Download The nervous system

THE NERVOUS SYSTEM
2. THE NEURON
THE PERIPHERAL NERVOUS SYSTEM
4. THE CENTRAL NERVOUS SYSTEM
1.
3.
 THIS
SYSTEM HELPS COORDINATE ALL THE
BODIES ACTIVITIES SO THEY WORK IN
HARMONY
 IT RECEIVES, PROCESSES, STORES, AND
TRANSMITS INFORMATION FROM BOTH INSIDE
AND OUTSIDE THE BODY
 CENTRAL SYSTEM:
- BRAIN
- SPINAL CORD
 PERIPHERAL SYSTEM:
- NERVES
- SENSORY RECEPTORS
 100
BILLION NEURONS (ON AVERAGE)
 ALSO CALLED “NERVE CELLS”
 IT IS A SPECIALIZED NERVE CELL IN THE
NERVOUS SYSTEM THAT RECEIVES AND
TRANSMITS MESSAGES
 MADE UP OF 4 PARTS
- DENDRITES
- CELL BODY (which contains the nucleus)
- AXON
- AXON TERMINALS
 ROLE
1.
2.
3.
OF NEURONS:
TO PICK UP STIMULI
TRANSFORM THEM INTO NERVE IMPULSES
TRANSMIT THESE IMPULSES
 STIMULUS: anything that can be perceived by a living
organism and that can trigger a reaction. Sound, light,
heat, electrical shocks, odours, hormones are all examples
of stimuli.
 NERVE
IMPULSE: an electrical signal transmitted by a
neuron
 SYNAPSE: the transition zone between two neurons that
allows a nerve impulse to be transmitted
 NERVE: a structure that helps transmit information
between the central nervous system and various regions of
the body
1.
2.
3.
4.
5.
 CHARACTERISTICS
CAN BE STIMULATED: IT REACTS TO A STIMULUS BY CHANGING INTO
AN ELECTRICAL SIGNAL (NERVE IMPULSE)
CONDUCTIVE. TRANSMITS NERVE IMPULSE FROM NEURON TO ANOTHER
UNTIL IT REACHES TARGET
CONSUMES A GREAT DEAL OF OXYGEN AND GLUCOSE. CAN ONLY
SURVIVE A FEW MINUTES WITHOUT OXYGEN
CAN LIVE MORE THAN 100 YEARS. PEOPLE KEEP THE SAME NEURONS
THEIR ENTIRE LIFE
CANNOT REPRODUCE ITSELF, CANNOT BE REPLACED IF DESTROYED
 TRANSMISSION
1.
2.
3.
OF NERVE IMPULSES
DENDRITES OF A NEURON RECEIVE MESSAGES OR STIMULI AND
TRANSFORM THEM INTO NERVE IMPULSES
THE NERVE IMPULSES ARE THEN TRANSMITTED ALONG AXONS TO THE
AXON TERMINALS
NERVE IMPULSES TRAVEL FROM ONE NEURON TO ANOTHER VIA
NEUROTRANSMITTERS SECRETED BY AXON TERMINALS ACROSS A
NARROW SPACE OR TRANSMISSION ZONE (SYNAPSE), BETWEEN TWO
NEURONS.




CONNECTS DIFFERENT PARTS OF THE BODY TO THE CENTRAL
NERVOUS SYSTEM
INTERNAL/EXTERNAL MESSAGES
SENSORY RECEPTORS: PICK UP STIMULI AND TRANSFORMS THEM
INTO NERVE IMPULSES
2 TYPES OF NERVES: sensory and motor
SENSORY NERVES: (5 SENSES + OTHERS)
-
TRANSMIT INFORMATION, THE FORM OF NERVE IMPULSES FROM
THE SENSORY RECEPTORS TO THE CENTRAL NERVOUS SYSTEM
MOTOR NERVES:(MUSCLES + OTHERS)
-
TRANMSIT IMPULSES FROM THE CENTRAL NERVOUS SYSTEM TO
THE MUSCLES IN ORDER TO PRODUCE VOLUNTARY AND
INVOLUNTARY MOVEMENTS
 BRAIN: composed of the parts of the central nervous system
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-
located in the cranium
CEREBRUM
CEREBELLUM
BRAIN STEM
 SPINAL CORD: the nervous system organ that
carries information from/to the various parts of the
body to/from the brain. It is also the reflex center
- SPINAL NERVES
- VERTABRAE

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
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COMMAND CENTER FOR ALL
VOLUNTARY MOVEMENTS
INTERPRETATION OF THE SENSES
INTELLIGENCE
CENTER FOR EMOTIONS
DIVIDED INTO TWO HEMISPHERES (RIGHT / LEFT)
RIGHT: CONTROLS THE LEFT SIDE OF THE BODY
LEFT: CONTROLS THE RIGHT SIDE OF THE BODY
OUTER LAYER – CEREBRAL CORTEX (GREY MATTER)
- Muscle control, sensory perception, memory, speech
 INNER LAYER – WHITE MATTER
- System connectedness

FUNCTION
DESCRIPTION
EXAMPLE
CONTROLS VOLUNTARY
MOVEMENTS
MOTOR CONTROL SENDS
OUT NERVE IMPULSE TO
STIMULATE MUSCLES TO
CONTRACT
-
Stretching
Muscle use
Walking
Grasping
INTERPRETS MESSAGES
PICKED UP BY SENSES
WHEN SENSES DETECT
EXTERNAL STIMULUS THIS
REGION INTERPRETS
IMPULSE AND REACTS
-
Tactile reaction
Smelling
Reaction to light
CONTROLS INTELLIGENCE
PROBLEM SOLVING,
READING, REASONING:ANY
ACTIVITY ASSOCIATED WITH
INTELLIGENCE
-
Thinking
Reflection
Reasoning
CONTROLS EMOTIONS
MANAGES EMOTIONS JOY,
SAD, FEAR, ANGER, ETC
-
Laughing
Crying
REGULATES
PHYSIOLOGICAL
FUNCTIONS
HYPOTHALAMUS IS
RESPONSIBLE FOR HUNGER,
THIRST, ALERTNESS AND
TEMPERATURE
REGULATION. ALSO
CONTROLS THE PITUITARY
GLAND
-
hot/cold
Consciousness
Sweating
 THE
CENTER FOR BALANCE AND MOVEMENT
COORDINATION
EXAMPLES:
 POSTURE
 DANCE, RUN
 MOTION SICKNESS, VERTIGO
 SPEAK
 DEXTERITY (PLAY PIANO)
 THE
CONTROL CENTER OF INTERNAL STIMULI
AS WELL AS INVOLUNTARY MOVEMENT
EXAMPLES:
 INTERNAL MUSCLES (DIGESTIVE SYSTEM)
 TWITCHING
 SPASMS
 RESPIRATION
 BLINKING
 NERVOUS
SYSTEM ORGAN THAT CARRIES
INFORMATION FROM THE VARIOUS PARTS OF
THE BODY TO THE BRAIN (AND VISE VERSA).
 THE REFLEX CENTER
 PROTECTED BY VERTEBRAE (BACK BONE)
 REFLEX: A RAPID AND INVOLUNTARY RECTION
TO A STIMULUS (GOOSE BUMPS)
 REFLEX ARC: PATH TAKEN BY A NERVE
IMPULSE DURING A RELFEX