anatomy exam part 4

Question 1

Describe the roles of premotor cortex and primary cortex in movement

Answer 1

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.

Question 2

Describe the function of upper motor neuron, lower motor neuron, alpha and gamma motor neurons

Answer 2

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.

Question 3

Describe the function of upper motor neuron, lower motor neuron, alpha and gamma motor neurons

Answer 3

Lower motor neuron: in ventral horn of spinal cord

Lower Motor Neurons

• SAME DAVE
SAME, sensory afferent, motor efferent

DAVE, dorsal afferent, ventral efferent

Question 4

47. Describe the function of muscle spindle and Golgi

Answer 4

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.

Question 5

Describe the function of muscle spindle and Golgi tendons

tendon organs

Answer 5

1. 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
2. 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

Question 6

Describe the function of upper motor neuron, lower motor neuron, alpha and gamma motor neurons

Answer 6

Upper motor neurons → lower motor neurons → skeletal muscles.

Neural circuits involving basal ganglia and cerebellum regulate activity of the upper motor neurons

Question 7

49. Describe corticospinal and corticobulbar pathways

Answer 7

• 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.

Question 8

Describe three peduncles and their functions in cerebellum; Describe the function of cerebellum in movement control

Answer 8

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)

Question 9

When you decide to swing a bat, the decision to make this movement originates in

Answer 9

A. prefrontalcortex.

B. the basal ganglia.

C. the cerebellum.

D. primary motor cortex.

Question 10

In producing movement, the last cortical area to be activated is the

premotor area.

association cortex.

supplementary motor cortex.

primary motor cortex.

Answer 10

premotor area.

association cortex.

supplementary motor cortex.

primary motor cortex.

Question 11

The actual execution of a movement is triggered by activity in the

Answer 11

primarymotorcortex.

supplementary motor cortex.

premotor cortex.

prefrontal cortex.

Question 12

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

Answer 12

A. cerebellum and premotor cortex

B. supplementary motor cortex and basal ganglia

C. prefrontal cortex and premotor cortex

D. cerebellum and basal ganglia

Question 13

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.

Answer 13

A. alphamotorneurons.

B.beta motor neurons.

C.motor units.

D. fast-twitch motor neurons.

Question 14

The “normal” contractile fibers of the muscle are also called the

A. extrafusalfibers.

B.intrafusal fibers.

C.muscle spindle fibers

D. gamma fibers

Answer 14

A. extrafusalfibers.

B.intrafusal fibers.

C.muscle spindle fibers

D. gamma fibers

Question 15

Alpha motoneurons innervate

A.nuclear chain fibers.

B. nuclear bag fibers.

C. extrafusal fibers.

D. intrafusalfibers.

Answer 15

A. nuclear chain fibers.

B.nuclear bag fibers.

C.extrafusal fibers.

D. intrafusalfibers.

Question 16

Sensory receptors that are stimulated by the position of the body or its parts are called A. exteroceptors.
B. interoreceptors.
C. nociceptors.

D. proprioceptors.

Answer 16

D. proprioceptors.

Question 17

Which of these receptors detects an increase in tension in a muscle?

A. Golgitendonorgan

B.Meissner’s corpuscle

C.muscle spindle

D. nociceptor

Answer 17

A. Golgitendonorgan

Question 18

Which of these receptors detects lengthening or stretching of a muscle?

A. Golgi tendon organ

B. Meissner’s corpuscle

C. muscle spindle

D. nociceptor

Answer 18

C. muscle spindle

Question 19

When we stretch, we receive information about how far we’re stretching from

efferent fibers.

alpha motor neurons.

muscle spindles.

gammamotorneurons.

Answer 19

muscle spindles.

Question 20

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

Answer 20

gamma motor neurons

Question 21

Muscle tension (extent of contraction) is detected by

Golgitendonorgans.

muscle spindles.

Lewy bodies.

aandb

a,b,andc

Answer 21

Golgitendonorgans.

Question 22

The Golgi tendon organs are sensitive to muscle , while the muscles spindle apparatus is sensitive to muscle .

diameter; tension

length; diameter

tension; length (stretch)

Answer 22

tension; length (stretch)

Question 23

The effector in a reflex is the

control center.

efferent neuron.

efferent neuron.

sensory receptor.

muscle or gland.

Answer 23

muscle or gland.

Question 24

Most reflex movements are integrated by

the brain.

the spinal cord.

central pattern generators.

proprioceptors.

effectors.

Answer 24

the spinal cord.

Question 25

Voluntary control of skeletal muscles is provided by the posterior column. reticular formation. spinothalamic tract. corticospinalpathway. medullary centers.

Answer 25

corticospinalpathway.

Question 26

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.

Answer 26

cross themidline in the medulla oblongata.

Question 27

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

Answer 27

## Footnote corticobulbar pathway

Question 28

The ___ tracts innervate the head muscles corticospinal rubrospinal vestibulospina corticobulbar dorsal-column/medial-lemniscal

Answer 28

corticobulbar

Question 29

Which of these pathways is direct (pyramidal) pathway? reticulospinal tract corticobulbar tract rubrospinal tract vestibulospinal tract

Answer 29

corticobulbar tract

Question 30

Which of the following structures is NOT part of the basal ganglia? caudate nucleus globus pallidus thalamus putamen

Answer 30

thalamus

Question 31

The main function of the cerebellum is . consciousness muscle coordination homeostasis

Answer 31

muscle coordination

Question 32

Thecerebellum initiates movement. participates in the choice of voluntary movements. manages complex sequences of movements. plays a role in the sequencing of complex movements.

Answer 32

plays a role in the sequencing of complex movements.

Question 33

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.

Answer 33

cerebellar peduncles.

Question 34

Output from the cerebellum extends through the superiorcerebellarpeduncles middle cerebellar peduncles inferior cerebellar peduncles anterior cerebellar peduncles

Answer 34

superiorcerebellarpeduncles

Question 35

Most spinal input enters the cerebellum through superior cerebellar peduncles middle cerebellar peduncles inferior cerebellar peduncles anteriorcerebellarpeduncles

Answer 35

inferior cerebellar peduncles

Question 36

Purkinje cells are distinctive multipolar neurons found in\_ primary motor cortex basal nuclei cerebellum spinalcord

Answer 36

cerebellum

Question 37

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.

Answer 37

a, b, and c.