(Set 4) Physical And Electrical Properties Of The Nervous System

Front 1

Nervous System Cells (3)

Back 1

This includes
-Neurons
-Glial Cells
-Supporting elements, including meninges and blood vessels

Front 2

Neurons
-what are they designed to do (3)

Back 2

These cells are designed to receive information, process information, and generate output

Front 3

Components of Neurons:
What is the cell body called?

Back 3

This is called the soma

Front 4

Components of Neurons:
-the single nucleus of the neuron

Back 4

this area is the control center, contains genetic material

Front 5

Components of Neurons: What does the mitochondria do in the neuron?

Back 5

This organelle converts nutrients into energy

Front 6

Components of the Neuron: The rough endoplasmic reticulum does what? What is another name for it?

Back 6

Components of the Neuron:This organelle synthesizes and transports protein (Nissl body)

Front 7

Components of the Neuron: Ribosomes do what?

Back 7

Components of the Neuron: This organelle synthesizes protein

Front 8

Components of the Neuron: Golgi apparatus does what?

Back 8

Components of the Neuron: This organelle packages the neurotransmitter

Front 9

Components of the Dendrite: What kind of extension is it?

Back 9

Components of the Dendrite: This structure is a trapered cytoplasmic extension

Front 10

Components of the Dendrite: What is a Dendritic spin?

Back 10

Components of the Dendrite: This is a region where other neurons form synapses with the dendrites

Front 11

Components of the Dendrites: What is the function (2)

Back 11

These are the function of what structure.
1. Recieves information from other neurons via neurotransmitters and transmit it to the cell body
2. Produces local potentials, and if strong enough, an action potential

Front 12

Components of the Axon: where does it emerge and where does it take impulses?

Back 12

Components of the Axon: this structure emerges from the cell body at the axon hillock to conduct impulses away from the cell body

Front 13

Components of the Axon: What is the cytoplasm for it called?

Back 13

The cytoplasm for this structure is called the axoplasm

Front 14

Components of the Axon: What is the cell membrane called?

Back 14

The cell membrane for this structure is called the axoplemma

Front 15

Components of the Axon: describe the terminal end of the axon

Back 15

these structures terminate by branching into extensions with enlarged ends (terminal boutons or presynaptic terminals)

Front 16

Components of the Axon: What does the presynaptic terminal contain?

Back 16

Components of the Axon: this terminal contains small vesicles thata contain neurotransmitters

Front 17

Components of the Axon: What are the two function of the axon?

Back 17

Components: what structure has this function?
1. transmit action potential (from one nerve to another)
2. transmit proteins, neurotransmitter, empty vesicles, and other substances b/t the cell body and presynaptic terminals

Front 18

Neuron Types: Bipolar neurons: define?
-where are they found?

Back 18

Neuron Types: What type of neuron is this?
-single dendrite and single axon
-some sensory organs including the retina

Front 19

Neuron Type: Unipolar (or pseudounipolar): definition?
-it makes up ____ sensory neurons
-what simple action would cause a unipolar neuron to react?

Back 19

What type of neuron is this?
-it is a single axon and no dendrites (the axon has dendrite-like processes.
-Most sensory neurons
-when you touch something and it hurts, it is this type of neuron

Front 20

Neuron types: Multipolar neurons: definition?
-makes up most neurons what two areas?

Back 20

What type of neuron is this?
-it has several dendrites and a single axon
-most neurons in the CNS and muscle neurons are multipolar

Front 21

Action Potentials: How is information being transmitted to the brain?
How is information being transmitted to the muscle cells?

Back 21

All sensory information is transmitted which two places via action potentials?

Front 22

What important ions and type of molecules are important in transmission of an Action Potential?

Back 22

What are these ions involved in spreading?
-sodium Na+
-potassium K+
-Calcium Ca2+
-Chloride Cl-
-negatively charged protein molecules

Front 23

What happens to the cell membrane upon Depolarization?

Back 23

During what stage in an action potential does the membrane potential become less negative than the resting potential?

Front 24

What happens during the hyperpolarization stage of an action potential?
-what typically happens to the cell during this stage?

