1. NERVOUS SYSTEM Brain Spinal Cord PERIPHERAL NERVOUS SYSTEM
CENTRAL NERVOUS SYSTEM (CNS)
Brain
Spinal Cord
PERIPHERAL NERVOUS SYSTEM
Cranial & Spinal Nerves
Somatic
-- supplies the skeletal muscles & skin
Autonomic Nervous System (ANS)
-- supplies smooth muscles, cardiac, & glands
1. Sympathetic Nervous System
2. Parasympathetic Nervous System

2. NEURON -- structural unit of the nervous system Dendrites
-- conducts impulse towards the cell body
Axon
Cell Body
-- contains the nucleus
-- conducts impulses away
from the cell body

3. Nervous tissue contain cells called Neuroglial (glial)
-- supply nutrients
-- cleans up debris
-- assist in the production
Cerebrospinal fluid
Schwann Cell
-- type of neuroglial cell found outside
the CNS & forms the Myelin Sheath
a connective tissue that binds nerve
fibers together
Neurilemma Sheath
-- is that part of the Schwann cell that
contains the nucleus & allows for
regeneration of the nerve

4. The Myelin sheath acts as an insulator
& speeds up nerve transmission
Nodes of Ranvier
-- are bare spots where myelin is not present
to the next & further increase speed of
transmission
-- allows impulse to “jump” from one node
Synapse or Synaptic Cleft
-- junction between the
Axon of one neuron &
the Dendrite of another

5. TYPES OF NEURONS SENSORY (AFFERENT)
send impulses to the brain & spinal cord
send impulses away from the brain & spinal cord
MOTOR
(EFFERENT)
INTERNEURON
found only in the CNS & can be sensory or motor
--the more complex the required action, the
greater the number of interneurons involved

6. NEUROTRANSMITTERS -- are certain chemicals releases from the axon of
one neuron that changes the permeability of
allow Sodium into the cell
the cell membrane of the receiving neuron to
Epinephrine
Norepinephrine
produced by the Adrenal Medulla
Acetylcholine
-- released at the neuromuscular
junction
Dopamine
-- found only in the brain & helps regulate
body movement & facial expression
Others:
-- Serotonin
-- Histamine
-- GABA
-- Endorphins
-- Prostaglandin
-- Glutamate

7. SPINAL CORD -- contains 31 pairs of spinal nerves
-- consists of gray & white matter
1. It is a pathway for conducting
impulses to and from the brain
& spinal cord
2. It is an area of reflex activity
Spinal Tracts are nerve fibers in the cord
-- found in the columns of white
matter
-- Ascending Tracts -- carries
sensory impulses
-- Descending Tracts -- carries
motor impulses

8. -- Each spinal nerve is attached to the cord by
Spinal Roots
-- Each spinal nerve is attached to the cord by
2 roots or horns located in the gray matter
Ventral Root -- carries motor signals
Dorsal Root -- carries sensory signals
-- these roots are combined in the spinal
nerve as it leaves the vertebral column
making all spinal nerves Mixed Nerves
-- Areas where roots combine:
Cervical
-- serves muscles & skin of neck & diaphragm
(Phrenic Nerve)
Brachial
-- serves muscles & skin of the arms & hands
(Radial Nerve)
Lumbosacral
-- serves muscles & skin of lower abdomen,
genitalia, legs & feet (Sciatic Nerve)

9. CEREBRUM -- contains 2 hemispheres ( right & left) Corpus callosum
Parietal
lobe
Frontal
lobe
Temporal
lobe
Third
ventricle
Lateral
Fourth
Occipital
lobe
Pons
Medulla
oblongata
Midbrain
Thalamus
Hypothalamus
Cerebellum
Pituitary
Thalamus & Hypothalamus together is called the Diencephalon

10. FUNCTIONS OF THE
HYPOTHALAMUS
1. Body Temperature
2. Some emotions, such as fear & pleasure
3. Control of the Autonomic
Nervous System
Link between nervous & endocrine systems
4. Control of the Pituitary gland
5. Water balance
6. Appetite
7. Sleep
8. Center for mind over body phenomena

11. Cerebral Cortex (Cerebrum)
Gyri
--tissues of the brain are convoluted
-- area of brain responsible for consciousness
& functions in intelligence
Major Functions
1. Sensory perception
2. Voluntary control of movement
Sulci
3. Language
4. Personality Traits
5. Sophisticated mental events
a. Thinking
b. Memory
c. Decision making
d. Creativity
e. Self-consciousness

12. Lobes of the Brain Frontal Lobe -- thought association -- judgement
-- Broca center located in the left hemisphere
-- discrimination
-- control of skeletal muscles
(damage to this area causes APHASIA)
Parietal Lobe
-- sensory area for pain, touch,
& temperature
-- understanding speech & using
speech to express thoughts & feelings

13. Temporal Lobe
-- sensory area for hearing
& smelling
-- interpreting what we see,
hear, and smell
Occipital Lobe
-- responsible for vision
-- combining visual images
-- These areas when stimulated or depressed will
result in certain expected symptoms

14. BRAIN STEM Midbrain -- connects cerebellum, brain stem,
spinal cord & cerebrum
-- acts as a relay center for
sight, hearing, & feeling
Pons
-- also acts as connection for the cerebrum &
spinal cord
-- helps to regulate breathing along with the Medulla
-- reflex center concerned with head movement
in response to visual & auditory stimuli

