Neurophys MCQs Flashcards
Which ONE of the following statements about the photoreceptors of the retina is CORRECT?
In the peripheral retina, rods are more common than cones.
With regard to the vestibular senses:
**The otolith organs can signal linear acceleration without significant adaptation.
Which of the following sensory parameters are topographically organised in their primary sensory cortex?
**B
The blood-brain barrier:
is produced by astrocytes and endothelial cells of the capillary wall.
Which ONE of the following statements about the functional organization of the brain is CORRECT?
The left cortical hemisphere generally controls the right side of the body.
Which ONE of the following statements about motor pathways is CORRECT?
The corticospinal tract crosses the midline.
With regard to image formation by the eye:
the cornea has greater optical power than the lens.
When preparing to reach down and pick up a bag, which brain area would be the final motor area to be activated before the movement begins?
Primary motor cortex
Which ONE of the following statements about the structure of the brain is CORRECT?
Connections between cortical areas are made by white matter tracts.
Which ONE of the following statements is CORRECT with regard to sensory receptors and afferents? Sensory receptors and afferents characterised as “rapidly adapting” or “phasic”:
generate more action potentials during changes in stimulus intensity than during steady stimulation.
With regard to the organisation of somatosensory cortex:
**The cortical representation of the hand is found near that of the face.
The traces below show action potential recordings from nine different peripheral afferent fibres. What was the likely movement of the stimulus relative to the finger?
**The stimulus was moved along the finger from tip to base.
Which ONE of the following statements about cerebro-spinal fluid (CSF) is CORRECT?
CSF is made at the choroid plexus.
Which ONE of the following statements is CORRECT with regard to the organisation of the spinal cord and peripheral nervous system?
Dorsal root ganglia contain the soma of sensory neurons.
With regard to spinal motor neurons:
The activity of an alpha motor neuron can be influenced by descending cortical input.
Choose the best option from the following table about spindle and Golgi tendon organ afferents.
A
Tactile sensory fibres with large receptive fields:
innervate body regions with low receptor densities.
In transducing mechanical energy into a neural signal, the cochlear hair cells:
utilise an influx of cations to depolarise the hair cell.
Choose the option that correctly assigns the roles of the outer, middle and inner ear.
**outer ear: modify sound based on location of source, middle ear: impedance matching, inner ear: sound transduction.
Which ONE of the following statements about the spinal cord is INCORRECT?
The spinal nerves have an organization where the sacral nerves tend to innervate the face, and the cervical nerves innervate the legs.
During normal voluntary muscle contraction (alpha and gamma co-activation):
**extrafusal fibres provide most of the contractile force.
A person who is unable to see things to the left side of where their gaze is directed has probably suffered damage to:
their right visual cortex (occipital lobe).
When a neuron adapts to a stimulus, this means that it:
generates action potentials at a lower rate.
Choose the CORRECT statement about the retina.
Rod photoreceptors outnumber cone photoreceptors throughout the retina except at the fovea.
Inhibitory synapses from a GABA-ergic neuron:
can prevent the post-synaptic neuron from reaching threshold.
Golgi tendon organs:
are in series with extrafusal muscle fibres.
In the myotatic reflex:
**the extrafusal muscle fibres contract due to 1A activity.
Which ONE of the following statements about optical defects is CORRECT?
Hyperopia is usually not corrected in adolescent patients.
Which ONE of the following statements is CORRECT with regard to the skin pain system?
*Nociceptive afferent fibres are slower to relay a signal to the spinal cord than the afferents for light touch on the fingers.
A person with normal vision except for anomalous trichromacy (red-green colour-blindness):
sees purple as grey.
Reflexes:
can be used to keep a limb in position.
The pitch of a pure tone:
determines where the travelling wave in the basilar membrane has its peak.
Shown in A and B are the action potentials generated in a single tactile afferent over 1s, under two different conditions. The alteration in response from A to B is due to a change in the applied stimulus.
The stimulus change that best accounts for the response change from A to B is:
**making the stimulus surface contact the skin with less force.
Which ONE of the following statements about cerebrospinal fluid is INCORRECT?
It fills axons and the central canal of the spinal cord.
Three neurons (designated N1, N2 and N3) synapse onto a common post-synaptic neuron. Simultaneous synaptic activity in these neurons has the following effects:
N1 and N2: post-synaptic action potential
N2: post-synaptic action potentia
N2 and N3: no post-synaptic action potential
Which of the following is the most likely conclusion?
**N1 is sub-threshold excitatory, N2 is supra-threshold excitatory, N3 is inhibitory.
Choose the CORRECT statement. The vestibular system:
uses the utricle and saccule to provide information about static head position.
The traces below show action potential recordings from nine different peripheral afferent fibres.
Which ONE of the following physical stimuli is most likely to have caused the observed pattern of activity?
An ice cube pressed gently against the skin.
