Chapter 7 - Nervous System

Front 1

CNS

Back 1

Body's means of perceiving and responding to events in the internal and external environments

Front 2

Nervous system has two main parts

Back 2

PNS

CNS

Front 3

CNS

Back 3

portion of the nervous system contained in the skull and spinal cord

Front 4

division responsible for transmission of neuron impulses from receptors to the CNS

→afferent fibers: nerve fibers conducting info to the CNS

Back 4

Sensory

Front 5

2 Divisions of the PNS

Back 5

sensory and motor

Front 6

division of the PNS has two divisions: somatic and autonomic

Back 6

Motor

nerve fibers conducting impulses away from the CNS → efferent fibers

Front 7

neurons composed of three regions:

Back 7

cell body→ center of of operation

Dendrites→ receptive area conducting impulses toward the cell body

axon→ carries impulses away room the cell body

Front 8

Synapses

Back 8

contact points between an axon of one neuron and the dendrite of another neuron

Front 9

Schwann cells

Back 9

insulated layers of cells that covers the axons

the larger the diameter of the axon the greater the speed of neural transmission

Front 10

multiple sclerosis

Back 10

damage of myelin along myelinated nerve fibers

Front 11

the ability of the dendrites and neuron cell body to respond to a stimulus and convert it to a neural impulse

Back 11

irritability

Front 12

Conductivity

Back 12

transmission of the impulse along the axon

Front 13

resting membrane potential

Back 13

the electrical charge difference

Magnitude of the resting membrane potential: -5 to -100 mv

Front 14

Magnitude of the RMP is determined by:

Back 14

the permeability of the cell Membrane to different ions

the difference in ion concentrations between inside and outside fluids

Front 15

Sodium enters the cell as potassium leaves . true or false

Back 15

yes they go from areas Of high concentration to areas of low concentration

Front 16

Sodium potassium pump

Back 16

maintains the inside and outside ion concentration needed to Maintain the Membrane potential

Front 17

action potential

Back 17

when depolarization reaches "threshold" More Sodium gates open

Front 18

all-or- none law

Back 18

neural impulse is just as strong after traveling the length of the axon as it was at the initial point of stimulation

Front 19

neurotransmitter

Back 19

a chemical Messenger that neurons use to communicate with each other

Front 20

EPSPs

Back 20

excitatory postsynaptic potentials

graded depolarizations that occur after neurotransmitters bind to receptors on the membrane

Front 21

EPSPs can bring the postsynaptic neuron to threshold by

Back 21

temporal summation

spatial summation

Front 22

temporal summation

Back 22

summing of Several EPSPs from a single presynaptic neuron over a short period

Front 23

Spatial summation

Back 23

the sum of EPSPs from different pre synaptic inputs

Front 24

IPSP

Back 24

hyperpolarization of the membrane

neuron develops a more negative resting membrane potential and pushes it further from threshold

Front 25

proprioceptors

Back 25

receptors that provide the CNS with information about body position

- muscle spindles

- golgi tendon organs

- joint receptors

Front 26

three types of joint proprioceptors

Back 26

- free nerve endings→ stimulated strongly at the beginning of movement and later adapt

- golgi type receptors→ Same

- Pacinian Corpuscles→ help detect the rate of joint rotation

concious means of recognition of the Orientation of body parts

parts

Front 27

golgi- type receptors

Back 27

found in ligaments around joints

Front 28

pacinian Corpuscles

Back 28

found in the tissues around joints and adapt rapidly following the iinitiation of movement

helps detect the rate of joint rotation

Front 29

muscle proprietors

Back 29

Sensory receptors are Sensitive to mechanical changes in the muscle

send information to higher brain Centers about movement patterns

also sends afferent neural information to both the cardiovascular and respiratory controlenters

Front 30

muscle spindle

Back 30

Functions as a length detector

found in large numbers in most locomotor muscles

muscle spindles contain two types of sensory nerve endings.

primary nerve endings respond to rapid changes

secondary ending- provides the CNS with continuous information concerning static muscle length

Front 31

The function of the muscle spindle

Back 31

assist in the regulation Of movement and to maintain posture

accomplished by the muscle's spindle ability to detect and cause CNS to respond to changes in the length of skeletal muscle fibers

Front 32

golgi tendon Organs

Back 32

moniter the tension produced by muscle contraction

"Safety, devices " that help prevent excessive Force during muscle contraction

Front 33

inhibitory influences of the GTO on force production could be gradually reduced in response to strength training

Back 33

- golgi tendon Organs s role in the performance of strength activities

Front 34

physiological role of muscle chemoreceptors

Back 34

provide the CNS with Information about the metabolic rate of muscular activity

Front 35

somatic

Back 35

refers to the outer regions of the body < non visceral regions>

carries neural messages from the spinal cord to skeletal muscle fibers

Front 36

motor neuron

Back 36

Somatic neuron that innervates skeletal muscle fibers

Front 37

Size principle

Back 37

orderly and sequential recruitment of larger motor units

Front 38

one way the CNS can increase the force of muscle contraction

Back 38

increasing the number of motor units that are recruited~ the activation of more and more motor neurons

Front 39

Vestibular apparatus

Back 39

responsible for maintaing

general equilibrium

receptors provide info about both linear and angular acceleration of the head

Front 40

motor control functions of the Brain

The Brain is divided into three major parts

Back 40

Cerebrum

cerebellum

Brain stem

Front 41

Cerebrum

Back 41

large dome of the brain

has two hemispheres left and right

outer layer is called the cerebral cortex

Front 42

cerebral cortex

Major important behavior functions:

Back 42

1. the organization of complex Movement

2. the Storage of learned experiences

3. the reception of sensory information

information

information

Front 43

motor cortex

Back 43

most concerned with voluntary movement

Front 44

cerebellum

Back 44

coordinates and monitors complex movement

damage causes: poor movement control and muscular tremor

Front 45

major structures of the brain stem

Back 45

Medulla

Pons

Midbrain

Front 46

Series of complex neurons Scattered throughout the brain stem

Back 46

reticular formation

Front 47

receives and integrates information from all regions of the CNS and works with higher brain centers in controlling muscular activity

Back 47

reticular formation

Front 48

One of the most important roles of the brain Stem

Back 48

Maintaing postural tone

Front 49

the Spinal cord contributes to the control Of movement by:

Back 49

preparing Spinal centers to perform the desired Movement

the withdrawl reflex

Front 50

nerve pathway from the receptor to the CNS and from the CNS along a motor pathway back to the effecter organ

Back 50

reflex arc

Front 51

Describe pathways for the reflex arc

Back 51

P

Front 52

Spinal cord Contributions to the control of Move ment

Back 52

through preparing Spinal centers

Front 53

spinal tuning

Back 53

additional refinement of movement occurs by a complex interaction of spinal cord neurons and higher centers

Front 54

withdral reflex

Back 54

purpose is to provide a rapid means Of removing a limb from a source of pain

Front 55

pathways for this withdrawl reflex :

Back 55

1. a sensory nerve sends a nerve impulse to the spinal column

2. Interneurons within the Spinal cord are excited and in turn Stimulate Motor neurons

3. the excited interneurons cause depolarization of specific motor neurons which control the flexor muscles necessary to withdraw the limb from the point of injury

Front 56

reciprocal inhibition

Back 56

the antagonistic muscle group inhibited by IPSP.s

Front 57

muscle Spindles effect on exercise

Back 57

assistin the regulation of Movement and to Maintain posture