Term
A person with normal vision except for anomalous trichromacy (red-green colour-blindness):
A. sees blue as grey.
B. sees red and green as grey.
C. has blurry vision.
D. sees purple as grey.
E. sees yellow as blue. |
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Definition
Answer: D
With normal vision, purple is red and blue together without green, whereas grey is red, green and blue all together. If your red and green sense is the same, then there is no distinction between purple and grey for you. |
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Term
In transducing mechanical energy into a neural signal, the cochlear hair cells:
A. utilise ligand-gated channels near the apical border of the cell.
B. employ stereocilia that allow a single hair cell to combine the sound signals from the two ears.
C. utilise an influx of cations to depolarise the hair cell.
D. receive a chemical signal from the tectorial membrane.
E. have the same response to a forwards deflection of the stereocilia as to a backwards deflection. |
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Definition
Answer: C
In this case K+ will be the major cation contributor because of the high concentration of K+ in endolymph and the big driving potential. |
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Term
During normal voluntary muscle contraction (alpha and gamma co-activation):
A. intrafusal muscle fibres shorten while extrafusal fibres do not.
B. gamma motor neurons activate the alpha motor neurons.
C. extrafusal fibres provide most of the contractile force.
D. extrafusal muscle fibres shorten while intrafusal fibres do not.
E. contraction of the intrafusal muscle fibres weakens the stretch reflex. |
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Definition
Answer: C
Intrafusal fibres regulate the spindle activity. |
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Term
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?
A. N1 is sub-threshold excitatory, N2 is supra-threshold excitatory, N3 is inhibitory.
B. N1 is inhibitory, N2 is supra-threshold excitatory, N3 is sub-threshold excitatory.
C. N1 is sub-threshold excitatory, N2 is sub-threshold excitatory, N3 is inhibitory.
D. N1 is inhibitory, N2 is sub-threshold excitatory, N3 is sub-threshold excitatory.
E. N1 is supra-threshold excitatory, N2 is sub-threshold excitatory, N3 is inhibitory. |
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Definition
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Term
In the myotatic reflex:
A. the intrafusal muscle fibres contract due to 1B activity.
B. the extrafusal muscle fibres relax due to 1A activity.
C. the extrafusal muscle fibres contract due to 1A activity.
D. the 1B afferents increase their firing rate in response to increased muscle length.
E. the 1A afferents increase their firing rate in response to increased muscle tension. |
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Definition
Answer: C
This is the reflex contraction. |
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Term
Which of the following sensory parameters are topographically organised in their primary sensory cortex?
[image] |
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Definition
Answer: B
Topographically means ‘map-like’ and generally these parameters will be organised like that in the periphery and in the primary sensory cortex. |
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Term
Golgi tendon organs:
A. respond primarily to muscle length.
B. are in parallel with intrafusal muscle fibres.
C. are rapidly adapting receptors.
D. are in series with extrafusal muscle fibres.
E. cause mono-synaptic excitation of alpha motoneurons. |
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Definition
Answer: D
The force of the muscle is transmitted through the tendon, and detected by the Golgi tendon organ. |
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Term
[image]
A. An ice cube pressed gently against the skin.
B. The sharp edge of a knife pressed firmly against the skin.
C. A flat piece of plastic pressed gently against the skin.
D. A candle flame held near the skin.
E. The blunt end of a pencil pressed firmly against the skin. |
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Definition
Answer: A
An ice cube pressed gently against the skin would explain the cold and tactile afferent activity. |
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Term
Which ONE of the following statements about motor pathways is CORRECT?
A. The extrapyramidal tracts are predominantly involved in control of limb muscles.
B. The extrapyramidal tracts synapse onto spinal motor neurons.
C. The corticospinal tract originates mainly in the basal ganglia.
D. The corticospinal tract carries afferent information.
E. The corticospinal tract crosses the midline. |
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Definition
Answer: E
Most fibres cross in the medulla, and so give rise to motor cortex controlling the contralateral side of the body. |
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Term
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?
