Cranial Nerves Flashcards
What is the central nervous system made up of?
Brain and spinal cord
Collections of cell bodies in CNS are called nuclei
What is the peripheral NS?
What are the 2 types of nerves found in the PNS
Nervous system outside the CNS
Cranial and spinal nerves
How many pairs of cranial nerves are there and what do they make connections between?
12 pairs and make connections between brain/brainstem to head/neck
How many pais of spinal nerves are there and what do they make connections between?
31 pairs of spinal nerves
Between the spinal cord and periphery(organs, glands,muscles,skin)
What are cell bodies in the PNS called?
Ganglia
What does the autonomic NS control?
Control viscera, smooth muscle, glands, heart
Beyond conscious control
Parts in CNS and PNS
Sympathetic and parasympathetic divisions
Fibres run in peripheral nerves, including some cranial nerves
What vertebral levels does the sympathetic trunk run from?
T1 to L2/3
Where does the parasympathetic NS run from?
From brainstem (via CNS) and sacral cord
What are the 12 cranial nerves?
Olfactory Optic Occulomotor Trochlear Trigeminal Abducens Facial Vestibulocochlear Glossopharyngeal Vagus Accessory Hypoglossal
What are the different types of nerve fibres?
Sensory
Motor
What are the types of sensory fibres?
Somatic-derived from somites eg, skin, muscle
Special-olfaction, visual, balance, taste, position & hearing
Autonomic-blood pressure, CO2 levels, light coming into the eye
What are the types of motor fibres?
Somatic eg, skin, muscles
Autonomic-smooth muscle, cardiac, adrenal glands
Which nerves are sensory, motor or both?
Some Say Money Matters But My Brother Says Big Brains Matter More
Which 4 nerves are parasympathetic nerves?
10, 9, 7, 3
Olfactory Fibres? Function? Origin/pathway? Extra?
Sensory
Sense of Smell
Olfactory bulb/epithemium —> cribriform plate —> uncus of temporal lobe
Commonly damaged in fractures to anterior cranial fossa
Optic Fibres? Function? Origin/pathway? Extra?
Sensory
Vision
Retina, optic canal, optic chiasm, lateral geniculate body, primary visual cortex (occipital lobe)
How to test the opthalmic nerve?
Test each nostril with a strong characteristic smell
How to test the optic nerve is working?
Visual fields
Pupil reflexes
Visual acuity
Fundoscopy (look into eye with intrument)
Occulomotor Fibres? Function? Origin/pathway? Extra?
Motor & Parasympathetic
Motor:Innervates medial, superior and inferior rectus, inferior oblique and levator palpabrae superioris
Parasympathetic: pupil constriction, accomodation, lacrimal gland
Carries parasympathetic fibres from the edinger-westphal nucleus, nerves exit at the junction between the midbrain and pons, close to posterior cerebral arteries, passes along wall of cavernous sinus, though superior orbital fissure
Pupil dilation is …
Pupil constriction is…
Sympathetic
Parasympathetic
How to test occulomotor nerves work?
Test eye movements
Test pupillary light reflex
Trochlear Fibres? Function? Origin/pathway? Extra?
Motor
Innervates superior oblique
Nuclei in midbrain, nerves exit dorsally, course anteriorly, along cavernous sinus, through superior orbital fissure
Damage to the trochlear will cause what?
Double vision as they look down
What are the 3 branches of the trigeminal?
Opthalmic
Maxillary
Mandibular
What is the trigeminal nerve attached to?
The pons
Opthalmic
Fibres?
Exits through?
Function?
Senory
Superior orbital fissure
Sensory from eye and upper face
Maxillary
Fibre?
Exits through?
Function?
Sensory
Foramen rotundum
Mandibular
Fibre?
Exits through?
Function?
Motor and sensory
Foramen ovale
Motor for mastication
General sensation to anterior 2/3 of tongue and inside cheek
Where do the trigeminal afferents meet?
At meckel’s cave
How to test trigeminal works?
Sesnation to face
Muscles of jaw
Jaw jerk
Corneal reflex
Abducens
Fibre?
Function?
Origin and pathway?
Motor
Innervates lateral rectus
Nuclei in pons, nerves exit at pontomedullary junction, through cavernous sinus, superior orbital fissure
