Transcript The Nervous System

The Nervous System
http://www.brainpop.com/health/nervoussystem/nervo
ussystem/
The basic component of the
nervous system is a neuron.
Neuron-conducting cells
that constitute the brain,
spinal column, and nerves,
consisting of a nucleated
cell body with one or more
dendrites and a single
axon. Also called nerve
cell.
 Neurons have 3 basic parts to them
Cell Body [soma]
Axon
Dendrites
 http://www.brainpop.com/health/nervoussyste
m/neurons/
The nervous system has
two basic functions.
It gathers information
It interprets information
This information comes
from inside the body and
from the world outside
the body. The nervous
system responds to this
information as needed.
The way your body
interacts with the world
is through :
Stimulus
Response
Stimulus-something
that excites or
causes a physical
response in an
organism.
Response-A
reaction to a
specific stimulus.
The Brain
http://www.brainpop.com/heal
th/nervoussystem/brain/
The Brain
The nervous system
has two parts.
Central nervous
system
Peripheral nervous
system
The Central Nervous System
Central or CNSConsists of the
brain and spinal
cord
Brain
Spinal
Cord
Peripheral- nerves
connecting CNS to
muscles and organs
Central Nervous System
Peripheral Nervous System
The CNS processes and responds
to all of the messages coming
form the peripheral nervous
system. Normally, information is
transferred from the PNS to the
CNS and Back. However, in some
cases the PNS causes a response
without involving the CNS.
PNS
The PNS has two types of nerves:
Somatic and Autonomic nerves.
Somatic-control conscious
movement.
Autonomic-control
involuntary movements.
Autonomic System
 Two divisions:
sympathetic
Parasympatheitic
 Control involuntary functions
heartbeat
blood pressure
respiration
perspiration
digestion
 Can be influenced by thought and emotion
The brain can be divided
into 3 regions
medulla
Cerebellum
Cerebrum
Cerebrum -is the
thinking part of the
brain and it controls
your voluntary
muscles.
Cerebellum -It controls
balance, movement,
and coordination (how
your muscles work
together).
Medulla -is to control your
involuntary muscles the ones
that work automatically,
without you even thinking about
it, also sorts through the
millions of messages that the
brain and the rest of the body
send back and forth.
Peripheral Nervous System
2 kinds of
neurons
connect
CNS to the
body
sensory
motor
Brain
Spinal
Cord
Nerves
Motor - CNS to muscles and organs: a
nerve cell neuron that sends nerve
impulses from the spinal cord or
brainstem away from the central
nervous system toward a muscle or
gland
Sensory - sends nerve impulses from
the sense organs (sensory receptors)
to the CNS.
Brain
Sensory
Neuron
Skin receptors
Motor
Neuron
Interneuron
Muscle
The senses provide information about the
outside environment to the nervous
system. There are five senses:
Sight
Touch
Hearing
Taste
Smell
5 senses
The senses of sight, touch
and hearing involve
processing physical
information from the
environment.
The senses of smell and taste
involve processing chemical
information.
5 senses
Let’s look each one and
explore the nerve
responsible for helping
navigate our world.
Optic nerve
Optic nerve- the second
pair of cranial nerves
whose nerve fibers
transmit visual light
signals from the eye to
the brain.
http://www.brainpop.com/heal
th/senses/eyes/
Auditory nerve
Auditory nerve-nerve
connecting inner ear to
brain: a nerve that conveys
impulses relating to
hearing and balance from
the inner ear to the brain
Olfactory nerve
Olfactory nerve- nerves
consisting of sensory
fibers that conduct to
the brain the impulses
from the mucous
membranes of the nose.
taste
Taste buds-Oval-shaped
clusters of cells located on
the tongue and lining of
the mouth that contain
special nerve endings that
help give rise to the sense
of taste.
http://www.brainpop.com/heal
th/senses/taste/
skin
Is made up of
different layers. Let’s
look at 2 of them.
Dermis
Epidermis
Dermis
Dermis -the dense inner
layer of skin beneath the
epidermis, composed of
connective tissue, blood
and lymph vessels, sweat
glands, hair follicles, and
an elaborate sensory nerve
network.
Epidermis
Epidermis-the outer
layer of the skin
covering the exterior
body surface of
vertebrates.
Light to Dark
There are many different
skin tones. From the very
light to the very dark.
Let’s look at what causes
us to have different skin
color.
Melanin
Melanin-Insoluble naturally
occurring dark pigments found
in skin, hair, fur, and feathers.
Responsible for the color of
your skin.
Melanin protects the body by
absorbing ultraviolet radiation
from the sun.
 The End