The Sensorimotor System

Question 1

Receptive field

Answer 1

A region of space in which a stimulus will alter that neurons firing rate

Question 2

Excitatory regions in the receptive field

Answer 2

The area where stimulation increases the neurons firing rate

Question 3

Inhibitory regions in the receptive field

Answer 3

Stimulation decreases or suppresses the neurons firing rate

Question 4

Pacinian corpuscles

Answer 4

Senses vibration and pressure, textures

Question 5

Meissner’s corpuscle

Answer 5

Senses touch and changes in stimuli

Question 6

Merkel’s discs

Answer 6

Senses touch, edges and isolated points. Part of Meissner’s corpuscle

Question 7

Ruffini corpuscles

Answer 7

Senses stretching of the skin

Question 8

Free nerve endings

Answer 8

Sense pain, heat and cold

Question 9

Sensory adaptation

Answer 9

Progressive decrease in a receptors response to a sustained simulation

Question 10

Phasic receptors

Answer 10

Adapt/undergo sensory adaptation

Question 11

Tonic receptors

Answer 11

Do not adapt/undergo sensory adaptation

Question 12

Dorsal column system

Answer 12

Reports touch information to the brain.

Receptors→axons via spinal cord→synapse on neurons in brainstem→go to different regions of the thalamus where they are emphasized or suppressed

Question 13

Primary motor cortex (M1)

Answer 13

Organized like map of the body, change firing rate according to the direction of movement

Question 14

Nonprimary motor cortex

Answer 14

Premotor cortex and supplementary motor area

Question 15

Premotor cortex

Answer 15

Anterior to M1 and activated when motor sequences are guided by external events

Question 16

Supplementary motor area (SMA)

Answer 16

Important for initiation of motor sequences especially preplanned

Question 17

Basal ganglia

Answer 17

Picture

Question 18

Sensory-discriminative dimension of pain experience

Answer 18

What you feel eg. throbbing

Question 19

Motivational-affective dimension of pain experience

Answer 19

What you feel emotionally eg. sickening

Question 20

Cognitive-dimension of pain experience

Answer 20

The overall experience eg. mild

Question 21

A-delta fibers

Answer 21

Contain TRPM3 which is myelinated, fast conducting and transmits sharp, well-localized pain signals

Question 22

C fibers

Answer 22

Contain TRPV1 which are unmyelinated, slower conducting, and transmit dull, diffuse, or burning pain signals

Question 23

Central gray

Answer 23

Electrically activates endorphin-mediated pain control systems blocking the pain signal in the spinal cord

Question 24

TENS

Answer 24

The delivery of electrical pulses through electrodes attached to the skin, which excite nerves that supply the region to which pain
is referred.

Question 25

Pyramidal system (corticospinal)

Answer 25

The motor system that includes neurons within the cerebral cortex and their axons, which form the pyramidal tract. Lesions cause paralysis in controlled muscles.

Question 26

Extrapyramidal system

Answer 26

Includes basal ganglia and some closely related brainstem structures. Axons of this system pass into the spinal cord outside the pyramids of the medulla. Lesions interfere with spinal reflexes and fine-tune motor control

Question 27

Proprioception

Answer 27

The collection of information about body movements and position in space

Question 28

Muscle spindle

Answer 28

Responds to stretch, buried in muscles

Question 29

Golgi tendon organs

Answer 29

Sensitive to tension, detects overloads that may tear muscle

Question 30

Huntingtons disease

Answer 30

Caused by damage to the caudate and putamen. Characterized by excessive movement, clumsiness and twitches of fingers/face.

Question 31

Parkinsons disease

Answer 31

Loss of dopaminergic cells in substantia nigra. Characterized by slowed movement, tremors, and reduced facial expressions.

Question 32

Primary somatosensory cortex (S1)

Answer 32

Where sensory inputs from the body surface are mapped. Receives touch information from opposite side of body, Cells are organized in sensory homunculus

Question 33

Central modulation of sensory information

Answer 33

The process in which higher brain centers, such as the cortex and thalamus, suppress some sources of sensory information and amplify others.

Question 34

Neuropathic pain

Answer 34

Pain that persists long after the injury that started it has
healed.

Question 35

Electromyography (EMG)

Answer 35

The electrical recording of muscle activity.

Question 36

Antagonist muscle

Answer 36

A muscle that counteracts the effect of another muscle.

Question 37

Synergist muscle

Answer 37

A muscle that acts together with another muscle.