Download The Nervous System

The Nervous System
What is regulation?
 The
control and coordination of all bodily
activities
Which two body systems are
responsible for carrying out this life
function?
 Nervous
 Endocrine
(hormones)
What are the major functions of
the Nervous System
 Regulation
 Recognize
and respond to stimuli (any
change in the environment)
 Sends messages between cells
Parts of the NERVOUS
SYSTEM
Central N.S.
Peripheral N.S.
•Consists of Nerves
and Neurons
Spinal Cord
Brain
• Allows for
communication
between the CNS and
the rest of the body
The body’s main
information
processing center.
Parts of the Brain
Cerebrum
Cerebellum
Medulla
The Brain
A. Cerebrum
B. Cerebellum
C. Brain Stem (Medulla)
Cerebrum
 Largest
 It
part of the brain.
is responsible for:
• Conscience thought
• Intelligence
• Memory
Cerebellum
 Second
 It
largest part of the brain.
is responsible for:
• Balance
• Coordinates muscle activity
Medulla
 Found
at the base of the brain
 Responsible for:
• Automatic Processes



Heart Rate
Breathing
Gastrointestinal activity
Spinal Cord
 Connects
 Carries
to the brain through the medulla.
messages to and from the brain.
 Coordinates
Reflexes
What are the two major
divisions of the nervous
system? What structures
comprise each of these
divisions?
The Nervous System
Identify These Parts of the Brain
#1
#3
#2
What is the main functional unit
of the peripheral nervous
system?
THE NEURON!!
Nodes of Ranvier
Saltatory Conduction
What is the difference between
a nerve and a neuron?
 Nerve
– a bundle of neurons.
– specialized cell that
transports impulses (messages)
 Neuron
Nerve
(many neurons)
Types of Neurons
 Sensory
Neurons
 Interneurons
 Motor
Neurons
Sensory Neurons
 Sensory
Neuron: Attached to receptors;
receive stimuli from the environment and
carry them to the CNS (central nervous
system).
• Ex.
 Five Senses
 Heat
 Pain
 Water Concentration
 Tissue Damage
Interneurons
 They
are found in the brain or spinal cord
(CNS), “BETWEEN” sensory and motor
neurons.
Motor Neurons
 Motor
Neuron: carry information from
interneurons to effectors (muscles or
glands) to produce a response
Structure of a Neuron
Dendrites- receive signals (impulses and sends
them down the neuron)
Cell Body- contains nucleus, cytoplasm, and other
organelles
Axon- carries electrical signals from cell body down
the neuron
A
B
D
C
E
Structure of a Neuron
Terminal Branches- end of the neuron, transmits signal to
the next one
Synapse- gap between adjacent neurons; site of chemical
activity
A
B
D
C
E
What is a nervous impulse?
 The
electrochemical signal transmitted
through the nervous system
How are impulses sent
throughout the nervous system?
 Electrically
and Chemically!!
Where is the signal electrical?
 Within
a neuron
Where is the signal chemical?
 At
the synapse
 (between neurons)
What is the name for the
chemicals that transmit nervous
impulses between neurons?
 Neurotransmitters!
Functions of Neurotransmitters
Video
What are some examples of
neurotransmitters? What types
of signals do they send?
Generalized Pathway of
Nervous System
 Stimulus
- change in internal or external
environment (ex. sound, light, heat, odor)
 Receptor
- specialized structures to receive
stimulus (ex. ear, nose, mouth, eyes, and
skin)

Neurons – Sensory -> Inter -> Motor (sense
change and figure out how to respond)
Chain Reaction
– specialized to produce a
response (a muscle or gland)
 Effectors
 Response
- the physical movement made
in response to the stimulus or the
secretion of a hormone from a gland.
The Nervous System
Reflex actions
Reflexes
A
REFLEX is an automatic response
to a certain stimulus (you have NO
control over it).
• Ex: Blinking
Sneezing
Coughing
Breathing
Heartbeat
Knee-jerk
Dilation of Pupil
What happens when you touch a
hot surface like an iron?
How do drugs affect the
nervous system?