Biopsych Final

Front 1

Principles of sensorimotor function

Back 1

- Hierarchic organization: commands cascade from the cortex to the muscles; allows higher levels to perform more efficient functions

- Motor input is guided by sensory input

- Learning changes the nature and locus of sensorimotor control; "unconscious competence"

Front 2

Hierarchy of sensorimotor system

Back 2

Association cortex
Secondary motor cortex
Primary motor cortex
Brain stem motor nuclei
Spinal motor circuits

Muscles of the spinal motor circuits provide feedback to higher levels, allowing for feedback to the association cortex

Front 3

Posterior parietal association cortex and movement

Back 3

- Receives input from the visual, auditory, and somatosensory systems
- Output goes to the motor cortex

Front 4

Apraxia

Back 4

- Disorder of voluntary movement not attributable to a simple motor, comprehension, or motivation deficit
- Not able to perform movements out of context
- Often caused by unilateral damage to the left posterior parietal lobe

Front 5

Contralateral neglect

Back 5

- Pt unable to respond to stimuli on the side of the body opposite to the side of a brain lesion

Front 6

Dorsolateral prefrontal cortex and movement

Back 6

- Receives projections from the posterior parietal cortex
- Sends projections to areas of secondary and primary motor cortices
- Evaluate and determine voluntary response to external stimuli

Front 7

Secondary motor cortex

Back 7

- Receives input from association cortex
- Areas, not centrally located in any one area of the brain
- Dorsolateral prefrontal cortex determines response to stimuli; secondary MC performs actions

Front 8

Mirror neurons

Back 8

- Fire when an individual performs a particular goal-directed hand movement, OR when s/he notices someone else doing the same movement
- e.g. picking up a toy

Front 9

Motor homunculus

Back 9

- Somatotopic layout of the human PMC
- Most input in face, hands, tongue

Front 10

Primary motor cortex

Back 10

- Precentral gyrus of frontla lobe
- Major locus of convergence in sensorimotor input
- Major point of departure of sensorimotor signals from cerebral cortex

Front 11

Stereognosis

Back 11

- Process of identifying objects by touch

Front 12

Cerebellum

Back 12

- Constitutes 10% of the brain's total mass but contains 50% of its total neurons
- Receives input from primary and secondary MC, information about motor signals from brain stem motor nuclei, and feedback from motor responses

Front 13

Basal ganglia

Back 13

- Part of neural loops that receive cortical input from various cortical areas
- Transmit it back via thalamus to motor cortex

Front 14

Descending motor tracts- direct

Back 14

Dorsolateral corticospinal tract and ventromedial corticospinal tract

- Dorsolateral CST: contains Betz cells, pyramidal neurons of the PMC

Front 15

Descending motor tracts- indirect

Back 15

Dorsolateral corticurubrospinal tract and ventromedial cortico-brainstem-spinal tract

- Corticorubral: projections to the distal muscles of arms and legs

Front 16

Effects of lesions of the primary pyramidal motor tracts

Back 16

Monkeys (Lawrence and Kuypers)

- Could stand, walk, and climb normally after dorsolateral corticospinal tracts transected
- Ability to use limbs for other activities was disrupted (e.g. reaching)
- When corticorubral tracts transected, arm function particularly disrupted

Front 17

Motor unit

Back 17

Smallest unit of motor activity

- One single motor neuron and its individual skeletal muscle fibers

Front 18

Motor pool

Back 18

All the major neurons that innervate the fibers of a single muscle

Front 19

Muscle types

Back 19

Flexors and extensors