Module 1 part 2. Flashcards
ophthalmic division of trigeminal nerve axons run from face to____ and convey____
pons via superior orbital fissure and convey sensory impulses from skin to scalp.
maxillary divisions of trigeminal nerve axons run from face to…. and convey….
pons via foramen rotundum and convey sensory impulses from nasal cavity mucosa.
mandibular division of trigeminal nerve axons pass through… and convey….
the skull via the foramen ovale and convey sensory impulses from anterior tongue.
the mandibular division of the trigeminal nerve axons are also a _____ branch which supply muscles of _____
motor; mastication
identify the cranial nerve:
- largest mixed cranial nerve, main sensory nerve to face, supply motor axons to muscles of mastication and DAMAGE produces loss of sensation and impaired chewing.
trigeminal nerve.
Tic douloureux (trigeminal neuralgia)
painful, sudden, spasmodic, involuntary contractions of the facial muscles supplied by the trigeminal nerve (pressure on nerve root).
abducen nerve are ____ axons that leave inferior ____ and pass through superior ____ fissure to eye. they provide ___ movement via ____ of the eyeball
motor; pons; orbital; eye; abduction.
facial nerves are ____ axons that emerge from the ____, enter the temporal bone via the internal ___ meatus and run within bone before emerging through _____ foramen which allow a motor branch to muscles of facial ____
mixed; pons; acoustic; stylomastoid; expression
what are the 5 branches of the facial nerve?
temporal, zygomatic, buccal, mandibular, cervical.
facial nerves supply motor axons to skeletal muscles of ____, except for ____ muscles which are served by cranial nerve V. they transmit ______ motor impulses to tear glands, nasal and salivary. they also convey _____ impulses from _____ buds of anterior tongue. damage produced _____ facial muscles and disturbed taste (Missing sweet, salty, umami)
face, chewing; parasympathetic, sensory; taste; sagging.
Bell’s Palsy…
temporary paralysis of the seventh cranial nerve (facial) that cause paralysis only one the affected side of the face.
Vestibulocochlear are _______ axons arising from ______ (cochlea nerves) & equilibrium apparatus within inner ear of ______ bone. it passes through the internal _______ meatus to enter the brainstem and pons-medulla border
sensory; hearing; temporal; acoustic.
Damage to vestibulocochelar nerve causes
deafness, dizziness, nausea, loss of balance and nystagmus (rapid eye involuntary movement)
Transverse temporal gyrus (inside lateral fissure)
primary auditory cortex.
auditory pathway to primary auditory cortex
stimulation of inner hair cell - superior olivary nucleus - inferior colliculus - thalamus - transverse temporal gyrus.
unilateral damage to primary auditory cortex =
hearing loss
bilateral damage =
cortical deafness
glossopharyngeal nerve are _____ nerves who’s axons emerge from the ______ and leave the skull through ______ foramen.
mixed; medulla; jugular.
glossopharyngeal nerve supply _____ axons to a _____ muscle, they also provide ________ motor axons to parotid _______ gland
motor; pharyngeal; parasympathetic; salivary
glossopharyngeal nerve sensory axons conduct _____ and general sensory impulses form ______ and posterior tongue. it also conducts sensory impulses from ______ in the carotid body and _______ receptors of carotid sinus
taste; pharynx; chemoreceptors; pressure.
swallowing, salivation, gagging sensations and control of blood pressure and respiration encapsulate what nerve?
glossopharyngeal nerve.
damage to glossopharyngeal nerve results in…..
loss of bitter and sour taste and impaired swallowing.
the vagus nerve are _____ nerves that emerge from _____ and pass through the skull via _____ foramen, descend through neck region into thorax and ______
mixed; medulla; jugular; abdomen.
vagus nerve supply ___ axons to skeletal muscles of pharynx and ______. parasympathetic motor fibres supply heart, ____ and abdomen viscera. it also supplies _____ impulses from thoracic and _____ viscera, transmitting sensory impulses from _______ in the carotid and aortic bodies and _____ receptors of carotid sinus.
motor; larynx; lungs; sensory; abdomen; chemoreceptors; pressure.
what is the only cranial nerve extending beyond the head?
vagus nerve
majority of vagus nerve axons are _____. vagus nerve provide swallowing and _____ and regulate activity of major viscera. damage to the vagus nerve causes loss of _____, impaired swallowing and digestive mobility
parasympathetic; speech; voice.
accessory nerve are _____ axons which arise by a series of roots form ______, exit from skull via ______ canal to tongue - axons emerge between the ______ and the olive
motor; medulla; hypoglossal; pyramid
accessory nerve cranial root joins axons of ______ nerve to supply motor axons to _____ /pharynx and soft palate
vagus; larynx.
