Nervous system part one

Question 1

Can the spinal cord make descisions?

Answer 1

Yes; reflexes, can choose to send messages to brain or not

Question 2

What are the 2 divisions of the nervous system?

Answer 2

1. Central nervous system
2. Peripheral nervous system

Question 3

What are the three systems in the peripheral nervous system

Answer 3

1. Somatic nervous system
2. Autonomic nervous system
3. Enteric nervous system

Question 4

What are the two divisions of the PNS?

Answer 4

1. Sensory (afferent) division
2. Motor (efferent) division

Question 5

What is the CNS and what does it contain?

Answer 5

-The integration and command center
-Contains the brain and spinal cord

Question 6

What system are the crainal and spinal nerves a part of?

Answer 6

PNS

Question 7

How many crainial and spinal nerves are there?

Answer 7

-12 pairs of crainial nerves
-31 pairs of spinal nerves

Question 8

What nervous system within the PNS is voluntary?

Answer 8

The somatic nervous system

Question 9

Where do sensory neurons convery information to in the somatic nervous system?

Answer 9

The CNS

Question 10

Where do motor neurons conduct impulses from and to in the somatic nervous system?

Answer 10

Motor neurons conduct impulses from the CNS to skeletal mucles only

Question 11

Where does sensory information come from?

In the autonomic nervous system

Answer 11

From visceral organs (lungs, heart, kidneys)

Question 12

Where do motor neurons from the CNS transmit impulses to in the autonomic nervous system?

Answer 12

To cardiac, smooth muscle, glands

Question 13

What are the two main divisions of the motor neurons in the autonomic nervous system?

Answer 13

1. Sympathetic division
2. Parasympathetic division

Question 14

True or false?

The effectors of the autonomic nervous sytem recieve innervation from both branches and have opp. actions.

Answer 14

True

Question 15

What is the function of the sensory neurons in the enteric nervous system?

Answer 15

Monitors chemical changes and the stretching of the walls of the GI tract

Question 16

What is the function of the motor neurons in the enteric nervous system?

Answer 16

Controls contractions (peristalsis and segmentations) and secretions (acids in stomach, hormones, ect.)

Question 17

What are the 3 nervous system functions?

Answer 17

1. Sensory function
2. Integration function
3. Motor function

Question 18

How does the nervous system regualte its sensory function?

Answer 18

-By monitoring changes from inside and outside of the body
-Retrieves stimulus/sensory input

Question 19

How does the nervous system regulate its integration function?

Answer 19

-Interprets senstory info and makes descisions

Question 20

How does the nervous system regulate its motor function?

Answer 20

-Generates a response
-Activates effectors (muscle to contract or organ to secrete)

Question 21

Can neurons replicate?

Answer 21

-Yes, in the PNS; NOT the CNS

Question 22

What is the function of the neurons?

Answer 22

Generates and propagates nerve impulses

Question 23

What is more plentiful; neurons or neuralgia, and by how much?

Answer 23

Neuralgia, around 25x

Question 24

True or false?

Neurons are smaller than neuroglia

Answer 24

False, neuroglia is smaller and more plentiful than neurons

Question 25

Can neuralgia transmit nerve signals?

Answer 25

No

Question 26

What is the function of neuralgia?

Answer 26

-Support, nourish and protect neurons

Question 27

What are the 3 parts of a neuron?

Answer 27

1. Cell body 2. Dendrites 3. Axon

Question 28

What does the cell body contain?

Answer 28

The nucleus

Question 29

What part of the neuron is responsible for descision making?

Answer 29

The cell body

Question 30

What is the recieving/input part of a neuron?

Answer 30

The dendrites

Question 31

What is the function of the axons?

Answer 31

Propagates nerve impulses to antoehr neuron, muscle or gland

Question 32

Label the blue boxes in the image

Answer 32

Question 33

How are neurons classified?

Answer 33

**By thier function**; classified according to the direction of nerve impulses travel with respect to the CNS

Question 34

What are the 3 different functional classifications of neurons?

Answer 34

1. Sensory neurons (afferent neurons) 2. Motor neurons (efferent neurons) 3. Interneurons

Question 35

Which way do sensory nerve impulses travel?