A. basal ganglia
B. primary motor cortex
C. pre-motor area
D. cerebellum
E. supplementary motor area |
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Definition
Answer: B
The primary motor cortex directly innervates spinal motor neurons and spinal cord interneurons that drive the motor neurons. |
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Term
Reflexes:
A. require only an integrator and an effector.
B. must involve a proprioceptive afferent such as a Golgi tendon afferent.
C. can be used to keep a limb in position.
D. must take less than 10ms otherwise they are not involuntary.
E. are not signalled to the cortex. |
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Definition
Answer: C
Reflexes are best at simple tasks. The myotatic reflex helps hold a limb in position. |
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Term
Choose the CORRECT statement about the retina.
A. Rod photoreceptors outnumber cone photoreceptors throughout the retina except at the fovea.
B. Stimulus location is coded by the type of photoreceptor activated.
C. Stimulus colour is coded by the activity of rod photoreceptors.
D. Increased light intensity causes increased transmitter release from photoreceptors.
E. Rod photoreceptor activity is unaffected by a change in the intensity of a coloured stimulus. |
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Definition
Answer: A
Cone density is low except at the fovea. |
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Term
With regard to spinal motor neurons:
A. Alpha motor neurons synapse onto spindle afferent neurons.
B. The activity of an alpha motor neuron can be influenced by descending cortical input.
C. A motor unit is composed of an alpha motor neuron and a single muscle fibre.
D. A motor unit may be composed of more than one alpha motor neuron.
E. A single action potential in a single alpha motor neuron does not cause muscle contraction. |
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Definition
Answer: B
This is correct and necessary otherwise our muscles wouldn’t be much use to us. |
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Term
When a neuron adapts to a stimulus, this means that it:
A. becomes more selective for the properties of that stimulus.
B. changes its morphology to accommodate the stimulus.
C. becomes sensitised to the stimulus.
D. generates action potentials at a lower rate.
E. generates stronger action potentials. |
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Definition
Answer: D
The response rate decreases over time, even though the stimulus is steady. |
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Term
Which ONE of the following statements about the photoreceptors of the retina is CORRECT?
A. Both rods and cones are found in the centre of the visual field.
B. The highest density of photoreceptors in the eye is at the optic disc.
C. In the peripheral retina, rods are more common than cones.
D. There are more cones than rods in the retina.
E. There are three types of rod photoreceptors and one type of cone photoreceptor. |
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Definition
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Term
A person who is unable to see things to the left side of where their gaze is directed has probably suffered damage to:
A. their right visual cortex (occipital lobe).
B. their right optic nerve before the optic chiasm.
C. their left visual thalamus (lateral geniculate nucleus).
D. their left optic nerve after the optic chiasm.
E. their left eye. |
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Definition
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Term
Choose the option that correctly assigns the roles of the outer, middle and inner ear.
A. outer ear: impedance matching, middle ear: sound transduction,inner ear: modify sound based on location of source.
B. outer ear: modify sound based on location of source, middle ear: impedance matching, inner ear: sound transduction.
C. outer ear: sound transduction, middle ear: impedance matching,inner ear: modify sound based on location of source transduction.
D. outer ear: modify sound based on location of source, middle ear: sound transduction, inner ear: impedance matching.
E. outer ear: impedance matching, middle ear: modify sound based on location of source, inner ear: sound transduction. |
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Definition
Answer: B
The pinna (outer ear) alters a sound to help with localising front/back and up/down; the middle ear achieves impedance matching using the piston effect of the different areas of the tympanic membrane and oval window and the lever effect of the ossicles; the inner ear is where transduction of mechanical to electrical energy actually happens. |
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Term
Which ONE of the following statements about the functional organization of the brain is CORRECT?
A. The left cortical hemisphere generally controls the right side of the body.
B. The thalamus is a single nucleus with inputs from sensory and motor areas.
C. The limbic system is a group of brain areas primarily related to motor control.
D. There is a specialised region of cortex for vision at the front of the brain.
E. Sensory systems are usually restricted to one level of the brain e.g. brain stem |
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Definition
Answer: A
Usually control is crossed, so the right side of the body is controlled by our left cortical hemisphere. |
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Term
Which ONE of the following statements is CORRECT with regard to the organisation of the spinal cord and peripheral nervous system?
