Nervous System
When the human eye is accommodated to make the image of a distant object focus on the retina, which of the following is true? The ciliary muscles are:
Relaxed, the ciliary fibres are taut and the lens is nearly spherical.
Contracted, the ciliary fibres are slack and the lens is nearly spherical.
Contracted, the ciliary fibres are slack and the lens is thin.
Relaxed, the ciliary fibres are taut and the lens is thin.
Relaxed, the ciliary fibres are taut and the lens is thin.
To focus on a distant object, the lens must be pulled into a thin profile by the ciliary fibres being taut. This occurs when the ciliary muscles recedes from the lens as it relaxes.
Related posts
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
Leave a Reply