Transcript The Nervous System - Fulton County Schools

1
The sub arachnoid space:
contains the spinal fluid
Epidural Space: out here
between the dura mater and
the bone
2
3
Spinal Cord: Gray Matter
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
Central Posterior
Horn
Canal
Anterior
Horn
4
Spinal Cord: White Matter
Posterior
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
5
What do we know about the
nervous system?
Major Divisions
Central (CNS) – the
brain and spinal cord
Peripheral (PNS) – the
nerves connecting
muscles and organs to
the CNS
Central Nervous System
Peripheral Nervous System
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
Nerves
What do we know about the
Peripheral Nervous System?
How many cranial nerves? 12 pairs
How many spinal nerves?
32 pairs
Peripheral Nervous System
Somatic
Autonomic
Sympathetic
Parasympathetic
What do we know about the
Somatic Nervous System?
Nerves to and from
spinal cord
Controls both
Sensory
voluntary muscle Neuron
& reflex movements
Simplest reflex
Reflex arc
Skin receptors
Brain
Motor
Neuro
n
Interneuron
Muscle
What do we know about the
Autonomic Nervous System?
Sympathetic Two divisions Parasympathetic
Pupils dilate
EYES
Decreases
SALVATION
Perspires
SKIN
Increases
RESPERATION
Accelerates
HEART
Inhibits
DIGESTION
Secrete stress
hormones
ADRENAL
GLANDS
Pupils contract
Increases
Dries
Decreases
Slows
Activates
Decrease secretion
of stress hormones
Controls Involuntary functions
What do we know about the
Central Nervous System?
Spinal
Cord
Brain
What do we know about
the Brain?
Right
Hemisphere
Corpus Callosum
Brain has 2 Hemispheres
Frontal
Parietal
Occipital
Temporal
Left
Hemisphere
Each Hemisphere
is divided into 4
lobes
What do we know about
Contralateral organization?
Movement controlled by
Motor cortex
Right Hemisphere controls
left side of body
Left visual
Right visual
field
field
Optic
nerves
Motor Cortex Somatosensory Cortex
Left Corpus Right
Visual Callosu Visual
Cortex
m
Cortex
Sensory Information sent
to opposite hemisphere
What do we know about
Localization of function?
Frontal
Frontal
Motor, speech
Temporal
Parietal
hearing, memory
Occipital
balance, vision
Parietal
Somatosensory cortex
Occipital
Temporal
What do we know about
Corpus Callosum?
Major (but not only) pathway
between left & right
hemispheres
Corpus Callosum
Data received on one side can
be processed in both hemispheres
Aids motor coordination
Of left and right sides of body
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
Genetic
ALS causes progressive
destruction of
anterior horn motor
neurons of the spinal
column
Leads to paralysis and
death
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
Illness
Poliomyelitis
Polio means gray matter
The polio virus causes
inflammation of the gray
matter in the anterior
horn motor neurons.
These neurons innervate
muscles
Symptoms: causes muscle
paralysis
Syphilis
Neurosyphilis can occur
when syphilis infection
goes untreated
Areas of the brain can be
damaged
Symptoms: behavioral
changes, mood swings,
and progressive confusion
Congenital
Spina bifida
Anencephaly
Results when the vertebrae
form incompletely
The spinal cord can be
exposed or incompletely
formed
Symptoms: complete loss
of function from point of
defect
Results when the
cerebrum fails to
develop
Symptoms: unable to hear,
see, or process sensory
input
Injury
How might damage to
the peripheral nervous
system present itself?
How might damage to
the central nervous
system present itself?
Which system is affected?
Positive babinski PNS
Loss of bladder control PNS
Unable to speak CNS
Can’t shrug left shoulder PNS
Loss of memory CNS
Inability to move left leg CNS
Inability to feel heat PNS