Nervous System

Question 1

Two Main Divisions

Answer 1

1. Central Nervous System (CNS)
   - Brain + Spinal Cord
2. Peripheral Nervous System (PNS)
   - Cranial Nerves
   - Spinal Nerves
   - Further subdivided into the somatic and autonomic nervous systems

Question 2

CNS: Brain

Answer 2

• largest organ of the nervous system
• located in the cranium
• four major structures
  1. cerebrum
  2. cerebellum
  3. diencephalon
  4. brain stem
• integration of almost every physical mental activity of the body

Question 3

CNS: Spinal Cord

Answer 3

• long narrow column of neural tissue within the spinal cavity or canal
• extending from the brain stem to the second lumbar vertebra in the spinal column
• protected by the bony structure of the vertebral column
• protected and nourished by the meninges
• relay station for sending and receiving electrical signals between the brain and body

Question 4

CNS: Meninges

Answer 4

Three layers of protective membrane covering the brain and spinal cord

1. Dura mater (outermost layer)
2. Arachnoid (middle layer)
3. Pia Mater (innermost layer)

Question 5

Peripheral Nervous System (PNS)

Answer 5

Cranial Nerves
-12 pairs that emerge from the brainstem
-named according to location or function
Spinal Nerves
-38 pairs that emerge from the spinal cord
-named according to the vertebra from which they exit
Defined by the direction in which impulses travel:
-Sensory (afferent) neurons—to the CNS
-Motor (efferent) neurons—away from the CNS

Question 6

PNS: Motor Neurons send impulses:

Answer 6

• Somatic nervous system (SNS)

- Autonomic Nervous System (ANS)

Question 7

PNS: Motor Neurons send impulses; Somatic Nervous System (SNS)

Answer 7

regulates skeletal (striated) muscles (voluntary actions) such as walking and talking
(how you move)

Question 8

PNS: Motor Neurons send impulses; Autonomic Nervous System (ANS)

Answer 8

regulates visceral (smooth) muscles (involuntary actions) such as heart rate and peristalsis (relaxation of muscles and intestine or another canal, push canal forward), and secretory activity

• consists of 2 subdivisions that regulate involuntary body functions and usually oppose the action of the other:
  1. Sympathetic- fight or flight
  2. Parasympathetic- rest + digest

Question 9

PNS: Motor Neurons send impulses; Autonomic Nervous System 2 Subdivisions: Sympathetic

Answer 9

(fight or flight)

increases heart rate, constricts blood vessels, and raises blood pressure to deal with a crisis

Question 10

PNS: Motor Neurons send impulses; Autonomic Nervous System 2 Subdivisions: Parasympathetic

Answer 10

(rest + digest)

slows heart rate, increases glandular secretions, relaxes sphincters

Question 11

Cellular Structure Of The Nervous System: Neuron

Answer 11

• individual nerve cell

- interconnecting to form complicated networks called nerves that transmit electrical impulses throughout the body

Question 12

Cellular Structure Of The Nervous System: Neuroglia

Answer 12

• Glial cells that provide a supportive framework for neurons
• responsible for protecting against infection by performing phagocytosis (engulfing and digesting unwanted substances; like a Pacman)
• unable to transmit electrical impulses

Question 13

Four Types of Neuroglial Cells

Answer 13

1. Astrocytes
2. Microglia
3. Oligodendrocyte
4. Ependyma

Question 14

Neuroglial Cell: Astrocyte

Answer 14

• star-shaped cell
• numerous radiating extensions for attachment that are wrapped around the brain and capillaries
• part of the blood-brain barrier, which prevents harmful substances from diffusing into the brain

Question 15

Neuroglial Cells: Microglia

Answer 15

• small interstitial cells
• phagocytic in nature, engulfing cellular debris, waste products, and pathogens within nerve tissue
• increase in number during injury or infection as cells migrate to the infected or injured area

Question 16

Neuroglial Cells: Oligodendrocyte

Answer 16

• resembling an astrocyte but smaller with fewer extensions

- responsible for forming and maintaining the myelin sheath on neurons

Question 17

Neuroglial Cells: Ependyma

Answer 17

• cells that line the ventricles of the brain and central canal of the spinal cord
• responsible for production of cerebral spinal fluid and assistance in its circulation

Question 18

Spinal Cord Injury

Answer 18

spinal injury or disease resulting in a lack of or decrease in function or feeling
-degree of dysfunction related to site of injury on the spinal cord (higher site associated with greater dysfunction)
(the higher the injury, the worse it is; everything below is done, no function)

