sensorimotor systems

Question 1

Example of transduction

Answer 1

Pacinian corpuscle: skin receptors that respond to vibration and pressure (sense texture)

Question 2

Transduction steps to action potential

Answer 2

1. stimuli stretch their membrane
2. opens sodium channels
3. graded generator potential
4. possible action potential

Question 3

Parts of body most sensitive to touch

Answer 3

face, bottom of feet, and fingertips

Question 4

Hierarchical Organization

Answer 4

(association cortex) issues general commands and lower levels (motor neurons and muscles) take care of the details

Question 5

Motor output is guided by…

Answer 5

sensory input

Question 6

Posterior Parietal Association Cortex

Answer 6

• Before an effective response can be initiated, the sensorimotor system must know the positions of various parts of the body and of objects in the external world; current thinking is that the posterior parietal cortex performs these functions.
• The posterior parietal cortex receives input from visual, auditory, and somatosensory systems (that is why it is considered to be an association cortex); most of its output goes to secondary motor cortices.

Question 7

Dorsolateral Prefrontal Association Cortex

Answer 7

Projections to this area are from the posterior parietal cortex; this area projects to parts of the secondary motor cortex, the primary cortex the motor neurons firing the earliest (prior to a motor task) are located in the
the dorsolateral prefrontal cortex, indicating that this area may work with the posterior parietal cortex in decisions regarding voluntary response initiation.

Question 8

Sensorimotor Association Cortex

Answer 8

Posterior Parietal & Dorsolateral Prefrontal

Question 9

Secondary Motor Cortex

Answer 9

Mirror Neurons: fire when an individual performs a particular goal-directed hand movement or when he/she observes the same goal-directed movement performed by another individual
- a possible mechanism for social cognition

Question 10

Primary Motor Cortex

Answer 10

Primary motor cortex is in the precentral gyrus of the frontal lobe. It is somatotopically organized; its organization was discovered by Penfield, who stimulated the cortices of
conscious patients during brain surgery.

Question 11

Sensory Homunculus

Answer 11

map along the cerebral cortex of where each part of the body is processed

Question 12

Cerebellum and Basal Ganglia

Answer 12

The cerebellum and basal ganglia are both important subcortical sensorimotor structures, but neither participates directly in the transmission of signals to the spinal cord.
-higher motor activities

Question 13

Cerebellum

Answer 13

• The cerebellum constitutes only 10% of the brain’s mass, but it contains over half the brain’s neurons
• It is thought to correct deviations from intended movements.
  Long-recognized role in motor learning, and more recently appreciated for a role in the fine tuning and learning of nonmotor cognitive responses.
• 3 roles: balance, coordination, motor learning

Question 14

Phasic VS Tonic receptors

Answer 14

phasic: displays adaption
tonic: show little or no adaption

Question 15

Polymodal

Answer 15

neurons process input from different sensory systems

Question 16

Synesthesia

Answer 16

smelling/tasting colors

Question 17

How is pain described

Answer 17

history, location, quality, intensity

Question 18

Pain receptors

Answer 18

(free nerve endings)// can identify sharp and dull pain

Question 19

Gated Control Theory of Pain Perception

Answer 19

1. applying pressure to the aching area reduces pain
2. acupuncture reduces pain

Question 20

3 areas of cerebral cortex

Answer 20

Primary motor cortex: complex movement
Supplementary Motor cortex: active during raped movements
Premotor cortex: preparation of movement

Question 21

Corticospinal tracts

Answer 21

nerve fibers connecting the cerebral cortex to the spinal cord