Transcript The Nervous System

Chapter 7
The Human Body and the
External World
The Nervous System
• Write the WHITE
• Read the BLACK
WHAT DO YOU KNOW ABOUT THE
NERVOUS SYSTEM?
Follow along on pg. 121 of
workbook
• the nervous system :
• Receives, processes, stores and transmits
information (stimuli) from inside & outside of body
• composed of the Central Nervous System (CNS)brain and spinal cord and the Peripheral Nervous
System (PNS)- nerves
• What are the stimuli you would receive if this was
you?
The Neuron
• a specialized nerve cell
•Receive and transmit information (info.).
Use pg. 203 of textbook to fill in
the Anatomy of a Neuron on pg.
121 of workbook
Check your answers
Parts of a Neuron
Dendrites
Cell body
Nucleus
Axon
Neuron
Terminals
Neuron facts:
• transmits impulse from one neuron  to next until
reaches target (e.g. brain or muscle) Like an electric
current
• Consumes lots of O2 (only last a few minutes
without it) (why CPR is important) and glucose
• Can live for more than 100 years (keep the same
neurons your whole life-unless kill them with drugs)
• Cannot reproduce itself-not replaced if destroyed
= anything that can be perceived and then
trigger a reaction
Example: sun shining in your eyes = pupils close
• Nerve impulse = an electrical signal transmitted by
a neuron
• Synapse = transition zone between 2 neurons
(message passed to next nerve with chemicals)
Transmission of Impulses
• Dendrites = receive
messages & change
them to nerve impulses
(travel at about 430
km/h)
• Nerve impulses
transmitted along axons
to terminals
Neurotransmitter
released in synapse
Impulse transmitted
to next neuron
Nerve.mpg
Use pg. 204 of textbook to fill in
the bottom of pg. 121 in workbook
Homework: pg. 122 of workbook
Peripheral Nervous System
 the PNS =
connects CNS to
different parts of
the body
Has two types of
nerves: sensory (in)
and motor (out)
nerves
Sensory Receptors
• Pick up stimuli = change to nerve impulses
• Specialized nerve cells e.g. Retina in eye
Sensory Nerves
• Transmit information via impulses from sensory
receptors CNS e.g. Optic nerve in eye
Motor nerves
• Transmit impulses from CNS to muscles or glands
• muscles = voluntary (pick up
an object) or involuntary
(pupils
contract in bright light)
Did you know?
• Acupuncture has been practiced for 7000 years
originating in China. Channels of energy run in
regular patterns through the body. An obstruction
in the movement of these energy rivers is like a
dam that backs up the flow in one part of the body
and restricts it in others. The acupuncture needles
unblock the obstruction at the dams, and reestablish the regular flow.
Modern science explains this as:
• Needling the acupuncture points stimulates the
nervous system to release chemicals in the
muscles, spinal cord, and brain. These chemicals
will either change the experience of pain, or they
will trigger the release of other chemicals and
hormones which influence the body’s own internal
regulating system.
Kung fu panda
Use pg. 205 of textbook to fill in
pg. 123 of workbook
Homework: pg. 124 of workbook, q
1-3
The Central Nervous System
The Central Nervous System =coordinates a
major part of the nervous system
The Brain
•Composed of the parts of the CNS location in
the cranium (skull)
•A large mass of nerve cells (more than 100
billion neurons)
•There are rare exceptions!!!
Here we have a case of
“ Brainus peanutii
minimalis”
Use pg. 207 of textbook to label
the diagram on pg. 125 of the
workbook
• Brain model
The Cerebrum
•The control central of voluntary
movement, intelligence, and
sensory interpretation
•Is the center of emotion and
regulating body functions
• Outer =grey matter (cerebral cortex)= higher
brain functions (plan, reason, logic)
• inner= white matter (myelin sheath of nerves)
The Cerebellum
• control center for balance and coordination
The Brain Stem
•controls involuntary movement as
well as internal stimuli
• e.g. heartbeat, breathing, and
blood pressure.
The Spinal Cord
A nervous system organ that
sends messages to & from brain.
Processes reflexes
Fill into pg. 126 top, of workbook
meninges
•31 pairs of nerves attached to spinal cord
•spinal cord = protected by small bones
called vertebrae
• Spinal cord model
Reflex
• Rapid, involuntary reaction to a stimulus
• Involves sensory nerves, spinal cord, and motor
nerves
• Brain only receives info. AFTER
the reaction has occurred
Reflex arc
• The path taken by the nerve impulse during a
reflex
Reflex Arc
Sensory Receptor
(responds to a stimulus
by producing a impulse)
Sensory Neuron
(axon conducts
impulse)
Integrating Center
(Relay impulse from
sensory to motor neurons)
Motor Neuron
(axon conducts impulse
Effector (muscle that
to effector)
responds to a motor
nerve impulse)
Use pg. 208-212 of textbook to fill
in pg. 126 of workbook
Lab 63- Reflexes
Discuss: pg. 229 of textbook Q 1-8
Homework: pg. 127-128 of
workbook
DIGESTIVE
RESPIRATORY
WHAT IT DOES food--> nutrients oxygen (O2) in
broken down by:
CIRCULATORY
EXCRETORY
blood transports kidney- urea,
NERVOUS
receives via sensory
nutrients and O2 water, sugar
organs, processes
carbon dioxide to cells
salts out
mechanical- chew, (CO2) out
churn, peristalsis
chemical- acids,
info in brain,
and sends
transports waste skin- heat out
information back to
and CO2 from
muscles
cells
enzymes, pepsin
control centre
HOW IT LINKS
nutrients
O2 taken by
all through
kidney- blood
nerves all through
absorbed in
blood to cells
organs and
filtered in
body
small intestine
as needed to
body cells
nephron
go into blood to
burn nutrients
be taken to cells
for E
CONTROL all systems
it is the
skin- vasodilate
transportation
blood to skin
as made of cells
CO2 produced by system
needs O2 and
cells taken to
nutrients via blood
lungs by blood
Crash course Nervous system