function- special sensory smell
- innervates- olfactory epithelium of superior nasal cavity
- cranial exit- cribriform plate of ethmoid
15
Q
CN II
- function-
- innervates-
- cranial exit-
- Damage to:
a. optic n.-
b. optic tract-
c. optic chiasm-
A
CN II- optic n.
- function-special sensory vision
- innervates-retina of the eye
- cranial exit-optic foramen; sphenoid bone
- Damage to:
a. optic n.- blindness of one eye (anopsia)
b. optic tract- loss of visual field on opposite side (homonymous hemianopsia)
c. optic chiasm- loss of peripheral visual fields (bitemporal hemianopsia, tunnel vision)