Download The Nervous System

The Nervous System
Jacqueline Immello, Stephanie Pantano,
Shaakira Parker and Anthony Patti
What is the nervous system?
• The nervous system’s main role is controlling
and communicating. This system is where all
mental activity takes place.
• It works with the endocrine system in order
to regulate and keep homeostasis.
• Often referred to as the body’s control
center.
• The nervous system is made up of the brain, spinal
cord, and nerves that are located throughout the
body.
The Central Nervous System
The central nervous system contains the brain
and the spinal cord.
The Brain (Encephalon)
• The brain controls everything the body does
• It is the center of the nervous system
• Forebrain - Cerebrum
– Largest portion o the brain (85%)
– Controls voluntary muscle movement
– The cerebral cortex is the part of the brain
responsible for intellectual functions such as
thinking, reasoning, and storing short and long
term memory
• Midbrain
– Connects higher and lower brain functions
– Body movement
– Contains the pleasure center which has to
do with the development of addictive
behaviors
• Hindbrain
– Cerebellum
• controls balance, coordination and movement
– Brain Stem
• Connection between the brain and the spinal chord
• Controls the involuntary muscle movement like
breathing, digestion, circulation, etc.
• Also sorts messages that are sent to the brain
The Spinal Cord (Medulla Spinalis)
• The spinal chord, which is made up of
nervous tissue and support cells, runs down
the middle of the back from the brain to the
coccyx (or tailbone)
• Protected by cerebral spinal fluid and the
vertebra.
• There are 31 pairs of nerves arranged along
the spinal cord.
• The spinal cord is made up of nerve fibers
which transfer messages to parts
of the body and the brain
– Motor signals travel down the cord
– Sensory signals travel upwards
Peripheral Nervous System
• The peripheral nervous system extends out of
the central nervous system with nerves.
Neurons
• Any of the impulse-conducting cells that
constitute the brain, spinal column, and
nerves.
• Also known as nerve cells.
• Function in receiving and transmitting
signals along the aforementioned
structures.
Structure of Neurons
• Dendrites- highly branched extensions that receive
signals from other neurons.
• Axons- extensions which are much longer than
dendrites. Transmit signals to other cells. The
cells that receive these signals may be neurons or
effector cells (muscle or endocrine cells).
•
Mycelin Sheath- covers an axon for insulation of
electrical current. Consists of Schwann cells.
• Synaptic Terminals- located at branched ends of
the axon.
• Synapse- site of communication between a synaptic
terminal and another cell.
• Presynaptic and Postsynaptic neurons- The
transmitting and receiving neurons.
Neuron Structure
and
Communication
Synapse
• Neurotransmitter (a
substance contained in
the synapse) binds to
and opens gated ion
channels (labeled
receptors).
• Na+ and K+ then
diffuse through the
channel.
Neuron Function in Information Processing
• 3 stages of information processing: sensory input,
integration, and motor output.
• Sensory Input: Sensory Neurons - transmit information
from sensors that detect external stimuli and
internal conditions.
• Integration: Interneurons - integrate (analyze and
interpret) sensory input.
• Motor Output: Motor Neurons – communicate with
effector cells. Produce reflexes (automatic
responses to stimuli) in the simplest circuits.
Peripheral Nervous System
• This system is further divided into the
somatic and autonomic nervous systems.
Somatic Nervous System
• Reception of an outside influence:
- touch, hearing, sight
• Voluntary control of the body movements
through skeletal muscle
• When stimulated, the response of the nerves
is the response arc
Autonomic Nervous System
• Regulates the involuntary organs within our
body such as the heart and stomach,
muscles, and glands.
• Important in emergencies when undergoing
stress and also in regular situations like
digestion and rest.
• Can be subcategorized into the
sympathetic, parasympathetic, and
enteric nervous systems
Sympathetic Nervous System
• "Fight or Flight" responses in the face of
danger
• Blood pressure increases, your heart beats
faster, and digestion slows down.
• In the sympathetic nervous system the synapse,
ganglion uses acetylcholine as a
neurotransmitter.
• The synapse of the post-ganglionic neuron with
the target organ uses the neurotransmitter
norepinephrine.
