Neurophysiology Terms Flashcards
Auditory Nerve - function
sensory: cochlea (hearing)
sensory: vestibular apparatus (gravity, head position, movement)
relative refractory period (def)
time after absolute refractory period, when a large stimulus (only) can cause an AP
otolith (def)
layer of CaCO3 crystals on top of fluid layer in utricle & saccule, increase density & inertia for better response
paradoxical co-activation (def)
activation of both sympathetic and parasympathetic nervous systems in situations of intense conflict
Intrafusal fibers (def)
fibers in muscle spindles which cause afferent neurons to create a generator potential when stretched
functional motor unit (def)
alpha-motor-neuron plus the muscle fibers it innervates
Abducens Nerve - function
- motor: lateral eye movement
- connected to III Oculomotor by medial/longitudinal fasciculus (MLF)
electrotonus (def)
passive AP propagation, by +ve ion movement to more -ve areas (+ve enter through channels, -ve areas created by RMP); axial; by displacement of other +ve charges; dissipates over short distance because of leak channels
endolymph (def)
fluid inside membrane of vestibular apparatus; low [Na+], high [K+]
somatic (def)
(mostly) voluntary nerves, innervating skeletal muscles
hyperpolarization (def)
decrease in V_m
end-plate potential (EPP) (def)
signal at perimuscular membrane (motor end plate) of neuromuscular junction (NMJ)
Optic Nerve - function
sensory: vision
Glossopharyngeal Nerve - function
motor (voluntary): swallowing
motor (AUTONOMIC, parasympathetic): salivary glands
sensory: taste (front 1/3 of tongue)
sensory: CAROTID SINUS BARORECEPTOR
Kinocilium (def)
single large, stiff hair on top of hair cell, forced to bend by linked stereocilia
Active zones of NMJ pre-synaptic terminal (def)
rows of neurotransmitter vesicles aligned in rows above receptors on motor end-plate
Facial Nerve - function
motor (voluntary): facial expression
motor (AUTONOMIC, parasympathetic): lacrimal & salivary glands
sensory: taste (back 2/3s of tongue)
action potential (def)
Large, transmissible, ALL-OR-NOTHING signal
autonomic (def)
reflexive (non-voluntary) nerves, typically non-limb motor nerves
post-synaptic potential (PSP) (def)
temporary change in membrane potential at post-synaptic membrane, caused by neurotransmitter binding receptors on membrane
Vagus Nerve - function
motor (voluntary): pharynx - swallowing, larynx - phonation
motor (AUTONOMIC, parasympathetic): decrease heart rate, increase abdominal muscle secretion & motility
sensory: AORTIC BARO- and chemoRECEPTORS
sensory: GI tract
ion permeability/conductance (g_K, g_Na, etc) (def)
how easily an ion can cross a membrane
cupulla (def)
ridge at end of canals/loops of vestibular apparatus, extending into endolymph in ampulla (sways in fluid)
Accessory Nerve - function
motor (voluntary): swallowing - reflexive component
motor (voluntary): shoulder shrugging
Neuromuscular Junction post-synaptic terminal component(s)
motor end plate
Neuromuscular Junction pre-synaptic terminal component(s)
distal alpha-motor neuron, attached Schwann cell
perilymph (def)
fluid between bone and membrane of vestibular apparatus; high [Na+], low [K+]
Olfactory Nerve - function
sensory: smell
inhibitory post-synaptic potential (IPSP) (def)
PSP bringing V_m further from threshold
Hypoglossal Nerve - function
motor (voluntary): tongue
phasic receptor (def)
rapidly-adapting, exhibit on-off response (measures on/off in time & space)
absolute refractory period (def)
time immediately after AP, when the neuron is incapable of firing again
tonic receptor (def)
slowly-adapting, measure degree of stimulus (e.g. pressure, degree of joint stretch/flexion)
NMJ synaptic cleft location
between neuron ending and myocyte; contains basal lamina (hold the two together during movement)
generator potential (def)
GRADED sensory neuron depolarization, proportional to stimulus; transient, caused by external force
Trochlear Nerve - function
motor: eyeball movement
threshold (def)
voltage that causes all available Na+ channels to be open, causing an AP
sympathetic nervous system (def)
catabolic component of autonomic system
Oculomotor Nerve - function
motor (voluntary): medial eye movement
motor (AUTONOMIC, parasympathetic): constrict pupil, thicken lens
Cranial Nerve Names
Olfactory
Optic
Oculomotor
Trochlear
Trigeminal
Abducens
Facial
Auditory (Vestibulocochlear)
Glossopharyngeal
Vagus
Accessory
Hypoglossal
Trigeminal Nerve - function
motor (voluntary): mastication
sensory: touch/temperature/pain to face/head/mouth
available, re: gated ion channels (def)
activation gate closed, inactivation gate open; non-conducting but ready for depolarization; usual resting state
ampulla (def)
widening at end of canals/loops of vestibular apparatus
nerve (def)
bundle of axons, both sensory & motor, to & from the same location
efferent (def)
motor
depolarization (def)
increase in V_m
Stereocilia (def)
small hairs on top of hair cell, forced to bend by inertia of endolymph
afferent (def)
sensory
Nodes of Ranvier (def)
gaps between myelinated segments of neuron
Resting Membrane Potential (def)
normal voltage difference across a membrane (typically -70mV)
excitatory post-synaptic potential (EPSP) (def)
PSP bringing V_m closer to threshold
parasympathetic nervous system (def)
anabolic component of autonomic system