Back 24

During what stage of an action potential does the membrane become more negative than resting potential?
-during this stage the cell is typically inhibited from another action potential

Front 25

When does the resting membrane potential exist?

Back 25

When the cell is not being stimulated what state is it in?

Front 26

During the resting membrane potential, the cell membrane is permeable to what type of ion? How easy is it for other ions to pass though?

Back 26

What state is the cell in when its cell membrane is permeable to K+ ions but other molecules do not pass easily?

Front 27

During resting membrane potential, what predominant ion is on the outside of the cell? Inside?

Back 27

What state is the cell in?
Na+ is on the outside (and wants to get in due to charge)
K+ is on the inside but seeps out to balance this

Front 28

At rest, what [ions] is higher outside the neuron? inside the cell?

Back 28

What state is the cell in when:
there are relatively more sodium Na+ and cloride Cl- outside the neuron and more potassium K+ and negatively charged proteins inside the neuron?

Front 29

What three characteristics maintain the concentration difference b/t the inside and outside of the cell?

Back 29

What do these three things maintain?
1. Presence of negatively charged proteins inside the cell
2. Permeability of the cell membrane
3. Sodium-potassium pump

Front 30

When is an equilibrium created across the cell membrane?

Back 30

What happens to the cell when there is very little movement of K+ ions across the cell membrane?

Front 31

When K+ diffuses down the concentration gradient what happens to the inside of the cell (after a state of equilibrium)?

Back 31

What has to happen for the inside of the cell to have a more negative charge (after a state of equilibrium)

Front 32

Why does the cell resist K+ diffusion after it reaches equilibrium?

Back 32

At equilibrium the negative charge inside the cell membrane attracts K+ ions to the inside of the cell preventing what from occurring?

Front 33

What state is the membrane potential in when at equilibrium?

Back 33

When is the cell in its resting state?

Front 34

What is the charge of the inside of the neuron when it is in its resting membrane potential?

Back 34

When the inside of the neuron is negative relative to the outside (about -70mV) what state is it in?

Front 35

During a Local Potential, what does the stimulus cause and what region of the cell is it covering?

Back 35

Depolarization or hyperpolarization which is confined to a small region of the cell occurs due to what?

Front 36

What has to be true for an action potential to occur?

Back 36

If a local potential is large enough what happens to the cell?

Front 37

In Graded local potentials what is true about the magnitude of he depolarization or hyperpolarization?

Back 37

When the magnitude and strength are proportional during depolarization or hyperpolarization what is the local potential called?

Front 38

What happens to the magnitude of the local potential as it spreads along the cell membrane?

Back 38

The local potential Decreases as it does what?

Front 39

How far will the action potential spread along the cell membrane?

Back 39

The local potential will only spread a short distance along what?

Front 40

How can local potentials be increased ?

Back 40

Temporal and spacial summation will affect the local potentials in what way?

Front 41

What is temporal summation?

Back 41

When stimuli that occurs multiple times w/in milliseconds and is added together making the stimulus stronger, it is called ____ summation

Front 42

What is spacial summation?

Back 42

When stimuli occurs in different locations and is added together it is called ____ summation

Front 43

What has to be true for a local potential to cause an Action Potential?

Back 43

If a local potential is sufficiently strong to reach a threshold (about -55mV) what takes place?

Front 44

If a cell is stimulated to -65mV, what will happen to the action potential?

Back 44

The action potential will die out if the cell is more negative than what value?

Front 45

If a ell is stimulated to -50mV, what will happen to the action potential?

Back 45

The action potential will occur if the cell is less negative that what value?

Front 46

If the action potential transfers information from one area of the body to another, what had to have occurred?

Back 46

Depolarization will cause what to happen to the action potential in relation to the different areas of the body?

Front 47

What does the all or none principle mean when it comes to depolarization?

Back 47

When the local potential is sufficiently stimulated (about -55mV) what occurs and what is generated?

Front 48

If depolarization reaches -55mV what will occur?

Back 48

Action potential will occur when the cell is depolarized past what value in mV?

Front 49

Why wouldn't an action potential occur?

Back 49

If the action potential is more negative than -55mV what will occur?

Front 50

What is true about the size of the action potential?