spinal root supplies motor axons to trapezius and therefore provide, head, _____ and shoulder movement
neck
hypoglossal nerve are _____ axons which arise by a series of roots from the ____, exit from the skull via ______ canal to tongue - axons emerge between the pyramid and ______
motor; medulla; hypoglossal; olive.
hypoglossal nerve supplies ______ motor axons to muscles of ______ which provide tongue movements of speech, food manipulation and swallowing. damage causes difficulties in speech and ______
somatic; tongue; swallowing.
the cerebellum is located in the….. and below the …….
posterior cranial fossa - below the tentorium cerebelli.
the cerebellum consists of cortex, white matter and deep _______. highly orientated towards _____ integration but does not give rise to ______ sensory perceptions.
nuclei; sensory; conscious.
the cerebellum is mainly concerned with……
synchronised, precise movement, control of muscle tone and balance.
synergistic multi-jointed limb movement refers to what region of the brain and what movement?
cerebellum - synchronised precise movement e.g., throwing a ball.
external cerebellum contains posterior and inferior ______ with a _____ (Midline worm structure) that separates the cerebellar hemispheres. within each lobe, there is densely packed grey matter called _____. the fissure in the middle of the midline structure is called the ______ _______ _____ which contains a fold of dura mater called falx ______
lobes; vermis; folia; posterior cerebellar incisure; cerebelli.
folia of cerebellum
- cortical ridges
- most transversely orientated
- divide the cerebellum into lobes or lobules.
primary fissure of cerebellum
separates the anterior and posterior lobes of the cerebellum in each hemisphere.
the anterior and posterior lobes do what?
co-ordinate movement.
what are the three lobes of the cerebellum?
anterior, posterior, floccuolonodular.
floccuolonodular lobe of cerebellum is responsible for what?
balance
the posterolateral fissure
separates the floccuolonodular lobe from the posterior lobe from cerebrum.
the floccuolonodular lobe lies inferior to what?
inferior cerebellar peduncle.
lateral zone of cerebellum
cerebro-cerebellum
- this is the lateral portions of the anterior and posterior lobes. directly next to paravermal zones.
spinocerebellum
the uppermost part of the cerebellum, consisting mostly of the vermis and intermediate zone - involved in proprioceptive information and error connections in body movements.
cerebrocerebellum
the lowermost part of the cerebellum, consisting especially of the lateral zone part of each cerebellar hemisphere - involved in movement and learning/ visually guided movements.
the cerebrocerebellum receives input from the _____ and cerebral cortex with output tot the _____ and the red nucleus
pons; thalamus.
vestibulocerebellum
the middle portion of the cerebellum, between the spinocerebellum and cerebrocerebellum and consisting of the nodule and the floccuolonodular lobe - involved in controlling balance and ocular reflexes.
the vestibulocerebellum receives from the ______ system and sends outputs back to the vestibular ______
vestibular; nuclei.
arbor vitae
white matter of cerebellum
deep cerebellar nuclei lie…
within the white matter.
deep cerebellar nuclei contain 4 nuclei….
fastigial, globose, emboliform, dentate.
fastigial nucleus of the deep nuclei of the cerebellum
a deep cerebellar nucleus; involved in the control of movement by the reticulospinal and vestibulospinal tracts - deep cerebellar tracts to which the vermis projects.
interposed nuclei (globose + emboliform) of the deep nuclei of the cerebellum
a set of deep cerebellar nuclei: involved in the control of the rubrospinal system - associated with the intermediate zone
dentate nucleus of the deep nuclei of the cerebellum
a deep cerebellar nucleus; involved in the control of rapid skilled movements by the corticospinal and rubrospinal systems - associated with the lateral zone.
cerebellar cortex layers
molecular layer
cell layer
granule cell layer.
molecular layer of cerebellar cortex
most superficial
contains unmyelinated axons and dendrites of various cerebellar neurons.
purkinje fibres of cerebellar cortex
single layer of neurons with dendrites that extend into the molecular layer, axons synapse with deep cerebellar nuclei
granule cell layer
cells send axons to form parallel fibres in the outermost, or molecular layer.
granule cells in cerebellum
mossy fibres use these to excite purkinje cells. processes extend into the molecular layer and run as parallel fibres.
cerebellar cortex circuitry has two main inputs….
mossy fibres, climbing fibres
moss fibres axons extend from ….. and convey……
spinal cord or brainstem and convey motor and sensory input.
mossy fibres form______ synapses with granule neurons in the cerebellar cortex
excitatory
the granule neurons send their axons as a parallel fibre to form excitatory synapses with the _______ neurons; therefore these neurons have _______ innervation with purkinje fibres.
purkinje; indirect.
climbing fibres axons extend from …… and convey……
inferior olivary nucleus and convey proprioceptive input.
