Download The Nervous System

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The nervous system and the endocrine
system regulate and control the activities of
the other body systems
The nervous system may be divided into two
parts:
◦ central nervous system (CNS): made up of the
brain and spinal cord
◦ peripheral nervous system (PNS): made up of
cranial and spinal nerves
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The Brain
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Cerebrum*
Cerebellum*
Brain Stem*
Medulla Oblongata*
Thalamus**
Hypothalamus**
Midbrain
& MORE!!
The Spinal Cord
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Brain: major portion of the central nervous
system
◦ Cerebrum
 What we think of as “The Brain”
 Largest organ of the
nervous system
 Consists of two
hemispheres: Right and Left
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Brain (cont’d)
Four Lobes
◦ Frontal-associated with reasoning, planning, emotions,
problem solving, movement
◦ Parietal-associated with movement, orientation,
recognition, perception of stimuli
◦ Occipital-associated with
visual processing
◦ Temporal-associated
with processing and
recognition of
sounds, memory, and
speech
◦ Activity-Stroop Effect
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Brain (cont’d)
◦ ventricles: spaces within the cerebrum that contain
a fluid called cerebrospinal fluid (CSF), which flows
through the space around the brain and spinal cord
◦ cerebral spinal fluid (CSF): clear, colorless fluid to
cushion the brain and spinal column from shock;
transports nutrients, and clears metabolic waste
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Brain (cont’d)
Medulla
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Controls involuntary actions
Looks like a swollen lump
Located at top of spinal cord
Inside, two large cords of nerve fibers
 One from Left hemisphere
 One from Right hemisphere
 The cords cross here
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Brain (cont’d)
Each half of the brain interacts with one half
of the body
The connections are crossed
Right brain-Left hand; Left brain-Right hand
Left side dominant for language—talking and
understanding language
Activity
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Brain (cont’d)
Cerebellum
Means “little brain”
Size of a pear
Located at the rear of cerebrum
Coordinate movements via
commands from the cerebrum
◦ Activity: Balancing Act
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Brain (cont’d)
Brain Stem
◦ Located below the cerebrum
◦ Connects the brain with the
spinal cord
◦ Sends messages from the
brain to the spinal cord
◦ Involved in cardiovascular
system control,
respiratory control,
pain sensitivity control,
alertness, awareness, and
consciousness
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Spinal cord
◦ Passes through the vertebrae extending from the medulla
oblongata to the level of the 2nd lumbar vertebra; conducts
nerve impulses to and from the brain and initiates reflex
action to sensory information without input from the brain
◦ Responsible for primitive involuntary reactions called
reflexes
◦ Pairs of Spinal Nerves:
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Cervical (8)
Thoracic (12)
Lumbar (5)
Sacral (5)
Coccygeal (1)
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The nerves outside the brain and spinal cord
Nerve: cordlike structure that carries
impulses from one part of the body to
another
Connects the Central Nervous System to the
rest of the body
◦ Consists of two parts
 Somatic
Voluntary
 Autonomic
Automatic! Involuntary
All the actions that we
choose to do:
Studying
Practicing Sports
Singing
What else?
All the actions that our
brain controls without
us knowing:
Digesting
Breathing
Regulating Body
Temperature
What else?
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Voluntary
Involuntary
12 pair of cranial nerves
31 pair of spinal nerves
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Cells of the nervous system are called
neurons
13-33 Billion Neurons in the brain alone
Parts of a Neuron
◦ Nucleus-stores genetic information
◦ Axon-string like structure that transmits impulses
to the next cell
◦ Dendrites-tree like structure that receives impulses
from the previous cell
◦ Cell Body-bulbous end that contains the nucleus
◦ Terminal Fibers-the end of the axon
◦ Myelin Sheath-insulation-like covering around axon
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A neuron has many of the same organelles
such as mitochondria, cytoplasm and a
nucleus, as other cells in the body.
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Neurotransmitters are chemicals or molecules
that help send synapses
Neurons send and
receive impulses
electrochemically
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This is called a
synapse:
syn=together,
haptein=to clasp
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Each cubic mm of
brain contains roughly a billion synapses
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Synaptic cleft—space between neurons
Axon terminal-part of neuron that sends
impulse to the next neuron
Dendrite-part of neuron that receives impulse
from the previous neuron
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Head injury
Problems with development
Damaged or dead nerve cells
Loss of blood flow to the brain
Cancer
Infection
Medical conditions of the
nervous system & how to
maintain and promote brain
health
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www.kidshealth.org
Soccer and the brain, Football and the brain,
Skateboarding and Extreme Sports
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www.stroke.org
Transient Ischemic Attack
Cerebrovascular Accident
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www.spinalcord.org
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www.cdc.gov/meningitis
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Avoid tobacco, drug, and alcohol use
Drink plenty of water
Get sleep!
Eat healthy foods
Never compromise your breathing
Wear helmets when pertinent
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6A:6-8
◦ Like other animals, human beings have body
systems for…coordination of body functions
◦ Although social behaviors are affected by both
genes and environmental factors, human beings are
still able to invent, learn, and modify a wide variety
of these behaviors
◦ Interactions among the senses, nerves, and brain
make possible the learning that enables human
beings to predict, analyze, and respond to changes
in their environment