CNS Class 1 - Cell Types, Injury & Death

Question 1

The body’s command center that originates from the brain. It controls movement, thoughts and automatic responses to the outside world, as well as other body systems and processes, such as digestion, breathing and sexual development.

Answer 1

Nervous System

Question 2

The nervous system can be separated into the _______ nervous system and __________ nervous system.

Answer 2

Central Nervous System (CNS)
Peripheral Nervous System (PNS)

Question 3

A division of the nervous system made up of the brain and spinal cord that receives, interprets and responds to body tissues.

Answer 3

Central Nervous System (CNS)

Question 4

The CNS is responsible for ____________ function and regulation of the autonomic nervous system, which is sometimes called the __________ nervous system as it pertains to basic physiological functions, like growth, respiration, sleep, digestion, excretion and homeostasis.

Answer 4

Hypothalamus
Vegetative Nervous System

Question 5

The CNS is responsible for learning, cognition and memory, which help form our ___________.

Answer 5

Personality

Question 6

Individual differences in characteristic patterns of thinking, feeling and behaving.

Answer 6

Personality

Question 7

A division of the nervous system made up of everything outside the brain and spinal cord, which includes the cranial nerves, spinal nerves and their roots and branches, peripheral nerves and neuromuscular junctions.

Answer 7

Peripheral Nervous System (PNS)

Question 8

The boundary between the CNS and PNS is the ______________ _______.

Answer 8

Intervertebral Foramen

Question 9

The 2 categories of cells in the CNS are _______ and _________.

Answer 9

Neurons
Neuroglia

Question 10

Name the parts of a neuron, as numbered in the following image.

Answer 10

1) Cell Body
2) Dendrites
3) Axon
4) Oligodendrocyte
5) Myelin Sheath
6) Synaptic End Bulbs
7) Axon Terminal
8) Node of Ranvier

Question 11

The basic working unit of the brain. The parenchymal cell designed to transmit information to other nerve cells, muscle or gland cells.

Answer 11

Neuron (aka. Nerve Cell)

Question 12

Functional cells of an organ.

Answer 12

Parenchymal Cells

Question 13

Structural cells of an organ.

Answer 13

Stromal Cells

Question 14

Part of a neuron that contains the nucleus and cytoplasm.

Answer 14

Cell Body (aka. Soma, Perikaryon)

Question 15

Part of a neuron that extends from the cell body and often gives rise to many smaller branches before ending at the nerve terminals.

Answer 15

Axon

Question 16

Part of a neuron that extend from the cell body and receive messages from other neurons.

Answer 16

Dendrites

Question 17

Neurons send signals using ______ ___________, which are shifts in the neuron’s potential electric energy caused by the flow of charged particles in and out of the membrane of the neuron.

Answer 17

Action Potentials (APs)

Question 18

When an action potential is generated, it’s carried along the axon to a ___________ ending. They can trigger both chemical and electrical ________.

Answer 18

Presynaptic
Synapses

Question 19

The contact points where one neuron communicates with another. The dendrites are covered with ________ formed by the ends of axons from other neurons.

Answer 19

Synapses

Question 20

What are the 4 types of neurons?

Answer 20

1) Unipolar
2) Bipolar
3) Pseudounipolar
4) Multipolar

Question 21

A type of neuron that has only one process and is mostly found in invertebrates.

Answer 21

Unipolar

Question 22

A type of neuron that is usually oval in shape and contains two processes, a dendrite that receives signals usually from the periphery and an axon that propagates the signal to the CNS.

Answer 22

Bipolar

Question 23

_______ neurons are found in sensory organs, such as retina, olfactory epithelium and the auditory system.

Answer 23

Bipolar

Question 24

A type of neuron that has two processes which fuse during their development into one short common axon. This axon splits into one branch that terminates in the periphery while the second branch terminates in the spinal cord. Stimuli from the periphery will bypass the cell body and reach the axon terminal without delay.

