Human Physiology Chapter 11: The Nervous System Part 1

Front 1

What kind of system is the nervous system?

Back 1

It is a communication system

Front 2

What is the main difference between the nervous system and the endocrine system?

Back 2

The difference is the speed of the responses.

Front 3

How fast are hormone actions?

Back 3

Minutes to hours to days

Front 4

How fast are nerve impulses?

Back 4

1 milliseconds

Front 5

What is a neuron?

Back 5

A neuron is a individual nerve cell

Front 6

What region is the axon? What does it do?

Back 6

It is the region in the middle that generates impulses and conduction.

Front 7

What is a nerve?

Back 7

A nerve is a bundle of neurons (axon) in the peripheral nervous system

Front 8

What is the peripheral nervous system?

Back 8

All neurons outside the brain and spinal cord

Front 9

What is the central nervous system?

Back 9

Brain and spinal cord

Front 10

What are tracts?

Back 10

Bundle of nerves in he brain

Front 11

What does innervate mean?

Back 11

Innervate means provide with a nerve supply

Front 12

What is a synapse?

Back 12

A synapse is the point of closest contact between two neurons

Front 13

Where is a neurotransmitter secreted from?

Back 13

It is secreted from a presynaptic neuron

Front 14

What does the NT do after it's been secreted from the presynaptic neuron?

Back 14

It binds to post-synaptic neurons which may excite or inhibit firing of APs.

Front 15

What do sensory receptors respond to?

Back 15

They respond to internal and external changes

Front 16

What pathway does information carried by the sensory neurons travel on? Where does it go?

Back 16

Afferent pathway. Carried TOWARD the CNS

Front 17

Where do association neurons carry out integration entirely within?

Back 17

Entirely within the CNS!

Front 18

What 3 processes are part of integration?

Back 18

1. Interpretation of sensory input
2. Store and retrieve information, make decisions
3. Initiate motor output

Front 19

What do motor neurons do?

Back 19

Motor neurons signal to effectors to produce a response

Front 20

What are effectors?

Back 20

Muscles and glands

Front 21

Motor neurons send information on what pathway? Where does it go?

Back 21

Efferent pathways. Information travels AWAY from CNS

Front 22

What does SAME stand for?

Back 22

Sensory Afferent Motor Efferent

Front 23

What does the structure of neurons allow neurons to do?

Back 23

Structure of neurons lets them carry out their functions

Front 24

Neurons are what kind of cells?

Back 24

Excitable cells

Front 25

When neurons are stimulated, how do they respond?

Back 25

Neurons respond by firing action potentials

Front 26

What are action potentials?

Back 26

APs are long distance electrical signals

Front 27

What is a multipolar neuron?

Back 27

A multipolar neuron is a neuron with two or more dendrites coming off the neuron cell body

Front 28

What are the most common neurons?

Back 28

Association and motor neurons

Front 29

What are the four parts of a multipolar neuron?

Back 29

Cell body, dendrites, Axon, and Axon terminals

Front 30

What is the biosynthetic center? What does it do?

Back 30

The biosynthetic center is in the cell body that carries out cellular functions such as protein synthesis and NT synthesis

Front 31

Dendrites and the cell body make up what region on a neuron?

Back 31

Receptive region

Front 32

What are dendrites?

Back 32

Dendrites are short cytoplasmic processes

Front 33

What do dendrites do?

Back 33

Dendrites are the "antennae" to receive input from other neurons or sensory receptors

Front 34

What do dendrites and cell bodies produce?

Back 34

Dendrites produce excitatory post-synaptic potentials and inhibitory post-synaptic potentials

Front 35

How many axons are there per cell?

Back 35

One!

Front 36

How long are axons?

Back 36

Axons can be short or long (up to 3 feet).

Front 37

Axons arise from what part of a neuron?

Back 37

Axons arise from the axon hillock

Front 38

What is the axon hillock?

Back 38

It is the trigger zone where action potentials are initiated

Front 39

Where are action potentials initiated?

Back 39

At the axon hillock, or trigger zone.

Front 40

The axon makes up what region on a neuron?

Back 40

Axons make up the conducting region on neurons

Front 41

What are axon terminals?

Back 41

Axon terminals are the secretory region of neurons that secrete NT molecules.

Front 42

What are NTs?

Back 42

NTs are chemicals that may excite or inhibit the post-synaptic neuron

Front 43

What does the NT Acetylcholine (ACh) do?

Back 43

ACh causes skeletal muscles to contract

Front 44

What does the NT Norepinephrine (NE) do?