A. Ventral roots contain mainly afferent fibres.
B. The spinal cord has a core of white matter surrounded by grey matter.
C. Dorsal root ganglia contain the soma of sensory neurons.
D. A dermatome is innervated from multiple levels of spinal nerves.
E. Efferent fibres take information from the periphery to the central nervous system. |
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Definition
Answer: C
Only the dorsal roots have ganglia. The ventral roots take out the motor signals from the motor neurons with their cell bodies in the spinal cord. These sensory neurons are bipolar: they have two axons - one from the receptor and one going to the CNS. |
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Term
With regard to the organisation of somatosensory cortex:
A. The cortical representation of the hand is found near that of the face.
B. The cortical representation of the hip lies between the representations of the foot and knee.
C. The cortical representation of touch for the right hand is found in the right somatosensory cortex.
D. The cortical area allocated to touch for the wrist is larger than that allocated to touch for the thumb.
E. The cortical representation of temperature sense in the right hand is located in the opposite hemisphere to the cortical representation of touch in the right hand. |
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Definition
Answer: A
There is a disjunction in the topographic map here. |
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Term
The blood-brain barrier:
A. is a semi-permeable membrane that encases the brain and cerebro-spinal fluid.
B. is permeable to most small polar molecules.
C. prevents all drugs from reaching the brain.
D. is permeable to both red blood cells and white blood cells.
E. is produced by astrocytes and endothelial cells of the capillary wall. |
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Definition
Answer: E
These two cell types work together to make the barrier. |
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Term
Which ONE of the following statements about the spinal cord is INCORRECT?
A. The ventral horn of the spinal cord contains motor neurons.
B. The spinal nerves are formed from the fusion of the dorsal and ventral root.
C. The spinal nerves have an organization where the sacral nerves tend to innervate the face, and the cervical nerves innervate the legs.
D. The spinal nerves may fuse and join on their way to innervate their target zone.
E. A dermatome refers to the region of skin innervated by a single spinal nerve. |
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Definition
Answer: C
The spinal nerves do exhibit organization, with sacral nerves innervating the lower body, and cervical nerves the upper body and neck. |
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Term
Which ONE of the following statements is CORRECT with regard to the skin pain system?
A. A person with their spinal cord severed at chest level would have paralysed legs but would still feel painful stimuli applied to their feet.
B. Nociceptive afferent fibres are slower to relay a signal to the spinal cord than the afferents for light touch on the fingers.
C. Strong activation of tactile afferents will cause a sensation of pain.
D. Nociceptive afferents synapse directly on alpha motor neurons to mediate the withdrawal reflex.
E. The ipsilateral (same-side) cortical hemisphere processes nociceptive inputs. |
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Definition
Answer: B
Nociceptive fibres are type Aδ (small myelinated) or C (unmyelinated) and are both smaller than the large myelinated fibres Aβ that carry light touch from the fingertip. |
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Term
[image]
A. The stimulus was moved along the finger from tip to base.
B. No movement.
C. The stimulus was moved along the finger from base to tip.
D. The stimulus was touched on the finger three times, first at the base, then at the middle and finally at the tip of the finger.
E. The stimulus was moved across the tip of the finger. |
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Definition
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Term
The pitch of a pure tone:
A. is not one of the properties coded for in auditory cortex.
B. determines where the travelling wave in the basilar membrane has its peak.
C. is determined by the amplitude of the sound wave.
D. would be dramatically affected by a blockage in the middle ear due to infection.
E. is coded by the rate of firing of cochlear afferent fibres. |
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Definition
Answer: B
This is based on the resonance of the basilar fibres. |
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Term
With regard to image formation by the eye:
A. the focal point of the eye lies between the cornea and the lens.
B. the cornea and lens are concave lenses.
C. the cornea has greater optical power than the lens.
D. myopia is a condition in which the image of a distant object is formed behind the retina.
E. the retinal image is an upright image of the object. |
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Definition
Answer: C
The cornea is roughly twice as powerful as the lens. |
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Term
Which ONE of the following statements about optical defects is CORRECT?
A. Myopia is corrected with a convex lens.
B. The prevalence of myopia is higher in the over-40 population.
C. Hyperopia is usually not corrected in adolescent patients.
D. Presbyopia is corrected with a concave lens.
E. Presbyopia is also called short-sightedness. |
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Definition
Answer: C
The accommodative power of the young eye means that there is no need to correct mild hyperopia. |
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Term
Choose the best option from the following table about spindle and Golgi tendon organ afferents.