Answer 24

Pseuodounipolar

Question 25

______________ and bipolar cells make up all the primary sensory neurons in the PNS.

Answer 25

Pseuodounipolar

Question 26

Pseudounipolar neurons are found in sensory _______ of cranial and spinal nerves.

Answer 26

Ganglia

Question 27

A type of neuron characterized by many dendrites that can originate from different regions of a cell body. They vary greatly in size, shape and complexity of their dendritic tree, and they represent the most common type of neuron in the CNS.

Answer 27

Multipolar

Question 28

A diverse class of cells that provide developmental, physiological and metabolic support for neurons. They are responsible for maintaining homeostatic control and immune surveillance in the nervous system.

Answer 28

Neuroglia (aka. Glia, Glial Cells)

Question 29

In both the PNS and CNS, there are neuroglia that __________ the axons.

Answer 29

Myelinate

Question 30

A greatly extended and modified plasma membrane wrapped around the nerve axon in a spiral fashion. It functions to both insulate the axon and speed up electrical conduction.

Answer 30

Myelin Sheath

Question 31

T/F - Each myelin-generating cell furnishes myelin for only one segment of any given axon.

Answer 31

True

Question 32

The periodic interruptions where short portions of the axon are left uncovered by myelin, which are critical to the functioning of myelin.

Answer 32

Nodes of Ranvier

Question 33

_______ cells myelinate axons in the PNS.

Answer 33

Schwann Cells

Question 34

_________ cells regulate nutrient and neurotransmitter levels around neuron cell bodies in ganglia.

Answer 34

Satellite Cells

Question 35

An immune system cell that removes cell debris, wastes and pathogens via phagocytosis in the CNS.

Answer 35

Microglia

Question 36

The 3 main functions of __________ are: - Maintain the blood brain barrier and preserve chemical environment by recycling ions and neurotransmitters - Involved in gliosis - Provide structural support

Answer 36

Astrocytes

Question 37

A structure that protects neurons from toxins in the blood. It detects elements in blood that may be damaging to the neuron by closing gates, neutralizing the toxin or by dying.

Answer 37

Blood Brain Barrier (BBB)

Question 38

T/F - The BBB is sensitive to all toxins, as it has evolved to determine toxic products, organic substances, foreign materials and metabolic wastes.

Answer 38

False - The BBB is sensitive to SOME toxins BUT NOT OTHERS, as it has evolved to determine toxic products, organic substances, foreign materials and metabolic wastes.

Question 39

The BBB is not so good at recognizing contemporary chemicals and _______.

Answer 39

Alcohol

Question 40

The restrictive nature of the BBB provides an obstacle for drug delivery to the CNS, and thus, major efforts have been made to generate methods to modulate or bypass it for delivery of ____________.

Answer 40

Therapeutics

Question 41

A response to CNS damage and may persist for weeks or months after brain injury, occurring after infarct and is associated with infections and neoplasm, as well as demyelinating, toxic and metabolic diseases.

Answer 41

Gliosis (aka. Astrocytosis, Astrocytic Gliosis)

Question 42

Astrocytes migrate to the site of neuronal death, clustering together to create a soft scar structure known as a _______.

Answer 42

Gliosis

Question 43

The CNS does not use ___________ (second intention) repair, because this would result in an overly stiff, irritating and compressive scar.

Answer 43

Collagenous

Question 44

The astrocytes remain alive for __ to __ years, adding to the gliosis if necessary, and possibly alerting ___________ if an immune response is needed.

Answer 44

1-2 years Macrophages

Question 45

T/F - Eventually the astrocytes die, but still remain in place as a soft scar.

Answer 45

True

Question 46

It is thought that the glial scar limits _____ and prevents neuronal regeneration in the CNS by blocking regenerating axons from entering the damaged areas.

Answer 46

Edema

Question 47

________________ myelinate axons in the CNS and provide an overall structural framework.

Answer 47

Oligodendrocytes

Question 48

Resulting lesions of demyelinated neurons that show up as grey spots on imaging.