Answer 35

Toward the CNS

Question 36

Which way do motor nerve impulses travel?

Answer 36

Carried away from the CNS

Question 37

Where are interneurons located?

Answer 37

Between the sensory and motor neurons

Question 38

What percentage of neurons do interneurons account for in the body?

Answer 38

90%

Question 39

What is the function of interneurons?

Answer 39

They are the descision makers

Question 40

What is neuroglia?

Answer 40

The glue that holds the nervous tissue together

Question 41

What are the 6 types of neuroglia?

Answer 41

1. Astrocytes 2. Oligodendrocytes 3. Microglia 4. Ependymal cells 5. Schwann cells 6. Satellite cells

Question 42

What types of neuroglia are located in the CNS?

Answer 42

1. Astrocytes 2. Oligodendrocytes 3. Microglia 4. Ependymal cells

Question 43

What type of neuroglia are located in the PNS?

Answer 43

1. Schwann cells 2. Satellite cells

Question 44

WHat is the function of the schwann cells?

Answer 44

-Form the myelin sheath -Regenerate nerve fiber

Question 45

What is the function of the satellite cells?

Answer 45

They surround the neuron cell bodies in the ganglia

Question 46

Where does an action potential begin?

Answer 46

At the axon hillock

Question 47

What is the function of the myelin sheath?

Answer 47

-To protect and electrically insulate the fiber -They increase the transmittion of the nerve impulse

Question 48

What makes up the myelin sheath in the CNS?

Answer 48

The Oligodendrocytes

Question 48

What makes up the myelin sheath in the PNS?

Answer 48

The schwann cells

Question 49

What is the function of the nodes of ranvier?

Answer 49

Allows the electrical impulse to jump from node to node

Question 50

What does multiple sclerosis result from?

Answer 50

Demyelination

Question 51

What are cell bodies grouped together in the PNS known as?

Answer 51

Ganglion

Question 52

What are cell bodies grouped together in the CNS known as?

Answer 52

Nucleus

Question 53

What are axons bundled together known as in the PNS?

Answer 53

Nerve

Question 54

What are axons bundled together known as in the CNS?

Answer 54

Tract

Question 55

What makes up the gray matter in the spinal cord

Answer 55

1. Neuronal cell bodies 2. Dendrites 3. UN myelinated axons 4. Axon terminals 5. Neuroglia

Question 56

What makes up the white matter in the nervous sytem?

Answer 56

Myelinated axons

Question 57

# True or false? The majority of negative charges are outside the membrane and the majority of positive charges are inside the membrane.

Answer 57

False; There is a build up of negative charges inside the membrane and positive charges outside the membrane

Question 58

What is the resting membrane potential numerically?

Answer 58

-70mV

Question 59

When cells are polarized, do they have a membrane potential?

Answer 59

Yes

Question 60

Why is the resting membrane potential negative inside?

Answer 60

Due to the excess of positive charges on the outside and negative on the inside

Question 61

What is the cell more permeable to; potassium or sodium?

Answer 61

Potassium

Question 62

How does the sodium potassium pump maintain balance?

Answer 62

-Lets out 3 sodium ions -Takes in 2 potassium ions

Question 63

What are ion channels?

Answer 63

Openings in the membrane that allow specific ions to move across according to the electrochemical gradient

Question 64

How do channels control the movment of ions?

Answer 64

Through gates

Question 65

What are the 4 types of channels in the nervous system?

Answer 65

1. Leak channels 2. Chemically gated/ligand-gated channels 3. Mechanically gated channels 4. Voltage-gated channels

Question 66

What parts of the neuron have leak channels?

Answer 66

Dendrites, cell bodies and axons for ALL TYPES of neurons

Question 67

What are the majority of leak channels permeable to?

Answer 67

Potassium

Question 68

What parts of the neuron have chemically gated channels?

Answer 68

1. Dendrites of some sensory neurons (pain receptors) 2. Dendrites and cell bodies of interneurons and motor neurons

Question 69

How do chemically gated channels work in the nervous system?