Back 50

The size is the same for all ___ ___

Front 51

During the Depolarization Phase, what happens to the resting membrane potential?

Back 51

The resting membrane potential becomes more positive during what phase?

Front 52

During depolarization, what channels open initially due to a stimulus?
What ion rushes into the cell?

Back 52

-Na+ channels open when the cell is initially stimulated during the ___ phase
-Na+ rushes into the cell

Front 53

After the Na+ rushes into the cell, which ion channels open?

Back 53

-K+ channels open after what ion rushes into the cell?

Front 54

Which channels open more slowly during depolarization?

Back 54

when K+ channels open how does the K+ exit the cell?

Front 55

After depolarization occurs, what is the charge of the inside of the cell in relation to the outside?

Back 55

The inside of the cell becomes more positive than the outside of the cell after what has taken place?

Front 56

During Repolarization phase, what happens to the membrane potential?

Back 56

The membrane potential returns toward the resting membrane potential during which phase?

Front 57

During Repolarization phase the negative charge outside the cell affects what?

Back 57

The movement of Na+ ions into the cell is slowed down after its rush in during which phase?

Front 58

During Repolarization, which ion channels continue to open and which ion channels start to close?

Back 58

K+ ion channels continue to open and Na+ ion channels start to close during which phase of polarization?

Front 59

During Repolarization, when the K+ ions move out of the cell what affect does this have on the repolarization?

Back 59

A reverse in depolarization occurs when which ions move out of the cell during the end stages of the depolarization state?

Front 60

During the Afterpotential, what is the charge of the cell membrane relative to the resting membrane potential?

Back 60

The cell membrane becomes more negative than resting membrane potential during what? (starts with an A)

Front 61

Hyperpolarization occurs due to what channels staying open a bit longer than the time it takes to get the cell back to resting membrane potential.
-The mV value would be more negative than what?

Back 61

K+ channels stay open a bit too long after repolarization, causing what to happen?
-this would occur if the cell were more negative than -70mV

Front 62

The sodium potassium pump aids in what?

Back 62

Restoration of the resting level concentration of the ions across the membrane takes place due to what?

Front 63

During propagation phase an action potential in one region of the cell membrane acts as a stimulus to what?

Back 63

A stimulus to adjacent areas of the cell membrane occurs during what stage of the action potential?

Front 64

During propagation phase, as the action potential reaches each new part of the axon, it initiates what in the adjacent site?
How long does this continue?

Back 64

Electric release into adjacent sites propagate until the action potential reaches the end of the nerve during which phase?

Front 65

Larger diameter axons propagate action potentials at what rate compared to thinner ones?
Axons with a myelin sheath propagate an action potential at what rate compared to non-myelinated axons?

Back 65

Faster axon propagation occurs with what size of diameter of axon?
Faster axon propagation occurs when what structure is surrounding the axon?

Front 66

When the action potential reaches the end of an axon, what is released?
What happens after this substance is released?
What can potentially occur in an adjacent cell due to this release?

Back 66

neurotransmitter is released when the action potential arrives where?
Diffusion across the synapse takes place and potentially forms another action potential where?

Front 67

The refractory period keeps the action potential from what?

Back 67

Reversing the direction of propagation of an action potential is inhibited by what period?

Front 68

What is Absolute refractory period?
-what phases does it mostly occur?

Back 68

The period of time in which the axon is not sensitive to another stimulus (mostly depolarization and repolarization phase) is called what?

Front 69

What is Relative refractory period?
-during what part of the repolarization phase does this occur?

Back 69

A period in which only a stronger than normal stimulus can cause another action potential (during the last part of the repolarization phase) is called what?

Front 70

Clinical application: Local Anesthetics:
How does pain occur in therms of an action potential?

Back 70

Clinical application: Local Anesthetics:
When an action potential is sent from the site of pain to the CNS, what happens?

Front 71

Clinical application: Local Anesthetics:
How do local anesthetics act in order to prevent the sensory neuron from feeling pain?

Back 71

Clinical application:
What drug do we use for this?
Na+ channels are inhibited, preventing the propagation of action potentials along sensory neurons.

Front 72

Clinical application:
What type of symptoms might you have if you have too much Na+ in your blood?