Answer 48

Plaques

Question 49

_________ cells line ventricles in the brain and the central canal in the spinal cord, and are involved in the production of cerebrospinal fluid.

Answer 49

Ependymal Cells

Question 50

Acute or chronic injury to the CNS, typically leading to irreversible damage. Some neurons die, and those that survive generally fail to grow new axons and re-establish synaptic connections.

Answer 50

Neuronal Resiliency

Question 51

A common but poorly understood characteristic of ________ __________ is that specific neuronal types are disproportionately affected even though they all share the same causes of injury.

Answer 51

Neuronal Resiliency

Question 52

Match the following examples with their cell types: 1) Hepatocytes 2) Neurons 3) Epithelial Cells A) Labile Cells B) Stable Cells C) Permanent/Fixed Cells

Answer 52

1) Hepatocytes ~ B) Stable Cells 2) Neurons ~ C) Permanent/Fixed Cells 3) Epithelial Cells ~ A) Labile Cells

Question 53

______ cells continue to divide and replicate throughout life, replacing cells that are continually being destroyed.

Answer 53

Labile Cells

Question 54

______ cells normally stop dividing when growth ceases. They are capable of undergoing regeneration when confronted with an appropriate stimulus and are capable of reconstituting the tissue of origin. They will increase or decrease in number in response to usage or need.

Answer 54

Stable Cells

Question 55

T/F - Neuroglia are labile cells, therefore are capable of reproduction to replace dead cells.

Answer 55

False - Neuroglia are STABLE cells, therefore are capable of reproduction to replace dead cells.

Question 56

In situations where there is recurring cell death in ______ tissues, the replacement mechanism may begin to fail, leading to conditions like Multiple Sclerosis.

Answer 56

Stable

Question 57

_________/_____ cells cannot undergo mitotic division and do not normally regenerate. Once destroyed, they are replaced by fibrous scar tissue that lacks the functional characteristics of the destroyed tissue.

Answer 57

Permanent/Fixed Cells

Question 58

When people improve after CNS injuries, it is due to compensation via _______________ from other surrounding cells.

Answer 58

Neuroplasticity

Question 59

T/F - Once a neuron is killed, it cannot be replaced .

Answer 59

True

Question 60

The ability of the brain to form and recognize synaptic connections, especially in response to learning, experience or following injury.

Answer 60

Neuroplasticity

Question 61

To immediately kill a neuron, the ____ ____ must be destroyed. If only the ____ is damaged, there is potential for repair, at least in peripheral nerves.

Answer 61

Cell Body Axon

Question 62

The most abundant excitatory neurotransmitter released by nerve cells in the brain. Too much has been associated with neurological diseases, such as Parkinson's and ALS.

Answer 62

Glutamate

Question 63

A layer of connective tissue surrounding each axon.

Answer 63

Endoneurium

Question 64

Peripheral nerve axon injuries are classified by the level of injury to which 3 structures?

Answer 64

1) Axon 2) Myelin Sheath 3) Endoneurium

Question 65

Name the grades of a nerve injury, as numbered in the following image.

Answer 65

1) Neurapraxia 2) Axonotmesis 3) Neurotmesis

Question 66

Refers to when the axon is damaged, but the endoneurium and most of the surrounding myelin sheath is largely still intact.

Answer 66

Axonotmesis

Question 67

T/F - There is potential for the axon to grow back with axonotmesis, as long as the injury is not too close to the cell body.

Answer 67

True

Question 68

After nerve injury, the axon first undergoes _________ degeneration.

Answer 68

Wallerian Degeneration (aka. Anterograde, Orthograde)

Question 69

An active process of degeneration of the distal end of an axon that occurs between 7 to 21 days after the injury.

Answer 69

Wallerian Degeneration (aka. Anterograde, Orthograde)

Question 70

With Wallerian degeneration, the distal segment of the axon dies to the nearest ____ of _______. Once degeneration is complete, several axonal sprouts grow from the proximal segment, with any errant sprouts kept in line by the intact ___________.

