Week7

Question 1

The cerebellum plays an important role in ____, while the basal ganglia play an important role in ____ .

Answer 1

timing; voluntary movements

Question 1

Early symptoms of Huntington’s disease usually include

Answer 1

Jerky arm movements and body tremors

Question 2

Proprioceptive system

Answer 2

Body awareness; location of your
body in space

Question 3

Movement Hierarchy

Answer 3

Reflexes
Automated movements
Voluntary movements

Question 4

Reflexes

Answer 4

triggered by a sesnory stimulus
little voluntary control, can be modulated
eye blink

Question 5

Automated movements

Answer 5

Postural: combination of reflex and volition used to
maintain an upright position with respect to gravity;
e.g., vestibulospinal reflexes
** Rhythmic**: initiation and termination is voluntary,
but the actual movement is more stereotyped; e.g.,
walking, running, chewing

Question 6

Voluntary movements

Answer 6

• CNS responsible
• improves by practice
• reflex and postural movements compensate for the
  effects of the intended action

Question 7

Muscle Structure

Answer 7

attached at origin and insertion

Question 8

Muscles Fibers and Axons

Answer 8

• Each muscle fiber receives information from only one axon; but a single axon may innervate many muscle fibers
• A neuromuscular junction is a synapse between a motor neuron axon and a muscle fiber

Question 9

Acetylcholine

Answer 9

always excites skeletal muscles to contract (no relax cue)

Question 10

slow twitch

Answer 10

red
aerobic
Nonstrenuous activities

Question 11

Proprioceptors

Answer 11

receptors that detect the position or movement of a part of the body

Question 12

Muscle spindles(Proprioceptors)

Answer 12

Proprioceptors parallel to the muscle that respond to a stretch: cause a contraction of the muscle
* A stretch reflex occurs when muscle proprioceptors detect the stretch and tension of a muscle and send messages to the spinal cord to contract it

Question 13

Golgi tendon organ
(Proprioceptors)

Answer 13

• responds to increases in muscle tension
• Located in the tendons at the opposite ends of the muscle
• Acts as a “brake” against excessively vigorous contraction by sending an impulse to the spinal cord where motor neurons are inhibited

Question 14

The primary motor cortex (M1)

Answer 14

• Muscle control
• intention of a movement
• opposite side of the body(mostly)

Question 15

Posterior parietal cortex;

Answer 15

position of the body
Damage to this area causes difficulty in coordinating visual stimuli with movement
- Important for planning movement

Question 16

Premotor cortex

Answer 16

• preperation for movement
• Receives information about a target
• Integrates information about position and posture of the body;organizes the direction of the movement in space

Question 17

• Supplementary motor cortex

Answer 17

Organizes rapid sequence of movements in a specific order; inhibitory if
necessary
- Active seconds before the movement - Active following an error in movement so you can inhibit the incorrect
movement the next time

Question 18

PFC

Answer 18

Active during a delay before movement
- Stores sensory information relative to a movement
- Necessary for you to consider the probable outcomes
of a movement
not directly connected to the spinal cord

Question 19

Antisaccade task

Answer 19

inhibit a saccade, a voluntary eye movement from one target to another
pfc and basal ganglia before seeing the moving stimulus
matures through adolescensce

Question 20

From the Brain to the Spinal Cord

Answer 20

• Messages from the brain must reach the medulla
  and spinal cord to control the muscles
• Corticospinal tracts are paths from the cerebral
  cortex to the spinal cord

Question 21

Lateral Corticospinal Tract

Answer 21

axons from PMC,red nucleus to the spinal cord
- Controls movement in peripheral
areas (hands and feet)
- Red nucleus: a midbrain area with
output mainly to the arm muscles
* Axons extend from one side of the
brain to the opposite side of the
spinal cord, and control opposite
side of the body

Question 22

Medial Corticospinal Tract

Answer 22

Reticular formation, midbrain tectum, and vestibular nucleus
* Vestibular nucleus is a brain area that receives information from the vestibular system
* The medial tract controls the muscles of the neck, shoulders,
and trunk - Responsible for bilateral movements like walking, turning, bending, standing up, and sitting down

Question 23

The Cerebellum

Answer 23

balance-coordination
damage causes trouble in rapid movements(aim/timing)
clapping,speaking,writing
responds to unexpected sensory stimulus
attention(shifting it)

Question 24

Purkinje Cells

Answer 24

Purkinje cells: flat parallel cells in sequential planes
Parallel fibers excite Purkinje cells
purkinje cells send inhibitory measseges to nuclei of the cerebellum
then sent to midbrain and the thalamus.

Question 25

The Basal Ganglia
(IN-IN)
(direct- excitatory)

Answer 25

• Caudate nucleus-Putamen( receive input from cerebral c. and send to globus pallidus.
• Globus pallidus(connects to thalamus for pmc and pfc
• learning motor skills, organizing sequences of movement, “automatic” behaviors, and new habits
  driving a car, playing the piano, sports

Question 26

Parkinson’s Disease
(Damaged mitochondria)

Answer 26

• muscle tremors, rigidity, slow movements, masked face, posture/gait issues
• difficulty in initiating spontaneous
  movement in the absence of stimuli to guide the
  action

Question 27

Huntington’s Disease
(chromosome 4)

Answer 27

• neurodegenerativea
• dominant genetic mutation
• toxic to thecaudate and putamen
• kaput basal ganglia
• chorea Overstimulation of the motor drive (opposite to PD!)