Neuro Flashcards
What does the frontal lobe control
Voluntary movement of contralateral side
Speech (dominant half)
Higher thought and personality
Function of the temporal lobe
Language comprehension (from auditory signals) Long term memory
Function of the parietal lobe
Sensory information - pain, pressure, taste, smell
Proprioception
Function of the occipital lobe
Visual language comprehension
Colour determination
What branches of the circle of Willis are given by the internal carotid
Anterior cerebral
Middle cerebral
Posterior communicating
What forms the posterior cerebral arteries
Basilar artery
What are the branches of the basilar artery
Pontine
Superior cerebellar
Anterior inferior cerebellar
What supplies the Circle of Willis and their relative contribution levels
Vertebral (20%) Internal Carotid (80%)
What supplies the Posterior inferior cerebellar artery
Vertebral Arteries
What area of the brain is involved in speech production
Broca’s area
What brain lesion would cause loss of right leg sensation and motor function
Left anterior cerebral artery
A patient is unable to form words, where might a lesion have occurred?
Middle cerebral of the dominant side (supplies broca’s area)
what are the unpaired sinuses of the brain
superior and inferior sagittal sinus
what is the name of the big central division of the brain and what connects the sides
longitudinal fissure
corpus callosum
What cranial nerve lesion causes left tongue deviation?
left hypoglossal
what is the falx cerebri
invagination of dura matter into the longitudinal fissure
what is the greater petrosal nerve
pre ganglionic lacrimal gland nerve
which part of the optic tract forms the optic chiasm and what happens to vision when it is severed?
medial retina, loss of peripheral vision
what is loss of lateral vision called?
bitemporal hemianopia
what is quadrantanopia
loss of a quarter of vision
usually contralateral and homonymous - unless damage is direct to retina
which part of the ear is fluid filled
inner ear
what is the order of the small ear bones?
malleus, incus, stapes (out to in)
how big is the tympanic membrane?
~1 cm
what prevents loud sounds rupturing the tympanic membrane
tensor tympani
which part of the ear is implicated in balance
semicircular canals
what is the oval window?
allows vibrations to pass into the cochlea from the middle ear bones
what is the role of the basal ganglia?
fine tunes movement through dampening of signaling
From lateral to medial what are the structures of the basal ganglia?
Putamen External Globus Pallidus Internal Globus Pallidus Caudate nucleus (superior) Substantia nigra (at the bottom)
What is the lentiform nucleus?
globus pallidus + putamen
Striatum is the term for what 2 structures?
Caudate nucleus + putamen
name a Hypokinetic disease and what changes bring it about
Parkinson’s - breakdown of basal ganglia direct pathways promoting only indirect inhibitory pathways
name and explain a hyperkinetic disorder
Huntington’s - indirect inhibition pathway breakdown - movement not fine tuned
what nerve palsy causes eyelid droop
III - oculomotor
also causes depression and abduction of eye (down out)
how many orders of neurons are there in ascending and descending spinal tracts
4 up 2 down
what are the ascending tracts
dorsal column medial lemniscus - cuneatus and gracilis
spinothalamic
spinocerebellar
what are the descending spinal tracts
corticospinal
corticobulbar
Extra pyramidal tracts
what is the difference between pyramidal and extrapyramidal tracts?
pyramidal do voluntary movement
extra do posture and muscle tone
where does the DCML decussate
in the medulla
what part of the DCML innervates the upper limbs
Fasciculus cuneatus
what information does the DCML carry
fine touch, vibration, proprioception
what does the anterior spinothalamic tract do
crude touch and pressure
what does the lateral spinothalamic do
pain and temperature
where does the spinothalamic decussate
Anterior white commissure of the spine
what spinocerebellar do tho?
proprioception of trunk and limbs
what are the divisions of spinocerebellar and their pathways
Dorsal - stays ipsilateral then decussates in the cerebellum to end up contralateral
Ventral - Crosses over in the spinal does not cross again so stays contralateral
corticospinal tract do what?
body muscles - pyramidal for voluntary movement
what is the path of the corticospinal tract
90% decussates at the medulla
10% stays ipsilateral
What tract lesion would cause facial paralysis
corticobulbar
does the corticobulbar tract decussate
yes but only 50% of fibers do
what are the 4 extra pyramidal tracts and which decussate and which don’t
vestibulospinal
reticulospinal
(both have i in them so they are ipsilateral)
rubrospinal and tectospinal - contralateral/decussates
hemisection of the spine causes loss of what on which side
ipsilateral loss of :
fine touch, vibration, proprioception, and movement
contralateral loss of:
crude touch, pain, and temperature
difference between alpha and gamma motor neurons
alpha is a choice
gamma is reflex
What prevents muscle overstretching
Intrafusal muscle fibers containing gamma motor neurons, type 1a, and type 2 sensory fibers for monitoring length and rate of change
type 1a cause contraction of muscle
type 2 cause relaxation of antagonist muscle
what type of sensory fibers are found on tendons
type 1b
what is the role of golgi tendon organs
prevent over contraction by inhibiting muscle and contracting antagonist
what is the myotatic reflex
Prevention of overstretching through type 1a fibers causing contraction and type 2 fibers causing relaxation of antagonist
what is responsible for inverse myotatic reflex
golgi tendon organs
what is the resting potential of axons
-70mV
what is the potential of the ECF
0mV
how is a negative resting potential achieved
active transport swaps 2K+ from out with 3Na+ from in leading to loss of positive ions
basal ganglia excitatory and inhibitory neurotransmitters
E: Glutamate
I: GABA
basic basal ganglia pathway centers around what
internal globus pallidus inhibiting the thalamus through GABA hyperpolarization
either inhibited by the striatum - direct
excited by inhibition of EGP causing subthalamic nuclei to stimulate IGP - indirect