Answer 70

Node of Ranvier Endoneurium

Question 71

T/F - The axon can grow back at a rate of approximately 2.5 mm per day, starting within 24 hours of the initial injury.

Answer 71

False - The axon can grow back at a rate of approximately 1.5 MM per day, starting within 24 hours of the initial injury.

Question 72

Refers to if the endoneurium is no longer intact and surrounding myelin sheath is more severely damaged. Axonal regeneration is unlikely because the endoneurium is not there to contain and guide the axonal sprouts, therefore surgery is required to try to recover some function.

Answer 72

Neurotmesis

Question 73

T/F - Injured nerve cells in the CNS typically do not regenerate.

Answer 73

True

Question 74

Proteins expressed by oligodendrocytes that limit axon regeneration.

Answer 74

Inhibitory Molecules

Question 75

A physical barrier to regeneration that forms after CNS injury and also contains inhibitory molecules that impede axon growth.

Answer 75

Astroglial Scar (aka. Astrocytosis, Gliosis)

Question 76

CNS neurons do not __________ growth-associated genes to the same extent as do PNS neurons. Consequently, their ability to regenerate is limited even in the absence of inhibitors.

Answer 76

Upregulate

Question 77

If a CNS axon or dendrite is fatally injured, or if a PNS axon is damaged too close to the cell body, the proximal segment of the axon will undergo __________ degeneration toward the cell body. The cell body may or may not die, but the cell cannot transmit.

Answer 77

Retrograde Degeneration

Question 78

T/F - Retrograde degeneration occurs exclusively from anterograde degeneration.

Answer 78

False - Retrograde degeneration occurs IN ADDITION TO anterograde degeneration.

Question 79

CNS cells are highly metabolically active for which they are dependent on _____ supply. The brain uses __ to __% of available oxygen or glucose at any given time.

Answer 79

Blood Supply 20-30%

Question 80

CNS cells are especially sensitive to reduction in ______ and variations in blood _____.

Answer 80

Oxygen Blood Sugar

Question 81

With loss of oxygen, permanent damage usually begins to occur within __ to __ minutes.

Answer 81

4-10 minutes

Question 82

The common causes of cell _____ in the CNS due to decreased ______ supply are: - In Utero - Birth-Related - Fractures/Dislocations of Supporting Bones - Compression - Direct Trauma - Concussion/Contusion - Autoimmune Conditions - Vascular Lesions - Infection - Poisons/Toxins

Answer 82

Cell Death Oxygen Supply

Question 83

Cell death in the CNS caused __ _____ may be due to: - Genetic or congenital defect - Injury to fetus - Maternal high fever/illness (especially viral) - Maternal drug/alcohol exposure - Intrauterine infections - Thyroid dysfunctions in mother/fetus

Answer 83

In Utero

Question 84

Cell death in the CNS that is _____-_______ may be due to: - Birth canal hypoxia - Cord wrapped around neck of fetus - Direct trauma from forceps used

Answer 84

Birth-Related

Question 85

Cell death in the CNS can be caused by __________ or ____________ of supporting bones, such as the skull or vertebrae.

Answer 85

Fractures/Dislocations

Question 86

Cell death in the CNS caused by ___________ may be due to: - Edema - Hematoma - Tumour

Answer 86

Compression

Question 87

T/F - CNS cells are very adversely affected by even small tumors or accumulations of fluid because of tight encasement in protective bony structures.

Answer 87

True

Question 88

Cell death in the CNS caused by ______ ______ may be due to: - Auto accident - Fall - Sports injury - Penetrating injury

Answer 88

Direct Trauma

Question 89

A concussion or contusion injury that occurs both at the site of trauma and the opposite side of the brain.