15. Medulla Oblongata
-- is a relay center & contains
many vital functions:
1. Respiratory Center
-- regulates rate, depth, &
rhythm of respiration
-- sensitive to decreased O2, increased
CO2, & change in pH
2. Cardiac Center
-- regulates rate & force of the heart beat
3. Vasomotor Center
-- contracts or dilates blood vessels to regulate
blood pressure

16. -- also contains cough, vomiting, & swallowing centers
-- may affect hiccups
-- area where nerve fibers shift
so that right side of brain
control left side of body
& visa versa
-- Reticular Activating System (RAS)
area between the Pons & Medulla
responsible for keeping us awake

17. CEREBELLUM
-- aids in the co-ordination
of voluntary muscles
-- it integrates impulses
received from the cerebrum
(Frontal Lobe)
-- helps maintain balance by receiving
information from the inner ear
-- aids in muscle tone, so that all muscle fibers
are slightly tensed

18. CEREBROVASCULAR ACCIDENT (CVA)
-- a disorder of the blood system to the cerebrum
resulting in death of tissue
-- also called a Stroke
-- may be due to a blood clot or broken blood vessel
-- area of dead tissue is called an Infarct
ISCHEMIA
-- a deficiency of blood
to a body part
Transient Ischemic Attack
(TIA)

19. Central Nervous System is protected by:
1. Skull & vertebrae
2. Meninges
A. Dura Mater
-- thickest & toughest
layer
-- contains sinuses to
collect venous blood
B. Arachnoid membrane
-- middle web-like covering
C. Pia Mater
-- cerebrospinal fluid flows
in the web-like spaces
-- thin delicate layer that follows the contour
of the brain & spinal cord

20. Cerebrospinal Fluid
-- occupies the spaces between the middle layer
of the meninges
-- it cushions & nourishes
the brain & spinal cord
-- it is obtained from the
circulatory system
-- it is formed by the Choroid
Plexuses (capillaries in the
walls of the ventricles)
Pathway:
Lateral ventricle
Foramen of Munro
Third ventricle
Aqueduct of Sylvius
Fourth ventricle
into the subarachnoid space
around the brain & spinal cord & returned to
the circulatory system

21. CRANIAL NERVES On Old Olympus, Towering Tops, A Fin Visiting
Germany Viewed Some Hops
I. Olfactory
Smell
Sensory
II. Optic
Sight
Sensory
III. Oculomotor
Controls eye muscles
Motor
IV. Trochlear
Supplies one eye muscle
Motor
Deals with pain, touch, &
temperature of the face
Supplies muscles for chewing
Both
V. Trigeminal

22. VI. Abducen
Supplies one eye muscle
Motor
VII. Facial
Deals with facial expression
taste, salivary & lacrimal
glands
Both
VIII. Vestibulocochlear
Hearing
& balance
Sensory
Supplies tongue,
parotid gland, &
IX. Glossopharyngeal
Both
muscles for swallowing

23. X. Vagus
Supplies thoracic &
abdominal organs
and digestive glands
Both
-- when stimulated
can drop the heart rate
Supplies muscles
of neck & back
XI. Spinal Accessory
Motor
XII. Hypoglossal
Allows for tongue
movement
Motor

24. AUTONOMIC NERVOUS SYSTEM (ANS)
-- part of the Peripheral Nervous System
-- supplies smooth muscles, cardiac muscles, & glands
-- functions to maintain homeostasis and is
concerned with involuntary functions
Sympathetic
Parasympathetic
--begins in
the thoracic
region &
-- begins in the
cranial area
& in the
lower sacral area
extends to
the 2nd
lumbar
spinal
nerve

25. Function of the Sympathetic & Parasympathetic Nervous Systems
-- Sympathetic nervous system stimulates while
the Parasympathetic inhibits the activity of a given organ
-- acceleration
versus
slowing down
-- sympathetic system is involved with energy
expenditure
-- parasympathetic system is concerned with
restorative process

26. FUNCTIONS OF THE AUTONOMIC NERVOUS SYSTEM
SYMPATHETIC RESPONSE ORGAN PARASYMPATHETIC RESPONSE
Increase rate HEART Decrease rate (to normal)
Dilate BRONCHIOLES Constrict (to normal)
(Smooth muscle)
Pupils dilate IRIS Pupils constrict (to normal)
Decrease secretion SALIVARY GLANDS Increase secretion (to
normal)
Decrease peristalsis STOMACH & INTESTINES Increase peristalsis for
(Smooth muscle) normal digestion
Decrease secretion STOMACH & INTESTINES Increase secretion for
(Glands) normal digestion
Contracts to prevent INTERNAL ANAL Relaxes to permit defecation
defecation SPHINCTER
Relaxes to prevent URINARY BLADDER Contracts for normal
urination urination

27. Fight or Flight Syndrome
-- what happens to our body when under stress;
whether frightened or angry
-- increases heart rate,
respiratory rate,
& inhibits digestive
& urinary tract
dilates pupils

28. -- Most organs receive both Sympathetic &
Parasympathetic stimulation
-- Like the gas pedal and a brake on a car