Quiz 9

Question 1

lower motor neurons responsible for posture and locomotion are found in the ____ and primarily receive input from upper motor neurons in the ____

-medial dorsal horn; brainstem
-lateral ventral horn; cerebral cortex
-medial ventral horn; brainstem
-medial ventral horn; cerebral cortex
-lateral ventral horn; brainstem

Answer 1

medial ventral horn; brainstem

Question 2

in which area of the spinal cord can the axons of upper motor neurons that supply lower motor neurons for skilled movements be found?

-medial ventral horn
-medial white matter
-lateral ventral horn
-lateral white matter

Answer 2

lateral white matter

Question 3

see quiz question 3
anterior highlighted part of brain
more posterior behind that region

Answer 3

anterior: premotor cortex
behind: primary motor cortex

Question 4

which of the following body areas listed has teh greatest area of motor cortex devoted to it?

-wrist
-knee
-neck
-lips

Answer 4

lips

Question 5

what is the name of the neurons that fire when an animal observes and performs a goal-oriented task?

-betz cells
-mirror motor neurons
-reticular formation
-broca’s area

Answer 5

mirror motor neurons

Question 6

a “muscle field”

-includes all of the muscles that are co-activated during any given behavior
-is the force vector produced by stimulating an individual upper motor neuron
-includes all of the upper motor neurons that innervate a particular lower motor neuron
-is the group of muscles whose activity is directly facilitated by a given upper motor neuron
-is the force vector produced by stimulating a small field of cortical premotor neurons

Answer 6

is the group of muscles whose activity is directly facilitated by a given upper motor neuron

Question 7

which statement about directional tuning and population coding by primary motor cortical neurons is true?

-the precision of directional motor movements equals the precision of directional tuning of individual primary motor cortical pyramidal cells
-most primary motor cortical neurons have two or three distinct, preferred directions separated by intervening ranges of non-preferred directions
-the vector summation of population responses of primary motor cortical neurons is important for directional control of motor movements
-primary motor cortical neurons do not code direction

Answer 7

the vector summation of population responses of primary motor cortical neurons is important for directional control of motor movements

Question 8

neurons from the ____ are responsible for regaining balance and posture via projections to the proximal muscles of the limbs

-lateral vestibulospinal tract
-reticular formation
-medial vestibulospinal tract
-red nucleus

Answer 8

lateral vestibulospinal tract

Question 9

which upper motor neuron syndrome symptom is also present in healthy infants?

-spasticity
-babinski sign
-spinal shock
-decerebrate rigidity

Answer 9

babinski sign

Question 10

the “indirect pathway” from cortex to spinal cord does NOT play a role in

-weight shifts, as when a cat lifts one paw.
-post-injury recovery of fine motor functions such as using 2 fingers to pick up food
-feed-forward postural adjustments
-relaying information from cortex to spinal cord via the reticulospinal neurons

Answer 10

post-injury recovery of fine motor functions such as using 2 fingers to pick up food