1

2

Epidural Space: out here between the dura mater and the bone

The sub arachnoid space: contains the spinal fluid

3

4

Spinal Cord: Gray Matter

Anterior Horn

Posterior Horn

Central Canal

Posterior gray horns contain somatic and visceral sensory nuclei

Anterior gray horns contain somatic motor nuclei

Lateral gray horns (only located in the thoracic and lumbar segments) contain visceral motor nuclei

5

Spinal Cord: White MatterPosterior White Column

Lateral White Column

Anterior White Column Anterior

Median Fissure

Each column contains tracts (axons)

Ascending tracts carry sensory information from the body toward the brain

Descending tracts carry motor commands to the spinal cord

What do we know about the nervous system?

Central Nervous System

Peripheral Nervous System

Major Divisions

Central (CNS) – the brain and spinal cord

Peripheral (PNS) – the nerves connecting muscles and organs to the CNS

Nerves

What do we know about the Peripheral Nervous System?

3 kinds of neurons•sensory – sensory receptors•motor – connected to muscles and organs•interneurons – connection within the CNS

Sympathetic Parasympathetic

Peripheral Nervous System

What do we know about the Peripheral Nervous System?

AutonomicSomatic

How many cranial nerves?

How many spinal nerves?

12 pairs

32 pairs

Muscle

MotorNeuron Interneuron

Skin receptors

SensoryNeuron

Brain

What do we know about the Somatic Nervous System?

Controls both spinal cord

Nerves to and from

voluntary muscle & reflex movements

Simplest reflex

Reflex arc

What do we know about the Autonomic Nervous

System?Two divisionsSympathetic Parasympathetic

Controls Involuntary functions

Pupils dilate EYES Pupils contract

Decreases SALVATION Increases

Perspires SKIN Dries

Increases RESPERATION Decreases

Accelerates HEART Slows

Inhibits DIGESTION Activates

Secrete stresshormones

ADRENALGLANDS

Decrease secretionof stress hormones

SpinalCord

Brain

What do we know about the Central Nervous System?

Brain has Hemispheres

LeftHemisphere

Corpus CallosumRight

Hemisphere

What do we know about the Brain?

2

Each Hemisphere is divided into 4

lobes

Frontal

Parietal

Occipital

Temporal

Sensory Information sent to hemisphere

Left visualfield

Right visualfield

Opticnerves

CorpusCallosu

m

Left VisualCortex

Right VisualCortex

What do we know about Contralateral organization?

opposite

Somatosensory CortexMotor Cortex

Right Hemisphere controls of body

Movement controlled byMotor cortex

left side

Frontal

Parietal

Occipital

Temporal

What do we know about Localization of function?

Frontal

Parietal

Occipital

Temporal

Motor, speech

Somatosensory cortex

hearing, memory

balance, vision

Corpus Callosum

What do we know about Corpus Callosum?

Major (but not only) pathway between left & right

hemispheres

AidsOf left and right sides of body

motor coordination

Data received on one side can be processed in both hemispheres

What do we know about Nervous system damage?

Can occur due to: Genetics (inherited) illness (viral or bacterial), congenital (birth defect), or injury

Can affect: Central nervous system and/or peripheral nervous system

ALS causes progressive destruction of anterior horn motor neurons of the spinal column

Leads to paralysis and death

Genetic

HD causes progressive degeneration of brain cells (neurons) in certain areas of the brain

Leads to loss of motor control and intellectual faculties, emotional disturbances, and death

Polio means gray matterThe polio virus causes

inflammation of the gray matter in the anterior horn motor neurons.

These neurons innervate muscles

Symptoms: causes muscle paralysis

Poliomyelitis

Illness

SyphilisNeurosyphilis can occur

when syphilis infection goes untreated

Areas of the brain can be damaged

Symptoms: behavioral changes, mood swings, and progressive confusion

Congenital

Results when the vertebrae form incompletely

The spinal cord can be exposed or incompletely formed

Symptoms: complete loss of function from point of defect

Spina bifida AnencephalyResults when the

cerebrum fails to develop

Symptoms: unable to hear, see, or process sensory input

How might damage to the peripheral nervous system present itself?

Injury

How might damage to the central nervous

system present itself?

Which system is affected?

Positive babinski

Unable to speak

Can’t shrug left shoulder

Loss of bladder control

Loss of memoryInability to move left leg

Inability to feel heat

PNS

CNS

CNSPNS

PNS

PNS

CNS