Nervous System
What does the ciliary muscle do when accommodation (focussing) in the eye occurs?
It contracts and the tension on the ciliary fibres increases making the eye lens less convex.
It relaxes and the tension on the ciliary fibres decreases allowing the eye lens to become more convex.
It contracts and the pull of the ciliary fibres decreases allowing the lens to become more convex.
It relaxes and the pull of the ciliary fibres increases to make the lens less convex.
It contracts and the pull of the ciliary fibres decreases allowing the lens to become more convex.
The ciliary muscle is doughnut-shaped with the lens in the “hole” and attached to the muscle by ciliary fibres (zonules). When the ciliary muscle contracts, it moves towards the lens which allows the ciliary fibres to reduce their tension so that the lens is stretched less. Hence it oozes to a more rounded shape.
It contracts and the pull of the ciliary fibres decreases allowing the lens to become more convex. The ciliary muscle is doughnut-shaped with the lens in the “hole” and attached to the muscle by ciliary fibres (zonules). When the ciliary muscle contracts, it moves towards the lens which allows the ciliary fibres to reduce their tension so that the lens is stretched less. Hence it oozes to a more rounded shape.
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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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