MCQ's: Nervous System Physiology Flashcards
Concerning the enteric nervous system:
A. It contains pre-ganglionic cholinergic fibres
B. Vagal fibres are post-ganglionic
C. It contains post-ganglionic sympathetic fibres
D. Many sympathetic fibres end on cholinergic neurones
E. Many sympathetic fibres end directly on intestinal smooth muscle
A. True. Generally, the parasympathetic supply to the GIT is via pre-ganglionic vagal fibres.
B. False.
C. True. The sympathetic supply is post-ganglionic, but may end on cholinergic neurones or on smooth muscle fibres directly.
D. True.
E. True.
Concerning nerve conduction:
Select true or false for each of the following statements.
A. A-delta fibres are the slowest as they are unmyelinated.
B. A-beta fibres exhibit saltatory conduction
C. C fibres are myelinated
D. A-alpha fibres conduct at 30-70 m/s
E. A-delta fibres provide sensory innervation to muscle spindles.
A. False. A and B fibres are myelinated and therefore have fast conduction velocities due to saltatory conduction.
B. True.
C. False.
D. False. A-alpha fibres conduct at 70-120 m/s
E. False. But A-gamma fibres provide motor supply to muscle spindles.
Hemisection of the spinal cord causes:
Select true or false for each of the following statements.
A. Ipsilateral paralysis
B. Ipsilateral loss of proprioception
C. Contralateral loss of pain sensation
D. Ipsilateral loss of vibration sense
E. Contralateral loss of temperature sensation
A. True. B. True. C. True. D. True. E. True.
Brown-Sequard syndrome (hemisection of the spinal cord) causes ipsilateral paralysis and loss of proprioception, touch and vibration sensation, with contralateral loss of pain and temperature sensation.
Concerning synaptic transmission:
Select true or false for each of the following statements.
A. The synaptic cleft is 100 nm wide B. Temporal summation may occur C. Synaptic delay is normally 0.1 ms D. IPSPs are depolarising E. EPSPs are depolarising
A. False. The synaptic cleft is 30-50 nm wide.
B. True. Summation of excitatory postsynaptic potentials may be both spatial and temporal.
C. False. Synaptic delay is normally 0.5 ms.
D. False. IPSPs are hyperpolarising. GABA + glycine - Make post synaptic membrane potential more negative. Decrease excitibility.
E. True. Ie. Acetylcholine, Glutamate, Aspartate- They bring post synaptic neurone closer to threshold potential with Na influx. Increase excitability.
Concerning pain pathways:
Select true or false for each of the following statements.
A. A-delta have cell bodies within the vental root ganglion of the spinal cord
B. A-delta fibres synapse with cells of the substantia gelatinosa of the spinal cord
C. C fibres synapse with cells in laminae IV and V in the dorsal horn
D. Most ascending neurones are in the anterolateral columns
E. The substantia gelatinosa projects directly to higher levels
A. False. A-delta have cell bodies within the dorsal root ganglia.
B. False. A-delta fibres synapse with cells in laminae I and V of the dorsal horn.
C. False. C fibres synapse with cells in laminae II and III in the dorsal horn.
D. True. Most second order neurones cross within a few segments and ascend in the anterolateral columns (spinothalamic tract).
E. False. The SG does not project directly to higher levels but contains multiple interneurones involved in pain modification.
Concerning sensory receptors:
Select true or false for each of the following statements.
A. Meissners corpuscles are associated with nociception
B. Ruffini corpuscles are associated with proprioception
C. Pacinian corpuscles are associated with vibration
D. Ruffini corpuscles are associated with nociception
E. Pacinian corpuscles are associated with proprioception
A. False. Meissners corpuscles are associated with touch.
B. True.
C. True. Pacinian corpuscles are associated with proprioception and vibration.
D. False. Free nerve endings are associated with nociception
E. True. Pacinian corpuscles are associated with proprioception and vibration.
Therefore: Meissners - touch Pacinian - proprioception + vibration Ruffni - proprioception Free nerve endings - pain
Concerning the knee jerk reflex:
Select true or false for each of the following statements.:
A. It is monosynaptic
B. The synaptic transmitter is glutamate
C. The sensory organ is the muscle spindle
D. It involves spinal roots L2,3,4
E. Glycine inhibition occurs in fibres to antagonistic muscles.
True. True. True. True. True.
The sensory organ is the muscle spindle, which when stretched sends signals to the CNS where a single synapse occurs with the motor supply to the muscle. In addition the Ia fibre from the muscle spindle synapses with an inhibitory interneurone (golgi bottle neurone) which releases inhibitory glycine at the motor neurone to the antagonistic muscle - known as reciprocal innervation.
Concerning the visual pathway:
Select true or false for each of the following statements.
A. Optic tract lesions will cause a bitemporal hemianopia
B. Optic chiasm lesions will cause a bitemporal hemianopia
C. Occipital lesions may spare the macula
D. Optic nerve lesions will cause bilateral loss of vision
E. Field defects start as scotomas.
A. False. Optic tract lesions cause homonymous hemianopia since the optic tracts carry fibres that supply the same field (ie left or right) from both eyes.
B. True. As at the Optic chiasm, temporal fibres cross the midline.
C. True. As the macula fibres are separated from the rest of the cortex subserving vision.
D. False. They will cause unilateral loss of vision.
E. True. These are small areas of visual loss.
Concerning the cranial nerves:
Select true or false for each of the following statements.
A. VII provides taste sensation to the posterior third of the tongue
B. V provides motor fibres to the jaw and tongue
C. IV innervates the inferior oblique muscle
D. III performs most eye movements
E. XII provides motor innervation to palatoglossus
A. False. Taste sensation to the posterior third of the tongue is provided by the glossopharyngeal (IX), the rest being supplied by the chorda tympani accompanying the facial nerve (VII).
B. False. The trigeminal nerve (V) supplies the muscles of mastication and sensation to the forehead and face in the distribution ophthalmic, maxillary and mandibular branches. This includes sensation from the cornea.
C. False. IV innervates the superior oblique muscle.
D. True. With IV and VI supplying superior oblique (to look down and inward) and lateral rectus (abduction) respectively.
E. False. XII innervates all tongue muscles except palatoglossus, which is innervated by X.
In the EEG, delta waves occur:
Select true or false for each of the following statements.
A. With increased cortical activity B. Normally during sleep C. Prominently over the frontal area D. Upon closing the eyes E. Normally in children
Delta waves are abnormal 4Hz waves, though they can be normal in children and during sleep.
Alpha waves are prominent on closing the eyes or with increased cortical activity whilst
beta waves prominent over the frontal area.
