neuro extra Flashcards
Which nerve innervates the posterior 1/3 of the tongue for taste?
Glossopharyngeal nerve (IX)
which tract does motor
corticospinal
which tract is pain and temp
spinothalamic
which tract doesFINE TOUCH, VIBRATION,
PROPRIOCEPTION, 2-POINT
DISCRIMINATION
DCML
4 folds of dura mater
Falx cerebri
Falx cerebelli
Tentorium cerebelli
Diaphragma sellae
effects of UMN lesions
Hypertonia/spasticity
Hyperreflexia
+ve Babinski sign (plantar upgoing)
Pyramidal weakness (flexors > extensors in UL)
Ankle clonus
effects of LMN lesions
Hypotonia
Hyporeflexia
Muscle fasciculations (small involuntary twitching)
Muscle atrophy
A stroke of the right posterior cerebral artery would result in which visual defect?
Left homonymous hemianopia with macular sparing
what nerve is affected in wrist drop
radial
Which spinal tract transfers information regarding perception of self-movement and
body position of our lower limbs to the medulla oblongata?
Fasciculus Gracilis - DCML
What is the function of the Pia Mater and what cell type aids with this function?
Forms the blood brain barrier; Astrocytes
What is the resting membrane potential of a neuron?
-70mv
What is the definition of temporal summation?
Occurs when multiple subthreshold excitatory postsynaptic potentials (EPSPs) from one neuron
occur close enough in time to combine and trigger an action potential at the axon hillock (one to
one)
what is a motor unit
A single alpha motor neuron + all the muscle fibres it innervates
What is the definition of a muscle fasciculus?
A bundle of several muscle fibres
what is a muscle fibre
A thread-like structure of myofibrils
what is a myofibril
A basic unit of muscle containing actin and myosin filaments
what is a sarcomere
The functional unit of striated muscle
Which nerve type innervates intrafusal muscle fibres?
gamma motor neurones
Which cranial nerve is the afferent nerve of the carotid sinus?
glossopharyngeal
which part of ascending tracts control uppper and lower limb movements and where do they synapse rescpectively
fasciculus cunneatus = upper limb 1st order synapse in nucleus cunneatus
fasciculus gracilis = lowwer limb 1st order synapse in nucleus gracilis
2nd order synapse in thalamus
3rd orser travel to sensory cortex
what part of brain is associated with awareness of pain
prefrontal cortex
function of lentiform nucleus
putamen and globus pallidus - controlling voluntary movements and involved in memory
what occurs in damage to left meyers loop
contralateral homonymous superior quadrantanopia - upper right quadrant of both eyes
what CN is responsible for pupil reflex
3
what descending tract is responsible for fine control of hand movement
rubrospinal
what losses would one suffer with brown sequard syndrome
contralateral loss of pain crude touch pain and temp 1-2 lvls below lesion (spinothalamic)
ipsilateral hemiparesis and loss of of fine touch, vibration and propioception below lesion (DCML)
where does 1st order neuron of spinothalamic tract synapse in CNS
substantia gelatinosa of relaxed laminae
what % of corticospinal tract decussate forming contralateral lateral corticospinal tract
85
what muscle does trochlear innervate
superior oblique
what is efferent nerve of corneal reflex and what muscle is responsible
facial and orbicularis occuli
where does dcml decussate
medulla oblongata
where does spinothalamic tract decussate
spinal cord
posterior cerebellar tracts function
proprioceptive info from lower limbs to ipsilateral cerebellum
anterior cerebellar tract functiom
proprioceptive info from upper limbs to ipsilateral cerebellum (decussate twice)
the base of the basilar membrane is more sensitive to what freq of sound
high