Ex Phys Ch. 3

Front 1

A sensory receptor located in the muscle that senses how much the muscle is stretched.

Back 1

Muscle Spindle

Front 2

One of the numerous branched endings of an axon.

Back 2

Axon terminal

Front 3

A decrease in the electrical potential across a membrane, such as when the inside of a neutron becomes less negative relative to the outside.

Back 3

Depolarization

Front 4

A fatty sheath that covers the axons of many neurons to speed nerve conduction.

Back 4

Myelin sheath

Front 5

The summing of all individual changes in a neuron's membrane potential.

Back 5

Summation

Front 6

An increase in the electrical potential across a membrane.

Back 6

Hyperpolarization

Front 7

An involuntary motor response to a stimulus.

Back 7

Motor reflex

Front 8

A minimum amount of stimulus needed to elicit a response. Also, the minimum depolarization required to produce an action potential in neurons.

Back 8

Threshold

Front 9

The electrical signal conducted along a neuron, which can be transmitted to another neuronal an end organ, such as a group of muscle fibres.

Back 9

Nerve impulse

Front 10

Individual nerve fibers, composed of a cell body, dendrites, and an axon.

Back 10

Neuron

Front 11

A chemical used for communication between a neuron and another cell.

Back 11

Neurotransmitter

Front 12

Rapid depolarization of the neuron's membrane lasting only about 1 ms.

Back 12

Action potential

Front 13

The junction between two neurons.

Back 13

Synapse

Front 14

Sensory nerves that carry impulses from a variety of sensory nerves to the CNS.

Back 14

Afferent nerves

Front 15

Nerves that primarily release norepinephrine as a neurotransmitter.

Back 15

Adrenergic

Front 16

Nerves that primarily releases acetylcholine as a neurotransmitter.

Back 16

Cholinergic

Front 17

Senses the tension applied by muscle to its tendon, providing information about the strength of a muscle contraction.

Back 17

Golgi Tendon Organ

Front 18

Motor nerves from the brain and spinal cord that transmit impulses to end organs such as a muscle.

Back 18

Efferent nerves

Front 19

Action potentials flow from __________ neuron axon terminals.

Back 19

Presynaptic

Front 20

Neurotransmitter chemicals released from synaptic vesicles flow across the __________ to postsynaptic neuron's receptors.

Back 20

Synaptic Cleft

Front 21

Axon terminals are __________.

Back 21

Presynaptic

Front 22

The neuron receiving the action potential has __________ receptors.

Back 22

Postsynaptic

Front 23

An alpha-motor neuron communicates with a muscle fiber at the __________.

Back 23

Neuromuscular junction

Front 24

Neuromuscular junctions are different from other neuron transmissions because axon terminals protrude into __________.

Back 24

Motor endplate

Front 25

The refractory period of a neuromuscular transmission limits the __________ firing frequency

Back 25

Motor unit

Front 26

Summation refers to the cumulative effect of all __________ as processed by the axon hillock

Back 26

Graded Potentials

Front 27

Composed of the midbrain, the pons, and the medulla oblongata.

Back 27

Midbrain

Front 28

Critical for coordinating movement.

Back 28

Cerebellum

Front 29

Made up of the brain and spinal cord.

Back 29

Central nervous system

Front 30

Major divisions of the brain.

Back 30

The cerebrum, diencephalon, cerebellum, and brain stem.

Front 31

Includes the thalamus and hypothalamus.

Back 31

Diencephalon

Front 32

Carries both sensory and motor fibres between the brain and the periphery.

Back 32

Spinal cord

Front 33

The conscious brain.

Back 33

Cerebral cortex

Front 34

Crucial to control of all rapid and complex muscular activities.

Back 34

Cerebellum

Front 35

Stores learned motor skills that are repetitive in nature.

Back 35

Premotor cortex.

Front 36

Responsible for fine and discrete muscle movements.

Back 36

Primary motor cortex

Front 37

Cluster of nerve cell bodies, deep to cerebral cortex - but not part of it.

Back 37

Basal Ganglia

Front 38

Important for initiation of sustained and repetitive movement.