Answer 69

-Open or close to due a chemical stimulus -Neurotransmitters (acetocholine) opens channels to allow sodium and Ca ions in and potassium ions out

Question 70

How do mechanically gated channels work in the nervous system?

Answer 70

Gates open or close channels due to vibrations, stretching, or pressure

Question 71

Where are mechanically gated channels found in the body?

Answer 71

1. Auditory receptors 2. Internal organ stretch receptors 3. Pressure receptors in the skin

Question 72

How do voltage gated channels work in the nervous sytem?

Answer 72

Gates open in response to a change in the resting membrane potential

Question 73

Through what type of channel do action potentials move in all neurons?

Answer 73

Through voltage gated channels

Question 74

What are the 2 ways that neurons communicate with eachother using electrcical signals?

Answer 74

1. Graded potentials 2. Action potentials

Question 75

# True or false? Graded potentials trigger A.P.

Answer 75

True

Question 76

What effect do graded potentials have on a cell in the nervous sytem?

Answer 76

-Causes a small deviation in the resting membrane potential and can cause the cell to be more or less polarized -This stimulates mechanically gates and chemically gated channels to open/close

Question 77

What does "graded" mean in the context of the nervous system?

Answer 77

Singal varies in size

Question 78

Where do graded potenatials mainly occur?

Answer 78

-Dendrites and cell bodies

Question 79

# True or false? Graded potentials travel for short distances.

Answer 79

True

Question 80

# True or false? Action potentials travel short distances due to the decrease in signal.

Answer 80

False; action potentials travel long distances without losing the strength of the signal

Question 81

Where is the trigger zone for action potentials in neurons?

Answer 81

Often the axon hillock

Question 82

What are action potentials?

Answer 82

Rapidly occuring sequences of events that decrease and reverse the membrane potential and the restore it back to normal

Question 83

What are the 2 phases caused by action potentials?

Answer 83

1. Depolarizing phase 2. Repolarizing phase

Question 84

Describe breifly what occurs during the depolarizing phase

Answer 84

Sodium channels open and membrane depolarizes due to sodium levels inside the cell

Question 85

Breifly describe what happens during the repolarizing phase:

Answer 85

-Potassium channels ooen and potassium leaves the cell, therefore repolarizing

Question 86

# True or false? In order for the cell to repolarize, a threshold level is needed.

Answer 86

True

Question 87

State the all or nothing principle:

Answer 87

If a stimulus reaches threshold, the A.P. is always the same

Question 88

# True or false? A larger graded potential results in a larger action potential.

Answer 88

FALSE

Question 89

Label the blue boxes

Answer 89

Question 90

How is resting membrane potential obtained?

Answer 90

Through leak channels

Question 91

What is a synapse?

Answer 91

The site of communication between 2 neurons or between a neuron and an effector cell

Question 92

Where are the majority of synapses located?

Answer 92

Axodendndritic-between two dendrites

Question 93

What are the 2 types of synapses?

Answer 93

1. Chemical synapses 2. Electrical synapses

Question 94

What is the space between neurons called?

Answer 94

The synaptic cleft

Question 95

Do neurons touch?

Answer 95

No, but are very close

Question 96

Can action potentials jump across chemical synapses?

Answer 96

No

Question 97

Describe the process of how nerve impuses travel from nerve to nerve:

Answer 97

1. Presynaptic neurons relases a neurotransmitter 2. Neurotransmitter difuses through cytoplasm and bind with the membrane of the post synaptic neuron 3. The chemical stimulus causes the chemically gated channels to open and produces an electrical signal in the post synatic neuron

Question 98

How long is the synaptic delay?

Answer 98

Around .5 msec

Question 99

What are the advantages of electrical synapses?

Answer 99

1. Faster commuication 2. Synchronization-heartbeat, peristalsis

Question 100

How are action potentials conducted?

Answer 100

Directly between adjacent neurons (gap junctions) via channel protiens through tubuar connexons

Question 101

Where are electrical synapses most common?

Answer 101

Common in the brain, visceral smooth muscle and cardiac muscle

Question 102

Label the blue boxes:

Answer 102