physiology ch 5 Flashcards
When another action potential could be generated if a greater than normal incoming stimulus is applied, the cell is in ______
Relative refractory period
What is the main function of the K+ leak channels in a typical neuron?
Builds most of the negative charge inside the cell
Alpha motor neurons release ______ which binds to _____ receptors on the motor endplate
acetylcholine, nicotinic
Which is triggered to CLOSE at the peak voltage of a typical neuronal action potential?
Voltage gated sodium channels
Which muscle would have the largest motor units?
Triceps brachii
When another action potential cannot be generated regardless of how great an incoming stimulus is, the cell is in ______.
absolute refractory period
Which muscle would have the largest motor units?
brachioradialis
The influx of _____ in a typical neuron will cause hyperpolarization, as the membrane becomes more negative than resting membrane potential.
chloride
Which type of neuron has the fastest conduction speed?
Type A alpha
Which is usually opened to allow + current into a typical sensory neuron receptor to summate to threshold?
pressure gated sodium channels
Which is triggered to CLOSE during the undershoot phase of a typical neuronal action potential?
Voltage gated potassium channels
Which occurs when 2 or more presynaptic inputs arrive at a post-synaptic cell in rapid succession (quickly, one right after the other) to allow sufficient inward current to reach threshold?
temporal summation
Which muscle would have the smallest motor units?
(hint; which contributes to the finest, most accurate motor activity)
flexor pollicis longus
At resting membrane potential, the typical neuronal cell membrane is MOST permeable to _____.
potassium
Which provides a lipid insulator to increase speed for saltatory conduction of nerve action potentials?
myelin
The influx of _____ in a typical neuron will cause depolarization towards threshold.
sodium
Which occurs during the undershoot of an action potential?
relative refractory period
Which muscle would have the largest motor units?
coracobrachialis
Which increases conduction velocity for a neuron?
Increasing the diameter of the nerve fiber
Which is located along the dendrites and soma of a typical motor neuron to allow influx of + current to summate to threshold?
ligand gated sodium channels
During saltatory conduction, the membrane only depolarizes at the ______.
Nodes of Ranvier
Which occurs during an action potential when the inactivation gates of the sodium channels are closed?
Absolute refractory period
During the repolarization phase of a neuron action potential, _____ is ______ the cell.
K+, leaving
Which muscle would have the smallest motor units?
(hint; which contributes to the finest, most accurate motor activity)
extensor indices
Which is triggered to OPEN at the peak voltage of a typical neuronal action potential?
Voltage gated potassium channels
Which 2 factors would increase the speed of nerve conduction?
increased diameter of nerve axon + increased amount of myelination
During the depolarization phase of a neuron action potential, _____ is ______ the cell
Na+, entering
Which occurs when 2 or more presynaptic inputs arrive at a post-synaptic cell simultaneously (at the same time) to allow sufficient inward current to reach threshold?
Spatial summation
Which is concentrated at the 1st node of Ranvier of a typical sensory neuron to trigger the depolarization phase of an action potential?
Voltage gated sodium channels
Which muscle would have the smallest motor units?
(hint; which contributes to the finest, most accurate motor activity)
Flexor digiti minimi