Question 19

Spinal Cord Injury: Signs + Symptoms

Answer 19

• loss or decrease of feeling or function
• history of trauma (such as car accident or gun shot wound)
• occasionally, exaggerated reflexes or spasms
• possible loss of motor and sensory functions in the legs and trunk (paraplegia)
• possible loss of bowel, bladder, and sexual function (quadriplegia)

Question 20

Spinal Cord Injury: Treatments

Answer 20

• restoration and stabilization of the injured spinal area
• halo brace to immobilize the head ad neck vertebrae
• decompression of compressed neurological structures
• prevention of secondary complications (contractures, pressure, ulcers)
• surgery
• drugs
• cooling of the affected portion of the spine

Question 21

Stroke

Answer 21

any disorder of the cerebral blood vessels that causes a loss of consciousness due to oxygen deprivation of brain tissue

• sometimes called cerebrovascular accident (CVA) or brain attack
• manifestations appearing on opposite side of the body from the brain hemisphere affected
  ex: left-sided weakness from injury to right hemisphere of the brain

Question 22

Types of Strokes

Answer 22

1. Ischemic
2. Intracerebral hemorrhage
3. Subarachnoid hemorrhage

Question 23

Types of Strokes: Ischemic

Answer 23

blockage of carotid arteries (arteries that supply the head and neck with oxygenated blood) by plague or thrombus, resulting in insufficient blood flow to the brain

Question 24

Types of Stroke: Intracerebral Hemorrhage

Answer 24

-rupture of vessels in the brain
-compression and destruction of brain structures from released blood
(intracerebral = cerebrum= brain)

Question 25

Types of Stroke: Subarachnoid Hemorrhage

Answer 25

- release of blood into the space surrounding the brain - commonly caused by a ruptured aneurysm (an excessive localized enlargement of an artery caused by a weakening of the artery wall) - usually fatal

Question 26

Stroke: Signs + Symptoms

Answer 26

- Hemiparesis- half weakness - Ataxia- discoordination of muscle movements - Aphasia- speaking difficulty - loss of consciousness - blurred vision - commonly preceded by a transient ischemic attack (TIA) (Signs + Symptoms of a mild stroke that resolve within 24 hours)

Question 27

Stroke: Treatment

Answer 27

- CT scan to determine the type and extent of stroke - "clot busters" to dissolve clots - Antihypertensive to control blood pressure - physical, occupational, and speech therapy

Question 28

Alzheimer's Disease (AD)

Answer 28

- most common form of dementia - interference with memory, learning, and, eventually, the ability to function - associated with neuritic "plagues" that form in a small area of the brain and, eventually, spread - definitive diagnosis only possible on autopsy (a postmortem examination to discover the cause of death or the extent of disease)

Question 29

Alzheimer's Disease (AD): Signs + Symptoms

Answer 29

- forgetfulness - diminished interest in daily activity, acquaintances, and surroundings - getting lost on familiar routes - personality changes - loss of social skills

Question 30

Alzheimer's Disease (AD): Treatments

Answer 30

- primarily supportive - altering the environment to ensure the patients safety - support of family members and caregivers - medical management, considering potential adverse effects (A harmful or abnormal result).

Question 31

Radiculopathy

Answer 31

inflammation of the nerve root associated with the spinal column - causes tingling, numbness, weakness or radiating pain starting in the spine and moving outward - result of herniated disk, degenerative changes (osteoarthritis of the spine), arthritis, fractures, bone spurs (bony projections that develop along the edges of bones) or tumors (swelling part of the body, caused by an abnormal growth of tissue) - treat with rest and anti-inflammatory medications, may need decompression surgery

Question 32

Seizure Disorders

Answer 32

characterized by sudden changes in behavior or consciousness as a result of uncontrolled electrical activity of the brain; also called epilepsies - Causes- - brain injury - congenital anomalies (a medically significant condition present at birth and resulting from developmental processes) - metabolic disorders (genetic conditions that result in metabolism problems) - brain tumors - vascular (relating to blood vessels) disturbances - genetic disorders

Question 33

Types Of Seizures

Answer 33

- Partial seizures (electrical disturbance that originates in one hemisphere of the brain) - Generalized seizures (grand-mal) (whole or larger portion of brain) - Status epilepsies (seizures for much longer than should be)