Chapter 13 For Test #4

Front 1

5 General Characteristics of Polysynaptic Reflexes

Back 1

#1 Involve pools of neurons.

#2 Are intersegmental in distribution

#3 Involve reciprocal inhibition

#4 Have reverberating circuits:

-which prolong relexive motor response

#5 several reflexes cooperate to produce controlled response

Front 2

Conscious and subconscious motor commands control skeletal muscles by traveling over 3 integrated motor pathways?

Back 2

-corticospinal pathway

-medial pathway

-lateral pathway

Front 3

corticospinal pathway

Back 3

-sometimes the pyramidal system

-provides voluntary control over skeletal muscles (conscious)

Front 4

3 pairs of descending tracts

Back 4

corticospinal pathway contains:

-corticonullbar tracts

-lateral corticospinal tracts

-anterior corticospinal tracts

Front 5

Corticobulbar Tract

Back 5

-upper motor neuron synapses in brain stem nuclei on lower motor neuron

-provide conscious control over skeletal muscles that move the eye, jaw, face, neck, pharynx

Front 6

Medulla Pyramids

Back 6

ventral surface of medulla oblongata as a pair of thick bands

Front 7

lateral corticospinal tract decussates in the?

Back 7

medullary pyramids

Front 8

Anterior corticospinal tract decussates?

Back 8

to the opposite side of the spinal cord at the level it synapses on the lower motor neuron

Front 9

location of the upper motor neuron cell bodies

Back 9

CNS processing center

Front 10

Location of lower motor neuron cell bodies?

Back 10

A nucleus of the brain stem or spinal cord

Front 11

Upper motor neuron

Back 11

-synapses on the lower motor neuron

-innervates a single motor unit in a skeletal muscle: activity in upper motor neuron may facilitate or inhibit lower motor

Front 12

Lower motor neuron

Back 12

-Triggers a contraction in innervated muscle: only axon of lower motor neuron extends outside the CNS

-Destruction of or damage to lower motor neuron eliminates voluntary and reflex control over innervated motor unit

Front 13

Lateral Pathways

Back 13

help control distal limbs muscles that perform more precise movements

axons of upper motor neuron in red nuclei cross to opposite side of brain and descend into spinal cord in rubospinal tracts

Front 14

Medial Pathways

Back 14

helps control gross movements of trunk and proximal limb muscles

muscle tone, gross movements of neck/trunk

Front 15

Spinocerebellar

Back 15

-Gerebellum receives proprioceptive info about position of skeletal muscles, tendons, and joints

5, 7,11,10

Front 16

Basal Nuclei

Back 16

provide background patterns of movement involved in voluntary motor activities (conscious)

Front 17

4 properties of a reflex

Back 17

#1 require stimulation

#2 are very fast

#3 are involuntary

#4 are sterotyped (or programmed)

Front 18

5 Steps in Neural Relax Arc

Back 18

#1 Arrival of Stimulus activation of receptors

(physical or chemical changes)

#2 Activation of sensory neuron

(action potential carried to CNS by afferent fibers)

#3 INFO processing by postsynaptic interneuron in CNS

(triggered by neurotransmitters

#4 Activation of motor neuron by interneuron (Action Potential)

#5 Responses of peripheral effector (triggered by neurotransmitters)

Front 19

Innate Reflexes

Back 19

-Basic neural reflexes (grasping, rooting, audio/visual response, withdrawal,etc)

formed before birth

Front 20

Acquired Reflexes

Back 20

-rapid, automatic

(driving, playing, a musical instrument, etc.)

-learned motor patterns

Front 21

Monosynaptic Reflex

Back 21

sensory neuron synapses directly onto motor neuron

have least delay

completed in 20-40 msec

Front 22

Polysynaptic Reflex

Back 22

3 synapse to 2 interneuron

-at least 1 interneuron between sensory neuron * motor neuron

-interneuron control more than 1 muscle group

-produce either ESP's or IPSP's

Front 23

Intersegmental reflex arcs

Back 23

many segments interact produce highly variable motor response

Front 24

Monosynaptic Stretch Reflex

Back 24

-automatically monitors skeletal muscle length and tone

-Patellar (knee jerk) reflex

(input is stretch of spindles)

Front 25

The Tendon Reflex Arc

Back 25

-prevents skeletal muscles from:

-developing too much tension

-tearing or breaking tendons

-promotes muscle relaxation and lengthening

-sensory receptor located in tendons

Front 26

Reciprocal Inhibition

Back 26

For flexor reflex to work:

-the stretch reflex of antagonistic (extensor) muscle ... must be inhibited

(reciprocal inhibition) by interneurons in spinal cord

Front 27

Ipsilateral Reflex Arcs:

Back 27

-occurs on same side of body as stimulus

-stretch, tendon, and withdrawal reflexes

Front 28

Contralateral Reflex Arc

Back 28

Crossed Extensor Reflex

-Occurs on opposite stimulus

-coordinated w/ flexor reflex:

causes leg to pull up, straightens other leg, to receive body weight, maintained by neverberating circuits

Front 29

Cerebellum

Back 29

AffMonitors:

-proprioceptive (position) sensations

-visual info from eyes

-vestibular (balance) sensation from inner ear as movements are under way

Front 30

Afferent Division of the Nervous System

Back 30

-receptors

-sensory neurons

-sensory pathways

Front 31

Action potentials and stimuli

Back 31

stronger stimuli do not produce stronger action potentials

strong stimulus will cause a neuron to fire impulses more rapidly or fire a longer burst of impulses

Front 32

Preception

Back 32

conscious awareness of a sensation