Sympathetic
Nervous
System
Parasympathetic Nervous System
• "Rest and Digest" responses
• Blood pressure decreases, the heart beats
slower, and digestion can start
• This synapse uses the neurotransmitter
called acetylcholine.
Parasympathetic
Nervous System
Enteric Nervous System
• sends and receives impulses, records
experiences and respond to emotions.
• located in the tissue lining the esophagus,
stomach, small intestine and colon.
• the neural crest is formed in the early
stages of the embryo.
– One section turns into the central nervous
system.
– Another piece migrates to become the enteric
nervous system.
Activities
Label parts 1-3 and list their function in the nervous system
List the names
of the sections
highlighted
in red, blue,
and green
Central Nervous System Crossword
Peripheral Nervous System
Fill in the Blanks
Word Box
• cranial nerves
• voluntary
• peripheral nervous system
(PNS)
• central nervous system
(CNS)
• spinal nerves
• peristalsis
• homeostasis
• neurotransmitter
• somatic nervous system
•
•
•
•
•
•
•
•
•
enteric division
parasympathetic division
voluntary
involuntary
internal
sympathetic division
postganglionic
preganglionic
autonomic nervous system
The
1
is involved in regulating a
vertebrate’s movement and internal
environment. The PNS sends information to
and from the ____2__
. The
3
,
which starts in the brain and ends in the head
and upper body, and the
4
, which
come from the spinal cord and branch to parts
of the body below the head, are the left and
right parts of the peripheral nervous system.
They both have sensory and motor neurons.
The PNS is divided into two systems that help
to maintain 5
.
The
6
transmits signals to
and from the skeletal muscles and is
7
because it is consciously controlled by
the reflexes. The other system is the
8
. It controls smooth and cardiac
muscles, and the organs of the digestive,
cardiovascular, excretory, and endocrine
systems, which helps to regulate the
9
environment. The autonomic nervous
system has
10 control. It is divided
into three parts.
The
11
has to do with a
“flight or fight” response or the arousal and
energy generation. It performs actions such as
stimulating glucose release from the liver,
relaxing bronchi in lungs, accelerating the
heart, etc. Another division is the
12 , which is the “rest and digest”
because it causes responses of calm and a
return to self maintenance functions. This
division performs actions such as the slowing
of the heart, promoting emptying of bladder,
stimulating activities of the stomach and
intestines, etc.
Both the parasympathetic and sympathetic
divisions have
13
. They are
released by
14 and
15
neurons. Acetylcholine and norepinephrine
are two types of neurotransmitters. The last
division is called the
16
, which
consist of neurons in the digestive tract,
pancreas, and gallbladder that control the
organs’ secretions and activities in the smooth
muscles that produce
17 . This
division is regulated sympathetic and
parasympathetic divisions.
Answer Key
Brain Activity answers
1. Cerebrum – voluntary muscle movement,
thinking, reasoning, and storing short and long
term memory
2. Cerebellum -
controls balance, coordination and
movement
3. Brain Stem -
sorts messages that are sent to the brain
and controls involuntary muscle movement
Red - Forebrain
Blue - Midbrain
Green - Hindbrain
Crossword Answers
Fill in the Blank Answers
• 1. Peripheral Nervous
System
• 2. Central Nervous System
• 3. cranial nerves
• 4. spinal nerves
• 5. homeostasis
• 6. Somatic Nervous System
• 7. voluntary
• 8. Autonomic Nervous
System
•
•
•
•
•
•
•
•
•
9. internal
10. involuntary
11. sympathetic division
12. parasympathetic
13. neurotransmitters
14. preganglionic
15. postganglionic
16. enteric division
17. peristalsis
Websites
• http://faculty.washington.edu/chudler/auto.
html
• http://www.apparelyzed.com/spinalcord.html
• http://kidshealth.org/kid/htbw/brain.html#
• http://www.emc.maricopa.edu/faculty/farabee
/BIOBK/BioBookNERV.html
• http://www.innerbody.com/image/nervov.html
• http://yucky.discovery.com/flash/body/pg000
136.html
• http://www.psyking.net/id36.htm