Cada pregunta de este test está cronometrada.
regarding reflexes :
a monosynaptic reflex arc involves one or more interneurons
the knee jerk reflex is an example of a stretch reflex
interneurons are the final common path for all reflexes
withdrawal reflexes are lost following cervical section of spinal cord
none of the above
motor impulses are transmitted by :
dorsal root of spinal nerves
dorsal root ganglia of spinal nerves
ventral roots of spinal nerves
none of above
all of the above
which of the following is the type of neuron whose axons forms synaptic junctions with sk. muscle cells "intrafusal fibers" within the muscle spindles ?
alpha motor neurons
pyramidal neurons
gamma motor neurons
granule cells
purkinje cells
which of the following types of neurons is the efferent of nuclear bag intrafusal fibers that signal a change in muscle length ?
static gamma motor neurons
dynamic gamma motor neurons
corticospinal neuron
renshaw cell
which of the following receive direct synaptic input from Golgi tendon organs ?
type Ia inhibitory interneurons
type Ib inhibitory interneurons
type II excitatory interneurons
concerning motor cortex :
the motor areas of the cortex are situated in the postcentral gyrus
following a cerebral haemorrhage affecting the precentral gyrusof the right hemisphere , the patient feels no sensations on left side of the body
the corticospinal tract provides the only connection between the motor cortical areas and the spinal cord
motor areas of the cortex receive somatosensory input via the thalamus
which statement concerning the premotor cortex is correct ?
the premotor cortex is located just posterior to the primary cortex
the lateral to medial sequenc in the somatotopic organization of premotor cortex is the reserve of that seen in the primary motor cortex
stimulation of a small discrete group of neurons in the premotor cortex produces contraction of an individual muscle
stimulation of the premotor cortex does not lead to any muscle activation
the premotor cortex sets the specefic posture required for the limb to produce the desired movement
a stroke involving the middle cerebral artery on the left side is likely to cause which of the following symptoms ?
paralysis of left side of face and left upper extremity
paralysis of left lower extremity
complete loss of vision in both eyes
loss of ability to comprehend speech
loss of vision in left eye
the withdrawal reflex is initiated by stimulation delivered to which of the following receptors?
muscle spindle
joint capsule receptor
cutaneous free nerve ending
golgi tendon organ
pacinian corpuscle
paralysis can result from physical damage to the spinal cord Examples of extensive damage to the spinal cord are :
quadriplegia
paraplegia
planter reflex
A & B only
None of the above
function of cerbellar neurons is,
basket cells evoke excitatory response in purkinje cells
granule cells evoke excitatory response in purkinje cells
golgi cells evoke excitatory response in basket cells
purkinje cells evoke excitatory responses in cerebellar nuclear cells
stellate cells evoke excitatory responses in basket cells
regarding to basal ganglia in motor control :
disorder of the basal ganglia produces a marked loss of both sensation and motor control
parkinsonism is caused by neuronal degeneration within the substantia nigra
the globus pallidus projects directly to the cerebral cortex
site of intiation of fine movement
which of the following terms describes the cerebellar deficit in which there is failure to perform rapid alternating movement:
past pointing
intention tremor
dysarthia
cerebellar nystagmus
dysdiadokokinesia
concerning muscle spindle :
primary afferents arise from nuclear chain fibers only
secondery endings arise from both nuclear bag and nuclear chain
primary afferent belongs to type Ib fibers
primary afferent has the highest conduction velocity in the body
activation of gamma motor neuron :
causes relaxation of extrafusal muscle fibers
causes the contraction of intrafusal muscle fibers
makes the muscle spindle more sensitive to stretch
relax the muscle spindle
a , b & c
regarding upper motor neuron :
it originates from the anterior horn
its chronic lesion causes falccid paralysis
fibrellation is common with its lesion
its lesion is associated with clasp-knife pattern of hypertonia
in generation of motor act :
area 4 responsible for planning
area 6 and basal ganglia help in planning
spino-cerebellum helps in planning
lateral cerebellum adjust the ongoing movement
generation of idea occurs in the occibital lobe
in basal ganglia :
activity in the direct pathway results in increased thalamo-cortical activity
dopamine activate the indirect pathway
globus pallidus externa is a part of the direct pathway
acetyl-choline activates the direct pathway
parkinsonism associated with increased activity in the direct pathway
ataxia is defined as :
inability to perform rapidly alternating movements
error in the range of movement
lack lack of continuity in the execution of movements
error in the rate , force and direction of movement
weakness
walking is controlled by groups of neurons of the spinal cord called :
nuclea and ganglia
the limbic system
central pattern generators
dorsal and ventral horns
corticospinal tract
