Chapter 7

Question 1

Discuss the general organization of the nervous system

Answer 1

The nervous system is divided into two major divisions: (1) the central nervous system and (2) the peripheral nervous system. The central nervous system includes the brain and the spinal cord, whereas the peripheral nervous system includes the nerves outside the central nervous system.

PNS is divided into
afferent
- somatic sensory
- visceral sensory
- special sensory

and

efferent division
- somatic motor
- autonomic motor

Question 2

describe the structure and function of a nerve

Answer 2

Nerve cells (i.e., neurons) are divided anatomically into three parts: (1) the cell body, (2) dendrites, and (3) the axon. Axons are generally covered by Schwann cells, with gaps between these cells called nodes of Ranvier.
Neurons are specialized cells that respond to physical or chemical changes in their environment. At rest, neurons are negatively charged in the interior with respect to the electrical charge outside the cell. This difference in electrical charge is called the resting membrane potential.
A neuron “fires” when a stimulus changes the permeability of the membrane, allowing sodium to enter at a high rate, which depolarizes the cell. When the depolarization reaches threshold, an action potential or nerve impulse is initiated. Repolarization occurs immediately following depolarization due to an increase in membrane perme“Nerve cells (i.e., neurons) are divided anatomically into three parts: (1) the cell body, (2) dendrites, and (3) the axon. Axons are generally covered by Schwann cells, with gaps between these cells called nodes of Ranvier.
Neurons are specialized cells that respond to physical or chemical changes in their environment. At rest, neurons are negatively charged in the interior with respect to the electrical charge outside the cell. This difference in electrical charge is called the resting membrane potential.
A neuron “fires” when a stimulus changes the permeability of the membrane, allowing sodium to enter at a high rate, which depolarizes the cell. When the depolarization reaches threshold, an action potential or nerve impulse is initiated. Repolarization occurs immediately following depolarization due to an increase in membrane permeability to potassium and a decrease permeability to sodium

Question 3

draw and label the pathways involved in a withdrawal reflex

Question 4

define depolarization, action potential, depolarization

Question 5

discuss the role that propiocepters play in kinaesthesia

Answer 5

Proprioceptors are position receptors located in joint capsules, ligaments, and muscles. The three most abundant joint and ligament receptors are free nerve endings, Golgi-type receptors, and Pacinian corpuscles. These receptors provide the body with a conscious means of recognizing the orientation of body parts, as well as feedback about the rates of limb movement.
The muscle spindle functions as a length detector in muscle.
Golgi tendon organs continuously monitor the tension developed during muscular contraction. In essence, Golgi tendon organs serve as safety devices that help prevent excessive force during muscle contractions.
Collectively, proprioceptors provide important information to the CNS about body position and speed of limb movement, which is essential for the successful performance of complex sports skills.

Question 5

decibel the role of vestibular apparatus in maintaining equilibrium

Answer 5

the vestibular apparatus is responsible for maintain general equilibrium and is located in the inner ear. Specifically these receptors provide information about linear and angular acceleration

Question 6

discuss the areas of the brain involved in voluntary control of movement

Answer 6

spinal cord is importnat in voluntary reflex

Question 7

describe the structure and function of the autonomic nervous system

Answer 7

The autonomic nervous system is responsible for maintaining the constancy of the body’s internal environment.
Anatomically and functionally, the autonomic nervous system can be divided into two divisions: (1) the sympathetic division and (2) the parasympathetic division.
In general, the sympathetic portion (releasing norepinephrine) tends to excite an organ, whereas the parasympathetic portion (releasing acetylcholine) tends to inhibit the same organ.

Question 8

discuss the impact of regular educe exercise on maintain brain health and reducing the risk of aggregated memory loss

Answer 8

regular exercise improves brain growth factor
- conginition
- neurogenisis
- vascular function

Question 9

action potential

Question 10

afferent fibers

Answer 10

sensory nervous fibers which conduction information towards the CNS

Question 11

autonomic nervous system

Question 12

axon

Question 13

brain stem

Answer 13

responsible for many metabolic functions, cardiorespiratory control, and complex reflexes

Question 14

cell body

Question 15

central nervous system (CNS)

Question 16

cerebellum

Answer 16

plays important role in coordination and monitoring complex movement
- primary role is to air in control of movement in response to feedback from proprioreceptors

Question 17

cerebrum

Answer 17

large dome of the brain that is divided into right and left. outer most layer site the cortex responsible for
1) organization of the complex movement
2) storage of learned experiences
3) reception of sensory information

Question 18

conductivity

Answer 18

refers to the transmission of the impulse along the axon..

