Nervous System
What is the effect of the movement of Na+ into a nerve cell followed very soon by the movement of K+ out of the nerve cell?
This establishes the resting membrane potential.
These movements are known as depolarisation and repolarisation.
These movements repolarise the cell.
It changes the membrane potential from about โ70 mV to about โ50 mV.
These movements are known as depolarisation and repolarisation.
When Na+ moves into a nerve cell, the cell depolarises (from โ70 mV to about +30 mV); when soon afterwards K+ moves out of the nerve cell, it repolarises (from +30 mV back to โ70 mV).
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In the spinal cord, the ascending tracts contain:A. White matter and transmit sensory information
B. White matter and transmit motor commands
C. Grey matter and transmit sensory information
D. Grey matter and transmit motor commands
Which sequence of ion movements describes the action potential?
A. Na+ move out of cell then K+ move in
B. K+ move in to cell then Na+ move out
C. K+ move out of cell then Na+ move in
D. Na+ move into cell then K+ move out
Which of the following substances is prevented from entering the brain by the blood-brain barrier?
A. Glucose
B. Nicotine
C. Pharmaceuticals
D. Alcohol
There are three ossicles in the middle ear. What are their names?
A. Malleus, stapedius, otolith
B. Cochlea, stapes, incus
C. Stapedius, ampulla, cochlea
D. Malleus, stapes, incus
The inner ear (or internal ear) may be described as a series of tubes. What are the tubes filled with?
A. Air
B. Perilymph
C. Endolymph
D. Perilymph and endolymph
What characterises a spinal reflex?
A. It involves rapid processing by the brain and a predictable response.
B. It is a predictable, unlearned and involuntary motor response.
C. It is a rapid, predictable, learned and involuntary motor response.
D. It involves stimulation of a motor neurone by a sensory neurone that originates within the CNS.
A multipolar neuron has more than one of what?
A. Dendrite attached to the cell body
B. Axon attached to the cell body
C. Synaptic terminal attached to the axon
D. Cell body
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