anatomy exam part 4 Flashcards
Describe the roles of premotor cortex and primary cortex in movement
The premotor cortex appears to be involved in the selection of appropriate motor plans for voluntary movements, whereas the primary motor cortex is involved in the execution of these voluntary movements. Premotor cortexneurons signal the preparation for movement.
Describe the function of upper motor neuron, lower motor neuron, alpha and gamma motor neurons
Efferent motor commands from the cerebral cortex are contralateral or “crossed,” meaning that the left cortex controls the muscles on the right side of the body (and vice versa), whereas the Brainstem influences ipsilateral (same side) motor activity.
Describe the function of upper motor neuron, lower motor neuron, alpha and gamma motor neurons
Lower motor neuron: in ventral horn of spinal cord
Lower Motor Neurons
• SAME DAVE
SAME, sensory afferent, motor efferent
DAVE, dorsal afferent, ventral efferent
- Describe the function of muscle spindle and Golgi
Receptors that allow us to sense our position and posture are called proprioceptors.
- Slow adaptation.
- Weight discrimination.
- Three types: muscle spindles, tendon organs and joint kinesthetic receptors.
Describe the function of muscle spindle and Golgi tendons
tendon organs
- tendon organs – proprioceptors in a tendon near its junction with a muscle
* Golgi tendon organ - 1mm long, nerve fibers entwined in collagen fibers of the tendon - tendon reflex – in response to excessive tension on the tendon
- inhibits muscle from contracting strongly
- moderates muscle contraction before it tears a tendon or pulls it loose from the muscle or bone
Describe the function of upper motor neuron, lower motor neuron, alpha and gamma motor neurons
Upper motor neurons → lower motor neurons → skeletal muscles.
Neural circuits involving basal ganglia and cerebellum regulate activity of the upper motor neurons
- Describe corticospinal and corticobulbar pathways
- Direct motor pathway- originates in the cerebral cortex.
- Corticospinal pathway: to the limbs and trunk.
- Corticobulbar pathway: to the head.
- Indirect motor pathway- originates in the brain stem.
Describe three peduncles and their functions in cerebellum; Describe the function of cerebellum in movement control
superior peduncles – connected to the midbrain carries cerebellar output
middle peduncles – connected to the pons
most input from the rest of the brain enters by way of middle peduncle
inferior peduncles – connected to medulla oblongata
most spinal input enters the cerebellum through inferior peduncle
consist of thick bundles of nerve fibers that carry signals to and from the cerebellum
4
SEMIA:
Superior peduncle
Efferent (output)
Middle and Inferior peduncles
Afferent (input)
When you decide to swing a bat, the decision to make this movement originates in
A. prefrontalcortex.
B. the basal ganglia.
C. the cerebellum.
D. primary motor cortex.
In producing movement, the last cortical area to be activated is the
premotor area.
association cortex.
supplementary motor cortex.
primary motor cortex.
premotor area.
association cortex.
supplementary motor cortex.
primary motor cortex.
The actual execution of a movement is triggered by activity in the
primarymotorcortex.
supplementary motor cortex.
premotor cortex.
prefrontal cortex.
Which brain areas contribute to the smoothness of movement?
A. cerebellum and premotor cortex
B. supplementary motor cortex and basal ganglia
C. prefrontal cortex and premotor cortex
D. cerebellum and basal ganglia
A. cerebellum and premotor cortex
B. supplementary motor cortex and basal ganglia
C. prefrontal cortex and premotor cortex
D. cerebellum and basal ganglia
The spinal motor neurons directly responsible for contracting muscles are known as
A. alphamotorneurons.
B.beta motor neurons.
C.motor units.
D. fast-twitch motor neurons.
A. alphamotorneurons.
B.beta motor neurons.
C.motor units.
D. fast-twitch motor neurons.
The “normal” contractile fibers of the muscle are also called the
A. extrafusalfibers.
B.intrafusal fibers.
C.muscle spindle fibers
D. gamma fibers
A. extrafusalfibers.
B.intrafusal fibers.
C.muscle spindle fibers
D. gamma fibers
Alpha motoneurons innervate
A.nuclear chain fibers.