Back 72

Hypernatremia

Generally not caused by an excess of sodium, but rather by a relative deficit of free water in the body. For this reason, hypernatremia is often synonymous with the less precise term, dehydration.

Symptoms: Clinical manifestations of hypernatremia can be subtle, consisting of lethargy, weakness, irritability, and edema. With more severe elevations of the sodium level, seizures and coma may occur.

Severe symptoms are usually due to acute elevation of the plasma sodium concentration to above 158 mEq/L (normal is typically about 135-145 mEq/L). Values above 180 mEq/L are associated with a high mortality rate, particularly in adults. However such high levels of sodium rarely occur without severe coexisting medical conditions.

Front 73

Clinical application:
What type of symptoms might you have if you have too much K+ in your blood?

Back 73

Hyperkalemia

Symptoms are fairly nonspecific and generally include malaise, palpitations and muscle weakness; mild hyperventilation may indicate a compensatory response to metabolic acidosis, which is one of the possible causes of hyperkalemia. Often, however, the problem is detected during screening blood tests for a medical disorder, or it only comes to medical attention after complications have developed, such as cardiac arrhythmia or sudden death.

Symptoms: During the medical history taking, a physician will dwell on kidney disease and medication use (see below), as these are the main causes. The combination of abdominal pain, hypoglycemia and hyperpigmentation, often in the context of a history of other autoimmune disorders, may be signs of Addison's disease, itself a medical emergency.

Front 74

Clinical application:
What type of symptoms might you have if you have too much Ca2+ in your blood? Too little?

Back 74

Calcium deficiency leads to chronic muscle spasms (tetany); an excess of calcium may lead to the formation of stones (calculi) in the kidney or gall bladder.

Calcium ions in animal cells are involved in regulating muscle contraction, blood clotting, hormone secretion, digestion, and glycogen metabolism in the liver. It is acquired mainly from milk and cheese, and its uptake is facilitated by vitamin D.

Front 75

Clinical application:
What type of symptoms might you have if you have too little Na+ in your blood?

Back 75

hyponatremia Symptoms

Most patients with chronic water intoxication are asymptomatic, but may have symptoms related to the underlying cause.

Severe hyponatremia may cause osmotic shift of water from the plasma into the brain cells. Typical symptoms include nausea, vomiting, headache and malaise. As the hyponatremia worsens, confusion, diminished reflexes, convulsions, stupor or coma may occur. Since nausea is, itself, a stimulus for the release of ADH, which promotes the retention of water, a positive feedback loop may be created and the potential for a vicious circle of hyponatremia and its symptoms exists.
Severe or rapidly progressing hyponatremia can result in swelling of the brain (cerebral edema), and the symptoms of hyponatremia are mainly neurological. Hyponatremia is most often a complication of other medical illnesses in which either fluids rich in sodium are lost (for example because of diarrhea or vomiting), or excess water accumulates in the body at a higher rate than it can be excreted

Front 76

Clinical application:
What type of symptoms might you have if you have too little K+ in your blood?

Back 76

Mild hypokalemia

is often without symptoms, although it may cause a small elevation of blood pressure,[2] and can occasionally provoke cardiac arrhythmias. Moderate hypokalemia, with serum potassium concentrations of 2.5-3 mEq/L, may cause muscular weakness, myalgia, and muscle cramps (owing to disturbed function of the skeletal muscles), and constipation (from disturbed function of smooth muscles). With more severe hypokalemia, flaccid paralysis, hyporeflexia, and tetany may result. There are reports of rhabdomyolysis occurring with profound hypokalemia with serum potassium levels less than 2 mEq/L. Respiratory depression from severe impairment of skeletal muscle function is found in many patients.

Front 77

Any disturbance of the chemicals involved in the action potential can cause what?

Back 77

Muscle and nerve problems are caused when there are any disturbances of the chemical involved in what?

Front 78

Hypocalcemia is defined as what?

Back 78

High extracellular Ca2+ levels causing the Na2+ to close is called what?

Front 79

What symptoms occur when you have high Ca2+ in your blood?

Back 79

Formation of stones in the kidneys and gall bladder are often caused by too much of what ion?

