Chapter 10 Cranial Nerves Flashcards
Which nerves are sensory only?
1, 2, 8
What are mixed nerves?
sensory and motor neurons, most nerves
Which nerves are motor only?
none. No purely motor cranial nerves because they contain some sensory proprioception fibers
Olfactory nerve (CN I) function
VA neurons: sense of smell
carries olfactory (VA) impulses nasal cavity to olfactory bulbs of brain
SENSORY ONLY
Olfactory nerve type (CN I)
bipolar neuron
Optic nerve function (CN II)
SA neurons: vision
carry visual (SA) impulses from the retinae of the eyes to the optic chiasm of the brain
SENSORY ONLY
Optic nerve type (CN II)
bipolar neuron
Oculomotor nerve function (CN III)
SE, VE, SA proprioceptive neurons
muscles of eye; rotates eye; raises upper eyelid to open
Oculomotor nerve type (CN III)
Multipolar
Trochlear nerve function (CN IV)
Carries motor fibers to 1 muscle… superior oblique muscle to move eye through trochlea
Smallest cranial nerve; only nerve to arise from posterior aspect of brain
Trochlear nerve type (CN IV)
multipolar
SE neurons; SA proprioceptive
Trigeminal nerve function (CN V)
largest cranial nerve, principal sensory nerve of head; 3 subdivisions
Trigeminal nerve 3 subdivisions (CN V)
Ophthalamic n. - SA impulses from eye, eyelid, eyeball; pseudounipolar
Maxillary n. - SA impulses from cheek, upper lip, upper teeth, palate; pseudounipolar (EX.. senses hot chocolate or pizza on top of your mouth)
Mandibular n. - largest;
- SA impulses from around chin, lower lip, tongue/teeth; pseudounipolar
- SE impulses for mastication; multipolar
Abducens n. (CN VI)
SE neurons supply one muscle of eye, rotate eyeball laterally; multipolar
SA proprioceptive fibers
Facial N. (CN VII)
All 4 neurons!
VA: taste sensation; pseudounipolar
VE: lacrimal, sublingual, and submandibular glands
SE: muscles of facial expression and the stapedius m.
SA proprioceptive fibers
Vestibular Cochlear n. (CN VIII)
SA from cochlear part of internal ear (audition) and vestibular part of internal ear (balance and position)
bipolar
Glossopharyngeal n. (CN IX)
ALL 4 neurons
VA: taste sensations from posterior 1/3 of tongue, general sensation from back of tongue and pharyngeal region
VE: motor to parotid gland (salivation)
SA: area behind ear; pseudounipolar
SE: skeletal m. to pharynx
Vagus n. (CN X)
ALL 4 neurons; longest cranial nerve
VA: cervical thoracic and abdominal viscera (respiratory and digestive systems
VE - Involuntary muscles and glands in thoracic and abdominal cavities
SA: skin at back of ear
SE: Motor to muscles of larynx and pharynx
Accessory n. (CN XI)
SE: part of sternocleidomastoid muscle; supplies skeletal muscles of neck
Hypoglossal n. (CN XII)
SE: move tongue around
Which cranial nerves pass through jugular foramen?
CN 9, 10, 11
Which cranial nerve does not leave skull?
8
How many pairs of spinal nerves?
31
Plexses
network or bundle of vessels
cervical plexus
first 5 cervical n. (C1 to C5)
innervates skin of scalp, neck, superior aspect of shoulder, chest, neck m., diaphragm
brachial plexus
bundle of neurons that supply SUPERIOR limb (C5, C6, C7, C8, T1)
3 trunks of brachial plexus
- superior trunk C5+C6
- Middle trunk C7
- Inferior trunk C8+T1
Lumbosacral plexus
nerves that supply INFERIOR limbs
- lumbar plexus L1 to L4
- sacral plexus L4 to S4
Anterior root
carries motor fibers OUT OF anterior aspect of spinal chord
Posterior root
carries most sensory fibers INTO the spinal cord
sensory ganglia
- carries bodies of pseudounipolar neurons
- associated with most cranial nerves and on post. roots of spinal nerves
- NO synapses
- can interpret things so everything does not go to brain
ramus communican branch
pre and post ganglionic fibers in ANS; communicating branch
ganglia
groups of cell bodies in PNS
sympathetic trunk
two long nerve strands extend from base of skull to coccyx; one on each side of vertebral column
autonomic ganglia
- groups of cell bodies in PNS
- scattered in head, neck and trunk, along sympathetic trunk
- within walls of organs, along nerves and plexuses
- HAVE AT LEAST 1 SYNAPSE
3 types of autonomic ganglia
- sympathetic trunk (“paravertebral”) ganglia
- Named peripheral (“prevertebral”) ganglia
- terminal (intramural) ganglia
named ganglia assicated with which cranial nerves?
3,7,9,10
special senses
vision, audition, equilibrium, olfaction, gustation
general senses
touch, pressure, pain, heat, cold
photoreceptors
light, only in retina
thermoreceptors
temperature (some heat, some cold)
mechanoreceptors
detect pressure, touch, movement, stretch, vibration
chemoreceptors
taste buds and olfaction
nocioreceptors
pain
exteroreceptors
external environment
visceroceptors
visceral organ sensation (hunger/thirst, fatigue, pain)
proprioceptors
changes in position, balance, movement of muscles in jts, tendons, m. bellies and internal ear