Back 38

Basal Ganglia

Front 39

Coordinates timing and rapid progression of motor actives and smoothes movement.

Back 39

Cerebellum

Front 40

Contains pyramidal cells that consciously control movement of skeletal muscle.

Back 40

Primary motor cortex

Front 41

Muscles controlling fine movements have _________ muscle fibers per alpha-motor neuron. Muscles with more general functions have _________ fibers per alpha-motor neuron.

a. a small number of/a small number of

b. a small number of/many

c. many/ a small number of

d. many/many

Back 41

b. a small number of/many

Front 42

What statement is true of muscle spindles?

a. They sense tension in muscles; they inhibit the contracting muscles and excite the antagonist muscles.

b. They supply information on the length and rate of change in length.

c. They initiate movements of a sustained and repetitive nature.

d. They stimulate reflexive muscle relaxation.

Back 42

b. They supply information on the length and rate of change in length.

Front 43

T/F: Sensory impulses that terminate in the spinal cord typically result in a conscious movement

Back 43

False

Front 44

What statement is NOT true of the brain stem?

a. All sensory and motor nerves pass through it as they relay information between the brain and the spinal cord.

b. It contains the major autonomic regulatory centers that exert control over the respiratory and cardiovascular systems.

c. It is the site of origin of all the cranial nerves. d. The reticular formation runs the entire length of the brain stem and influences nearly all areas of the central nervous system.

Back 44

c. It is the site of origin of all the cranial nerves.

Front 45

Neurons in the _________ let us consciously control movement of our skeletal muscles.

a. basal ganglia

b. pyramidal cells

c. primary motor cortex

d. premotor cortex

Back 45

c. primary motor cortex

Front 46

T/F: The sum of all changes in the membrane potential must equal or exceed the threshold to cause sufficient depolarization to generate an action potential.

Back 46

True

Front 47

What statement best describes dendrites?

a. They are the neuron’s receivers; they carry the impulses away from the cell body, and most neurons contain many of them.

b. They are the neuron’s receivers; they carry the impulses toward the cell body, and most neurons contain many of them.

c. They are the neuron’s transmitters; they carry the impulses away from the cell body, and most neurons contain only one of them.

d. They are the neuron’s transmitters; they carry the impulses toward the cell body, and most neurons contain only one of them.

Back 47

b. They are the neuron’s receivers; they carry the impulses toward the cell body, and most neurons contain many of them.

Front 48

T/F: The central nervous system transmits information to various parts of the body through the motor, or efferent, division of the peripheral nervous system.

Back 48

True

Front 49

The _________ receive(s) all sensory input entering the brain.

a. pyramidal cells

b. primary motor cortex

c. cerebellum

d. diencephalon

Back 49

d. diencephalon

Front 50

What nervous system prepares your body to face a crisis, regulating the fight-or-flight response?

a. parasympathetic nervous system

b. central nervous system

c. sympathetic nervous system

d. sensory-motor nervous system

Back 50

c. sympathetic nervous system

Front 51

Which statement is NOT true of an action potential?

a. Any time depolarization reaches or exceeds the threshold, an action potential will result.

b. An action potential is a rapid and substantial depolarization of the neuron’s membrane.

c. An action potential always begins as a graded potential.

d. An action potential is usually just a local event, so the depolarization does not spread very far along the neuron.

Back 51

d. An action potential is usually just a local event, so the depolarization does not spread very far

Front 52

The autonomic nervous system regulates all of the following functions EXCEPT

a. heart rate

b. respiration

c. blood distribution

d. motor control

Back 52

d. motor control

Front 53

The velocity of a nerve impulse transmission is primarily determined by

a. myelination and diameter of the neurons

b. absolute refractory and relative refractory

c. number of muscle fibers per alpha-motor neuron

d. sodium concentration

Back 53

a. myelination and diameter of the neurons

Front 54

T/F: A nerve impulse can be transmitted across a synapse in only one direction.

Back 54

True

Front 55

T/F: Depolarization occurs any time the charge difference in a neuron increases, moving from the resting membrane potential to an even more negative number.

Back 55

False