Front 80

What symptoms occur when you have low Ca2+ levels in your blood?

Back 80

Chronic muscle spasm (tetany) is caused by too little of what ion?

Front 81

What are three causes of Hypocalcemia?

Back 81

What condition is caused by these three things?
1. lack of calcium in diet
2. lack of Vit.D
3. decrease secretion of parathyroid hormone

Front 82

Neuroglia is defined as what? what is its function?

Back 82

What is defined as the support system for the neurons?
It functions to clean up and help support the BBB

Front 83

Glial cells are considered what of the CNS?

Back 83

What cells are defined as the neuroglia of the CNS?

Front 84

What are the 3 types of neuroglia of the CNS?

Back 84

These are 3 examples of what cells in the CNS?
1. Astrocytes
2. Oligodendrocytes
3. Microglial Cells

Front 85

What is the one and only Neuroglia of the PNS

Back 85

The Schwann Cells are the one and only type of neuroglia found where?

Front 86

Macroglia are defined as what type of cell?

Back 86

Astrocytes are what type of cell?

Front 87

An astrocyte has what type of shape?

Back 87

what type of cell has a Star-shape

Front 88

An astrocyte function to provide what function to what structures?

Back 88

What type of cell provides physical support to neurons and blood vessels?

Front 89

An astrocyte has a role in what function?

Back 89

What type of cell plays a roll in cell signaling?

Front 90

Astrocyte aid in the formation of which structure via releasing chemicals that stimulate what to form? where?

Back 90

The BBB is formed by what type of cells? these cells also stimulate tight junctions b/t endothelial cells.

Front 91

Astrocytes function to regulate what? How do they do this?

Back 91

The content of the extracellular space is regulated by what cells? These cells clean up debris such as K+ etc.

Front 92

Astrocytes transport what where?

Back 92

What type of cell transports nutrients to neurons?

Front 93

Astrocytes function in what type of development?

Back 93

The central nervous system is developed by what?

Front 94

Oligodendrocytes protect and insulate neurons located where?

Back 94

CNS neurons are protected and insulated by what type of cells?

Front 95

Cytoplasmic extensions of oligodendrocytes wrap around axons ___ time(s) to produce the myelin sheath which allows for what?

Back 95

Many wrappings of oligodendrocytes produce what type of sheaths that allow efficient conduction of action potential?

Front 96

Each oligodendrocyte supplies myelin to how many axons? It forms what type of network?

Back 96

Several axons are supplied by ___ oligodendrocyte. It forms a conduction network.

Front 97

Microglia are what type of cell? Where?

Back 97

Specialized macrophages in the CNS are called?

Front 98

Microglia can ____ hazardous material and this allow them to do what?

Back 98

Phagocytosis allows what type of cell to mobilize after injury, infection, or disease?

Front 99

Schwann cells are the only type of ___ cell in the PNS

Back 99

Glial cell

Front 100

Schwann cells function to do what in the PNS?

Back 100

Insulation of neurons in the PNS occurs by what type of cell?

Front 101

The Schwann cell wraps around the axon ___ times to produce the myelin sheath which allows for what?

Back 101

Many wraps around the axon by what cell of the PNS allows for efficient conduction of action potential?

Front 102

A single Schwann cell myelinates how many axons?

Back 102

Only one axon is myelinated by what type of cell?

Front 103

Schwann cells have what type of property?

Back 103

A phagocytic cell of the PNS that insulates?

Front 104

Unmyelinated axons rest in what? It is formed by what cell?

Back 104

Invaginations formed by oligodendrocytes or Schwann cells will cause an axon to be what?

Front 105

In unmyelinated axons, the action potential will propagate how?

Back 105

The action potential will propagate along the entire axon membrane when the axon is what?

Front 106

Axons that are surrounded repeatedly by a myelin sheath are considered what?

Back 106

Myelinated axons are surrounded how?

Front 107

What are Nodes of Ranvier? Where are they formed? What do they contain?

Back 107

Interruptions in the myelin sheath that contain high densities of Na+ and K+ channels are called what?

Front 108

Saltatory conduction occur when what takes place in regard to action potentials?