[image] |
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Definition
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Term
Which ONE of the following statements about cerebrospinal fluid isINCORRECT?
A. It provides an appropriate chemical environment for the brain.
B. It freely exchanges with the brain interstitial fluid.
C. It fills axons and the central canal of the spinal cord.
D. It enables the brain to float inside the skull.
E. It is produced from blood at the choroid plexus. |
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Definition
Answer: C
This is the incorrect statement. Intracellular fluid is found inside axons; CSF is an extracellular fluid. |
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Term
Choose the CORRECT statement. The vestibular system:
A. uses the utricle and saccule to provide information about static head position.
B. uses hair cells to convert an electrical potential to mechanical energy.
C. provides reflex information that does not go to the cortex.
D. uses the semi-circular canals to detect linear acceleration.
E. would not generate any useful signals in a zero-gravity environment. |
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Definition
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Term
Which ONE of the following statements about cerebro-spinal fluid (CSF) is CORRECT?
A. CSF contains the same white blood cell count as blood, but no red blood cells.
B. The volume of CSF in a normal individual is approximately the same as the volume of plasma.
C. CSF is found both inside and outside the meninges.
D. CSF is made at the choroid plexus.
E. CSF has a higher K+ concentration than Na+ concentration. |
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Definition
Answer: D
CSF circulates through the ventricles and eventually drains into the venous circulation, so more needs to be produced all the time. |
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Term
Tactile sensory fibres with large receptive fields:
A. innervate body regions with low receptor densities.
B. have a large area of cortex dedicated to processing their input.
C. permit precise localization of the site of a tactile stimulus.
D. are found in body regions with small two-point discrimination thresholds.
E. do not have topographically-organised projections. |
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Definition
Answer: A
Low receptor densities are associated with low afferent densities and large receptive fields. |
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Term
With regard to the vestibular senses:
A. The semi-circular canals can signal linear acceleration without significant adaptation.
B. The semi-circular canals use small rocks to help detect inertia.
C. The otolith organs can signal the direction of a steady velocity.
D. The otolith organs can signal linear acceleration without significant adaptation.
E. The semi-circular canals can signal the direction of gravitational acceleration. |
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Definition
Answer: D
This makes them well-suited to signal the direction of gravitational attraction. |
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Term
Which ONE of the following statements about the structure of the brain is CORRECT?
A. The layers of cortex run perpendicular to the cortical surface.
B. Connections between cortical areas are made by white matter tracts.
C. The grey matter of spinal cord is organised as a thin sheet of neurons.
D. The corpus callosum is a grey matter structure.
E. The ventricles are formed by axons. |
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Definition
Answer: B
Cortical communication over any distance happens via bundles of axons called white matter tracts. |
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Term
[image]
The stimulus change that best accounts for the response change from A to B is:
A. making the stimulus surface contact the skin for less time.
B. making the stimulus surface contact the skin with less force.
C. increasing the temperature of the stimulus surface that contacts the skin.
D. making the stimulus surface contact the skin over a larger area.
E. moving the stimulus surface more quickly across the skin. |
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Definition
Answer: B
This is plausible, and suggests it is probably a slowly adapting receptor. |
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Term
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”:
A. generate more action potentials during changes in stimulus intensity than during steady stimulation.
B. can encode only the intensity of a stimulus.
C. include the type of receptor used to encode joint angle.
D. only generate action potentials when the stimulus changes location.
E. generate action potentials continuously during a steady stimulus. |
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Definition
Answer: A
The steady stimulus will lead to adaptation, while the varying stimulus will cause ongoing activity in the receptor/afferent. |
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Term
Inhibitory synapses from a GABA-ergic neuron:
A. can prevent the post-synaptic neuron from reaching threshold.
B. depolarise the post-synaptic neuron membrane potential towards 0 mV.
C. are not found on neurons that also receive excitatory input.
D. cause IPSPs that do not interact with EPSPs in the same post-synaptic neuron.
E. play an important role in synaptic transmission at the vertebrate neuromuscular junction. |
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Definition
Answer: A
This is effectively the ‘mission statement’ for an inhibitory synapse. |
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