Back 44

NE causes smooth muscle to contract

Front 45

What cells form myelin in the PNS?

Back 45

Schwann cells

Front 46

What cells form myelin in the CNS?

Back 46

Oligodendrocytes

Front 47

Schwann cells wraps around the axon to form what?

Back 47

To form concentric layers of phospholipids

Front 48

What is the purpose of myelin?

Back 48

Electrical Insulation

Front 49

What are the functions of myelin?

Back 49

Electrically insulates the axon and to increase the speed of nerve impulse transmission

Front 50

How fast do unmyelinated fiber conducts?

Back 50

Unmyelinated fiber conducts APs at 1 meter/sec

Front 51

How fast does myelinated fiber conducts?

Back 51

Myelinated fiber conducts APs at up to 150 meters/sec

Front 52

Neuron signals occur to due to what?

Back 52

Ions entering and leaving

Front 53

What is a graded potential?

Back 53

A graded potential is a short distance electrical signal

Front 54

Where do graded potentials occur?

Back 54

Cell body/Dendrites in the receptive region

Front 55

What is the purpose of GPs?

Back 55

Excite or inhibit action potentials

Front 56

What are action potentials?

Back 56

APs are long distance electrical signal

Front 57

Where do APs originate?

Back 57

Trigger zone on the axon

Front 58

What is the purpose of APs?

Back 58

To set off NT secretion

Front 59

Where do NTs originate?

Back 59

NTs originate in the axon terminals

Front 60

What is the purpose of NTs?

Back 60

NTs excite or inhibit post-synaptic neuron. NTs set off graded potentials

Front 61

What is another name for graded potentials?

Back 61

Post-synaptic potentials

Front 62

What sets off the three signals in a neuron?

Back 62

The opening of gated ion channels

Front 63

What do ions do when gated channels open?

Back 63

Ions diffuse through the channel down their concentration gradients

Front 64

How do ions diffuse?

Back 64

Channel mediated facilitated diffusion

Front 65

GP occur due to the diffusion of what ions?

Back 65

Na+, K+, or Cl-

Front 66

APs occur due to the diffusion of what ions?

Back 66

Due ONLY to Na+ and K+

Front 67

NT secretion occurs due to the diffusion of what ions?

Back 67

Ca+2 (into the cell)

Front 68

Ion diffusion in the receptive region sets off what signal?

Back 68

Graded potential

Front 69

Leak channels are always what?

Back 69

Leak channels are always open!

Front 70

Where are leak channels located?

Back 70

All over the neuron

Front 71

There are more leak channels for what ion?

Back 71

More leak channels for K+

Front 72

What are leak channels responsible for?

Back 72

Leak channels are responsible for the resting membrane potential

Front 73

What are the two main types of gated channels?

Back 73

Chemically-gated channels and voltage-gated channels

Front 74

What is another name for chemically gated channels?

Back 74

Ligand-gated channels

Front 75

What chemical opens chemical-gated channels?

Back 75

NTs!

Front 76

Where are chemically gated channels located?

Back 76

In the plasma membrane of the receptor region in neurons

Front 77

Voltage-gated channels open and close due to what?

Back 77

They open and close due to voltage changes

Front 78

What is voltage?

Back 78

Voltage is the separation of charge across the membrane

Front 79

The inside of a neuron has normally what charge?

Back 79

Negative charge

Front 80

When the inside of a neuron is negative, the voltage gated channels are what?

Back 80

Closed

Front 81

When the inside of the neuron becomes more positive, the channels what?

Back 81

Open

Front 82

Na+ and K+ voltage gated channels are located where in a neuron?

Back 82

ONLY located on the Axon

Front 83

Which ion voltage gated channel opens first?

Back 83

Na+

Front 84

Which ion voltage gated channel opens second?

Back 84

K+

Front 85

Voltage-gated channels are responsible for what?

Back 85

APs!

Front 86

Ca+2 voltage gated channels are located where in the neuron?

Back 86

Located on the axon terminals

Front 87

When do Ca+2 voltage-gated channels open when AP arrives and allows Ca+2 to do what?

Back 87

Allows Ca+2 to enter the neuron

Front 88

Ca+2 voltage-gated channels trigger what to occur?

Back 88

Triggers NT secretion

Front 89

What are the 3 overlapping functions of the nervous system?

Back 89

1. Sensory Input
2. Integration
3. Motor Output

Front 90

What is the immediate effect in the post-synaptic neuron when the chemically gated channels open?

Back 90

Graded potential!