Back 108

Jumps from one note of Ranvier to the next causing the action potential to travel much faster than in an unmyelinated axon is called what?

Front 109

The speed of conduction depends on what two aspects of the axon?

Back 109

Myelination and diameter of the axon influences what in regard to action potential?

Front 110

How do myelinated axons conduct action potentials more rapidly?

Back 110

Saltatory conduction functions how in regard to action potential?

Front 111

Larger diameter axons conduct action potential more rapidly due to what factor?

Back 111

Decreased resistance is a factor that does what for an action potential?

Front 112

MS is an autoimmune disease in which AB attack myelinated nerves where?

Back 112

In MS, what is affected in the CNS

Front 113

All glial cells in what aspect of the nervous system are affected in MS?

Back 113

CNS cells that are affected in MS are?

Front 114

Oligodendrocytes are often destroyed in MS which does what?

Back 114

In MS, the repair process of the myelin sheath is compromised how?

Front 115

What type of cells are stimulated to feed on the myelin debris in MS?

Back 115

Microglial cells do what to myelin debris in MS?

Front 116

In MS, what type of cell proliferates? what is this called?

Back 116

Astrocytes will do what in MS? Gliosis

Front 117

Loss of saltatory conduction occurs when what is lost in MS?
This causes what in regard to the action potential?

Back 117

When there is a loss of myelin what is lost?
Action potential can no longer travel down the axon.

Front 118

After time, ___ channels that were concentrated at the Nodes of Ranvier redistribute themselves. This causes what?

Back 118

Na+ channels from the Nodes of Ranvier will do what when myelin is lost. What gets slower?

Front 119

What can happen to the axon in MS? When does irreversible neurological damage occur?

Back 119

In MS axons can be sparred, partially damaged, or totally destroyed. Total destruction of the axon causes what?

Front 120

Ocular symptoms of MS include what (4)? Which age group is affected most frequently?

Back 120

These are ocular symptoms associated with what demyelinating disease?
1. optic neuritis
2. inflammation of optic nerve
3. pain w/ eye movement
4. photoopsia - flashing of lights in vision

Front 121

Ocular symptoms of MS include which EOMs and why?

Back 121

SR, MR b/c they are hooked into the nerve sheath

Front 122

Etiology of MS include"
Age:
Mean Age:
Gender:
Prevalence:

Back 122

This etiology of this includes what condition?
Age: 20-50
Mean: 30-35
Gender: women
Prevalence: 115/100,000

Front 123

Symptoms of MS:
-what % of pt. have pain or discomfort around the eye w/ eye movement?

Back 123

90% of MS pt. complain of what ocular symptom?

Front 124

The ____ of decreased vision associated with MS varies widely and it is usually ____?

Back 124

Degree of Monocular vision has what type of range?

Front 125

Signs of Ocular Dysfunction in 2/3 of pt with MS are ______ optic neuritis where the optic disc looks ____

Back 125

what fraction of pt with MS have retrobulbar optic neuritis? What in the exam looks normal?

Front 126

Other ocular signs of MS include what 5 things?

Back 126

What condition is associated with these ocular dysfunction?
1. APD
2. Decreased visual acuity
3. Acquired color loss
4. Visual field deficit
5. Decreased contrast sensitivity

Front 127

In MS, MRI determine if what ocular dysfunction is present?
What else can it determine?
What does it assist in?

Back 127

what test is used to determine retrobulbar optic neuritis in MS. Plaques are also seen though it and it assists in prognosis.

Front 128

What is the best form of MRI to use for MS prognosis?
what did T1 show?
what did T2 show?

Back 128

MRI flair
T1 with contrast - shows optic nerve is inflamed
T2 was bright CSF in sulci

Front 129

Treatment/Prognosis for MS ocular dysfunction
-what % spontaneously recover vision to 20/40
-what amount of time does it take for this to occur?
-why

Back 129

90% recover in 3-5 (or 4-6) weeks

Front 130

A 3 day course of IV corticosteroids followed by 15 days of oral prednisone and then interferon beta-1a lowers the risk of developing MS over ___ yrs to ___% instead ___% risk in untreated pt.

Back 130

3 yrs
35%
50%