B. nuclear bag fibers.
C. extrafusal fibers.
D. intrafusalfibers.
A. nuclear chain fibers.
B.nuclear bag fibers.
C.extrafusal fibers.
D. intrafusalfibers.
Sensory receptors that are stimulated by the position of the body or its parts are called A. exteroceptors.
B. interoreceptors.
C. nociceptors.
D. proprioceptors.
D. proprioceptors.
Which of these receptors detects an increase in tension in a muscle?
A. Golgitendonorgan
B.Meissner’s corpuscle
C.muscle spindle
D. nociceptor
A. Golgitendonorgan
Which of these receptors detects lengthening or stretching of a muscle?
A. Golgi tendon organ
B. Meissner’s corpuscle
C. muscle spindle
D. nociceptor
C. muscle spindle
When we stretch, we receive information about how far we’re stretching from
efferent fibers.
alpha motor neurons.
muscle spindles.
gammamotorneurons.
muscle spindles.
Without , the intrafusal fibers could not give the brain accurate information about how far the muscle was stretched.
gamma motor neurons
Golgi tendon organs
Ib sensory fibers
extrafusal muscle fibers
gamma motor neurons
Muscle tension (extent of contraction) is detected by
Golgitendonorgans.
muscle spindles.
Lewy bodies.
aandb
a,b,andc
Golgitendonorgans.
The Golgi tendon organs are sensitive to muscle , while the muscles spindle apparatus is sensitive to muscle .
diameter; tension
length; diameter
tension; length (stretch)
tension; length (stretch)
The effector in a reflex is the
control center.
efferent neuron.
efferent neuron.
sensory receptor.
muscle or gland.
muscle or gland.
Most reflex movements are integrated by
the brain.
the spinal cord.
central pattern generators.
proprioceptors.
effectors.
the spinal cord.
Voluntary control of skeletal muscles is provided by the
posterior column.
reticular formation.
spinothalamic tract.
corticospinalpathway.
medullary centers.
corticospinalpathway.
Most fibers of the direct (pyramidal) system belong to the lateral corticospinal pathway and they
crossthemidlineinthemedullaoblongata.
synapse in the pons.
descend in the rubrospinal tract.
begin in the cerebellum.
cross themidline in the medulla oblongata.
Which pathway controls voluntary fine movements of the skeletal muscles of facial expression and of the tongue?
corticobulbar pathway
Tectospinal pathway
Lateral corticospinal pathway
Anterior corticospinal pathway
corticobulbar pathway
The ___ tracts innervate the head muscles
corticospinal
rubrospinal
vestibulospina
corticobulbar
dorsal-column/medial-lemniscal
corticobulbar
Which of these pathways is direct (pyramidal) pathway?
reticulospinal tract
corticobulbar tract
rubrospinal tract
vestibulospinal tract
corticobulbar tract
Which of the following structures is NOT part of the basal ganglia?
caudate nucleus
globus pallidus
thalamus
putamen
thalamus
The main function of the cerebellum is .
consciousness
muscle coordination
homeostasis
muscle coordination
Thecerebellum
initiates movement.
participates in the choice of voluntary movements.
manages complex sequences of movements.
plays a role in the sequencing of complex movements.
plays a role in the sequencing of complex movements.
The motor nerve tracts that link the cerebellum with the brain stem are contained within the
precentral gyrus.
postcentral gyrus.
cerebellar peduncles.
hypothalamus.
cerebral peduncles.
cerebellar peduncles.
Output from the cerebellum extends through the
superiorcerebellarpeduncles
middle cerebellar peduncles
inferior cerebellar peduncles
anterior cerebellar peduncles
superiorcerebellarpeduncles
Most spinal input enters the cerebellum through
superior cerebellar peduncles
middle cerebellar peduncles
inferior cerebellar peduncles
anteriorcerebellarpeduncles
inferior cerebellar peduncles
Purkinje cells are distinctive multipolar neurons found in_
primary motor cortex
basal nuclei
cerebellum
spinalcord
cerebellum
The cerebellum is involved in
the order and timing of complex movements.
the learning of motor skills.
judging the speed of objects.
a and b.
a, b, and c.
a, b, and c.