Answer 89

Coup-Contrecoup

Question 90

Cell death in the CNS caused by __________ __________ include: - Multiple Sclerosis attacking oligodendrocytes - Diabetes resulting in blood sugar fluctuations leading to brain damage or seizures - Lupus (SLE) causing seizures or psychoses

Answer 90

Autoimmune Conditions

Question 91

Cell death in the CNS caused by ________ _______ may be due to: - Stroke (occlusive or hemorrhagic infarction) - Disorders creating hypoxic conditions (e.g. atherosclerosis in cerebral vasculature)

Answer 91

Vascular Lesions

Question 92

Cell death in the CNS caused by _________ can be viral, bacterial or fungal (e.g. Candida).

Answer 92

Infection

Question 93

_____________ infections common in the CNS are named by location and/or organism type.

Answer 93

Opportunistic

Question 94

Match the following names with their organism type: 1) Granulomatous 2) Lymphocytic 3) Pyogenic A) Common Bacteria B) Viruses C) Fungi, Yeast, Superbacteria

Answer 94

1) Granulomatous ~ C) Fungi, Yeast, Superbacteria 2) Lymphocytic ~ B) Viruses 3) Pyogenic ~ A) Common Bacteria

Question 95

Match the following names with their location in the CNS: 1) Meningitis 2) Spinal Meningitis 3) Encephalitis 4) Myelitis A) Brain Parenchyma B) Brain Protective Membranes C) Spinal Cord Parenchyma D) Spinal Cord Membranes

Answer 95

1) Meningitis ~ B) Brain Protective Membranes 2) Spinal Meningitis ~ D) Spinal Cord Membranes 3) Encephalitis ~ A) Brain Parenchyma 4) Myelitis ~ C) Spinal Cord Parenchyma

Question 96

Cell death in the CNS caused by _______ or ______ may be due to: - Drugs (prescription and recreational) - Chemicals of various types - Alcohol - Metals (e.g. mercury, lead, aluminum) - Carbon monoxide

Answer 96

Poisons or Toxins

Question 97

Poisons or toxins usually impair the cell's ability to uptake or use ______ and the mechanism appears to be damaging or blocking receptor sites on the cell membrane.

Answer 97

Oxygen

Question 98

Neurons are: A) Labile Cells B) Permanent/Fixed Cells C) Stable Cells D) None of the Above

Answer 98

B) Permanent/Fixed Cells

Question 99

Neuroglia are: A) Labile Cells B) Permanent/Fixed Cells C) Stable Cells D) None of the Above

Answer 99

C) Stable Cells

Question 100

The ability of the brain to form and reorganize synaptic connections is called: A) Synaptic Rehab B) Neurotmesis C) Axonotmesis D) Neuroplasticity

Answer 100

D) Neuroplasticity

Question 101

If a CNS axon or dendrite is fatally injured, the proximal segment of the axon will undergo: A) Retrograde Degeneration B) Backwards Deformity C) Astrocytosis D) Neurotmesis

Answer 101

A) Retrograde Degeneration

Question 102

Which of the following could compress CNS cells? A) Edema B) Hematoma C) Tumor D) All of the Above

Answer 102

D) All of the Above

Question 103

This image is depicting: A) Vascular Lesion B) Bone Dislocation C) Coup-Contrecoup D) Infection

Answer 103

C) Coup-Contrecoup

Question 104

An infection in the brain's protective membranes is called: A) Encephalitis B) Meningitis C) Myelitis D) Lymphocytic

Answer 104

B) Meningitis

Question 105

An infection in the brain caused by a virus is called: A) Myelitis B) Granulomatous C) Pyogenic D) Lymphocytic

Answer 105

D) Lymphocytic

Question 106

Which of the following could impair the brain's ability to use oxygen? A) Carbon Monoxide B) Aluminum C) Alcohol D) All of the Above

Answer 106

D) All of the Above

Question 107

CNS cell death usually involves: A) Decreased Oxygen B) Increased Calcium C) Decreased Serotonin D) Excessive Sodium

Answer 107

A) Decreased Oxygen