Question 19

dendrites

Question 20

efferent fibers

Answer 20

motor nerve fibers which conduct impulses away from the CNS

Question 21

excitatory postsynaptic potentials (EPSPs)

Answer 21

graded depolarizations caused by neurotransmitters binding to receptors on the target membrane

Question 22

Golgi tendon organs (GTOs)

Answer 22

continuously monitor the tension produced by muscle contraction

Question 23

homeostasis

Question 24

inhibitory postsynaptic potential (IPSP)

Answer 24

hyper polarization of membrane - result in neutron having a more negative membrane potential

Question 25

irritability

Answer 25

is the ability of the dendrites and neutron cell body to respond to a stimulus and cover it to a neural impulse

Question 26

kinesthesia

Answer 26

conscious recognition of the position of body part with respect to another as well as recognition of the speed of limb movement

Question 27

motor cortex

Answer 27

part of cerebrum plays significant role in motor control described as final relay point upon which subcortical inputs are focused. after which the movement is sent to the spinal cord

Question 28

motor neuron

Answer 28

somatic neuron that innervates skeletal muscle fibers

Question 29

motor unit

Answer 29

each motor neuron and all the muscle fibers that it innervates

Question 30

muscle spindle

Answer 30

acts as length detector

Question 31

neurons

Question 32

neurotransmitter

Answer 32

chemical messenger that neutrons use to communicate with each other

Question 33

parasympathetic nervous system

Question 34

peripheral nervous system (PNS)

Question 35

proprioceptors

Answer 35

receptors that provide the CNS with information about body position

Question 36

reciprocal inhibition

Question 37

resting membrane potential

Answer 37

neruon is polarized and this electrical charge difference is called resting membrane potential determine by two factors - permeability of the cell membrane to different ions - the difference in ion concentration between intracellular and extracellular fluid

Question 38

Schwann cells

Answer 38

in large nerve fibers like those innervating skeletal muscles the axons are covered with an insulating layer Called Schwann cells

Question 39

size principle

Answer 39

orderly and sequential recruitment of larger motor units ie for increase force production like weight lifting . will occur in order of increasing size, smaller motor units require less action potential to activate compared to larger motor units therefore small motor units will fire first

Question 40

spatial summation

Answer 40

summation of several different presynaptic inputs

Question 41

sympathetic nervous system

Question 42

synapses

Answer 42

contact point between an axon of one nerudon and the dendrites of another neutron

Question 43

temporal summation

Answer 43

summing of several EPSPs from a single presynaptic neuronal over a short time period (adding of input signals that arrive at different times)

Question 44

vestibular apparatus

Answer 44

organ located in the inner ear, responsible for maintain general equilibrium

Question 45

Identify the location and functions of the central nervous system

Question 45

draw a simple chart illustrating the organization of there nervous system

Question 46

define synapse

Question 47

define the membrane potential and action potential

Question 48

discuss an IPSP and EPSP. how do they differ

Answer 48

Neurotransmitters can be excitatory or inhibitory. An excitatory transmitter increases neuronal permeability to sodium and results in excitatory postsynaptic potentials (EPSPs). Inhibitory neurotransmitters cause the neuron to become more negative (hyperpolarized). This hyperpolarization of the membrane is called an inhibitory postsynaptic potential (IPSP).

Question 49

what are proprioreceptors give an example

Answer 49

Proprioceptors are position receptors located in joint capsules, ligaments, and muscles. The three most abundant joint and ligament receptors are free nerve endings, Golgi-type receptors, and Pacinian corpuscles. These receptors provide the body with a conscious means of recognizing the orientation of body parts, as well as feedback about the rates of limb movement.

Question 50

describe the location and function of the vestibular apparatus

Answer 50

Neurotransmitters can be excitatory or inhibitory. An excitatory transmitter increases neuronal permeability to sodium and results in excitatory postsynaptic potentials (EPSPs). Inhibitory neurotransmitters cause the neuron to become more negative (hyperpolarized). This hyperpolarization of the membrane is called an inhibitory postsynaptic potential (IPSP).

Question 51

what is meant by the term spinal tuning

Answer 51

The spinal mechanism by which a voluntary movement is translated into appropriate muscle action is termed spinal tuning.

Question 52

list the possible motor functions played by the brain stem, the motor cortex and the cerebellum

Answer 52

brain stem - metabolic functions, cardiorespiratory control and complex reflexes motor cortex - final relay point upon which subcortical inputs are focused - controls motor motor activity cerebellum - role in coordination and monitoring complex movement

Question 53

describe the divisions and functions of the autonomic nervous system

Answer 53

sympathetic and parasympathetic

Question 54

define the term motor unit and innervation ration. also define the size principle and describe exercise circumstances whereby the size principle may not apply

Answer 54

motor unit is the motor nueron and all the muscle fibers that it innervates. Innervation ratio number of muscle fibers innervated by a single motor neuron size principle: orderly and sequential recruitment of larger motor units it can be applied when lifting something heavy to increase muscle force production

Question 55

briefly desire the positive benefits of exercise on the brain function

Answer 55

increase conginitino neurogenesis and vascular functions

Question 56

how does regular exercise maintain neural health

Question 57

describe the withdrawal reflex

Question 57

outline the functions of both muscle spindles and the Golgi tendon organ

Answer 57

muscle spindles function as length detector Golgi function as tension detector

Question 57

describe the general anatomical design of a muscle spindle and discuss its physiological function

Answer 57

functions as a length detector

Question 58

discuss the function of Golgi tendon organs in monitoring muscle tension

Answer 58

The spinal mechanism by which a voluntary movement is translated into appropriate muscle action is termed spinal tuning.