1 Two main divisions a Central Nervous System CNS consists of brain and spinal cord b Peripheral Nervous System PNS includes nerves extending from brain and spinal cord ID: 779191
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Slide1
The Nervous System
Slide2The Nervous System
1. Two main divisions
a.
Central Nervous System
(CNS) – consists of brain and spinal cord
b.
Peripheral Nervous System
(PNS) – includes nerves extending from
brain and
spinal
cord
c. The CNS receives messages from the PNS, interprets them, and then sends out a response.
Slide3Neurons
2.
Neurons
- nerve cells that transmit messages to and from the spinal cord and
brain
a.
Sensory Neurons
– carry messages FROM body TO CNS
ex. Playing games in computer lab. When light switches to green, a sensory neuron transmits a message from your eye to your brain
Slide4Neurons
b.
Motor Neurons
– carry message TO body FROM CNS
ex. Your brain sends a signal through a motor neuron to tell your finger to click the mouse.
c
.
Interneurons
– connect neurons
Slide53. Structure and Functions of Neurons
1. Dendrites
– receive
information and transmit impulses toward cell
body
2.
Cell Body – large area which contains cell nucleus or power plant
3.
Axon
– transmit impulses away from cell body and toward
axon terminal
4. Axon Terminals – branched structures at the ends of neurons.
6
.
Myelin Sheath – insulating coat which covers the axon. This helps messages relay faster.
Slide6Neuron
Slide7The Central Nervous System
1. The
brain
a
. Helps you think, remember, reason, feel emotion,
and
coordinate muscle
movement
b
. Divided into three main parts: cerebrum, cerebellum, brain stem
Slide8The Central Nervous System
2. The Cerebrum
a
. largest, most complex part of
brain
b
. right and left sides communicate with each other to coordinate movement
. Right
controls left side and vice versa.
c. left hemisphere is for language, reasoning, and critical thinking
d
. right hemisphere is for spatial relationships
Slide9The Central Nervous System
3. Four lobes (parts) of the cerebrum
a. Frontal Lobe – controls voluntary movements and use of language
b. Parietal Lobe – sensory information, including feelings of heat, cold, pain, touch, and body position in space
c
. Occipital Lobe – Controls sense of sight
d
. Temporal – sense of hearing and smell
Slide10Lobes of the Brain
Slide11The Central Nervous System
4. The Cerebellum
a
. second largest part of brain
b
. maintains body’s posture and balance
c. coordinates complex muscle movements like serving a volleyball or playing violin
Slide12The Central Nervous System
5. The Brain Stem
a. 3 inch long stalk of nerve cells that connect the spinal cord to the rest of the brain
Slide13The Central Nervous System
b. five parts
c. Medulla Oblongata – regulates heartbeat, breathing rate
d. Pons – regulates breathing and controls muscles of eye and face.
e. Midbrain – controls pupil size and reflexive response of turning your head
f. Thalamus – relays incoming information from the eyes, ears, and pressure receptors in skin
g. Hypothalamus – regulates body temp, appetite, sleep
Slide14The Peripheral System
1. Broken into two parts
a. Autonomic Nervous System – controls involuntary functions such as digestion and heart rate
- you cannot control this; it is automatic! (autonomic
)
b
. Somatic Nervous System – voluntary responses that are
under
your control
feeling
and itch on your skin and scratching it
Slide15The Peripheral System
2. Autonomic Nervous System
a
. Broken down into two smaller networks
b. Sympathetic nervous system – kicks in when you are startled. Messages are sent that increase your heart rate. Also, blood vessels dilate to allow for greater blood flow.
-
“Fight or flight response”
-
Example… you are riding in a car and a deer jumps
out
in front of you. Think about how you feel. Your
body prepares
you to make a sudden reaction.
Slide16The Peripheral System
c. Parasympathetic nervous system – opposite of sympathetic nervous system
- slows heartbeat, relaxes blood vessels, lowers blood pressure
Slide17Problems of the Nervous System
1. Headaches – caused by muscle tension, eyestrain, sinus infection, dehydration, or food allergies
2. Head injuries
a
. concussion – a temporary loss of consciousness
b
. contusion – bruising of brain tissue that causes swelling
Slide18Problems of the Nervous System
3. Spinal Injuries
a. swelling of spinal cord tissue can result in temporary loss of nerve function
b
. if spinal cord is severed, you may become paralyzed.
Slide19Problems of the Nervous System
4. Meningitis – inflammation of the spinal and cranial meninges caused by a virus or bacteria
a. symptoms include fever, headache, light and sound sensitivity, and neck stiffness.
b. can result in death
Slide20How to care for/prevent these problems:
1. Eat a well-balanced diet, exercise regularly, get lots of sleep!
2. Wear protective devices – helmet, seat belt
3. Stay away from drugs and alcohol!!!
Slide21Slide22Slide23