climbing axons form _____ synapses directly with ______ fibres (1 climbing axon = 1 purkinje cell)
excitatory; purkinje.
what is the sole output neuron of the cerebral cortex?
purkinje neurons.
spinocerebellar circuit (vermal/median zone)
fastigial nucleus receives somatosensory information from vermal cerebellar cortex and trunk - input to vestibular nuclei and reticular formation
- medial descending tracts which controls posture and axial muscles in trunk.
spinocerebellar circuit (intermediate zone)
interposed nuclei receive somatosensory information from intermediate cerebellar cortex and limbs
- input to the red nucleus
- lateral descending tracts which control accuracy of limb movements.
cerebrocerebellar circuit (lateral zone)
dentate nucleus receives sensorimotor information from lateral cerebellar cortex, cerebral cortex and pons
- input to the ventrolateral thalamus and red nucleus
- controls multi-jointed movements of limbs and contributed to motor planning
vestibulocerebellar circuit (floccuolonodular lobe)
floccuolonodular lobe receives vestibular information from the vestibular system - input to the vestibular nuclei
- controls balance.
inferior cerebellar peduncle
connects medulla to cerebellum - conveys sensory information to cerebellum, from muscle proprioceptors throughout body along with vestibular nuclei of brainstem
- connects both afferent and efferent axons
middle cerebellar peduncle
information from pons to the cerebellum - contains only afferent axons (crossed axons from contralateral pontine nuclei)
superior cerebellar peduncle
information from midbrain to the cerebellum - formed by axons that arise from deep cerebellar nuclei (main efferent pathway)
- crossed fibres ascend and either terminate at red nucleus or thalamus.
each cerebellar hemisphere exerts its influence primarily on the ______ half of the body
ipsilateral
cerebellar dysfunction
intention tremor
dysmetria
muscle hypotonia -> pendular knee reflex (persistent swinging movement of the limb after eliciting the DTF, >4 swings is abnormal)
nystagmus (rhythmic oscillation of the eyes) is associated with dysfunction in what region of the brain?
cerebellum
general senses
temperature, pain, touch, pressure, vibration, proprioception
general senses are detected by ____ receptors (nerve endings) and project to the somatosensory cortex (Post-central gyrus of parietal lobe)
simple
sensory receptors are classified by…..
the type of stimulus detected, body location and their structure and complexity.
exteroceptors
respond to stimuli arising outside the body. receptors in the skin for touch, pressure, pain and temperature. most special sense for organs.
interoceptors
monitor visceral organs and functions (chemical changes)
proprioceptors
sensory receptors, located in the muscles and joints, that provide information about body position and movement.
complex receptors of the special senses
special sense organs (vision, hearing, equilibrium, smell, taste)
free nerve endings
present dendrites forming small swellings - pain and temperature
- respond to light touch
e. g., free nerve endings, tactile disks, hair receptors.
encapsulated nerve endings
sensory neuron dendrites enclosed in a connective tissue capsule
joint kinesthetic receptors
proprioceptors that monitor joint position and motion - contributes to conscious proprioception.
free nerve ending function
detect pain and temperature.
tactile disk function
respond to light touch
tactile hair function
respond to light touch
pacinian corpuscles.
respond to deep pressure and vibration
Meissner’s corpuscles
light touch
Ruffini endings
respond to stretch.
dorsal column - medial lemniscal pathway
transmits sensory impulses from general sensory receptors of skin and proprioceptors to opposite side of somatosensory cortex
gracile tracts - carries impulses from lower limb and inferior body trunk
cuneate tracts - transmits afferent impulses from upper limbs, trunk and neck.
dorsal column pathway
first order neuron synapses in dorsal root ganglion (sensory receptor), second order neuron synapse in medulla (nuclei gracilis and cuneate and decussation)
- heading to the thalamus where third order neuron synapses via medial lemiscus/passes through internal capsule to post-central gyrus.
medial lemniscus
the somatosensory pathway between the dorsal column nuclei and the ventral posterior nucleus of the thalamus.
lateral spinothalamic pathway
pain and temperature - 1st order neuron synapses in dorsal root ganglion, decussation at spinal cord via 2nd order neuron and synapses in brain stem - 3rd order neuron carries to thalamus where it synapses, 3rd order neuron continues via internal capsule.
anterior spinothalamic pathway
crude touch and pressure - 1st neuron synapses in dorsal root ganglion where decussation of 2nd order neuron occurs in the spinal cord, synapse onto thalamus where 3rd order neuron continues via internal capsule.
spinocerebellar tracts
carry proprioceptive inputs to the cerebellum - do not contribute to conscious sensation
spinocerebellar pathway
no decussation and no 3rd order neuron - ascends via inferior cerebellar peduncle in cerebellum.
