Download Nervous System PPT

3.01 Remember the structures of
the nervous system
Essential Question

What are the structures of the nervous system?
3.01 Remember the structures of the
nervous system
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Introduction: Structures of the
nervous system
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nervous system
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Cellular structures of the nervous
system
Neuron- a nerve cell

Extensions of the neuron

Dendrites - many

Axon - one
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Cellular structures of the nervous
system
Neuron- a nerve cell

Myelin sheath - a special
covering of the axon ( it
speeds up the impulse along
the axon)
 Produces a fatty substance
called myelin to protect
the axon

Synapse – the space between
neurons (messages go from
the axon of 1 cell to the
dendrite of another)
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Membrane Excitability
Nerves carry impulses by creating electric
charges
 Neurons have a membranes that separate its
cytoplasm inside from extracellular fluids
outside
 Neuron has a lot of K+ but little Na+;
opposite of extracellular fluid; membrane
allows for these ions to move in and out of
the cell
3.01 Remember the structures of the

nervous system
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Membrane Potential



Resting: More positive ions (K+ has moved
outside the cytoplasm) on the outside of the
membrane (ready for action)
Depolarization: A stimulus is initiated (i.e. sound)
that converts to electrical charge which allows the
“gated” Na+ ions to come into the cytoplasm
(action potential)
Repolarization: the neuron closes to allow no
more Na+ but opens the K+ gates to allow it to
escape thus sending it back to a positive outside
and a negative inside
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Structures of the nervous system

Central nervous
system

Brain- cerebral cortex
(outer) highest center
of reasoning &
intellect

Spinal cord
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nervous system
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Structures of the nervous system

Peripheral nervous
system


Nerves

Cranial nerves

Spinal nerves
Sensory receptors
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Structures of the
central nervous system:
BRAIN
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nervous system
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Structures of the
central nervous system: BRAIN

Cerebrum: largest part of the brain

Divided into two hemispheres (right and left) by a
deep groove called the longitudinal fissure
Frontal lobe
 Occipital lobe
 Parietal lobe
 Temporal lobe

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Frontal Lobe & Temporal Lobe

Frontal

Controls voluntary muscle movement
Controls speech in the left hemisphere (Broca)
Cells in R hemisphere control movements on L
side of the body and vice-versa


 Temporal


Anterior portion is smell and the rest is hearing
Wernicke area: central language area for speech
understanding & comprehension
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Parietal & Occipital Lobes

Parietal
Behind the frontal lobe and it is your sensory
center
 Where you feel pain, touch, heat, cold, and
balance


Occipital

Over the cerebellum, visual area that controls
eyesight
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Structures of the
central nervous system: BRAIN

Diencephalon
Located between the
cerebrum and the
midbrain
 Structures





Thalamus
Hypothalamus
Pineal body
Pituitary gland
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Structures of the
central nervous system: BRAIN

Diencephalon


Pineal Body- produces melatonin
below the 3rd ventricle
Pituitary Gland-size of a grape,
base of brain at the depression of
the sphenoid bone; connected to
hypothalamus; hormones of
pituitary are controlled by
hypothalamus
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nervous system
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Structures of the
central nervous system: BRAIN

Diencephalon
Thalamus – spherical mass of gray
matter; deep in the cerebral
hemispheres; relay station for
incoming & outgoing nerve
impulses
 Hypothalamus – lies below the
thalamus; part of the limbic system;
the “brain” of the Brain




Autonomic Nervous Control
Cardiovascular (BP, constriction &
dilation of vessels and heart beat)
Sleep control
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Hypothalamus continued







Temperature maintains 98.6
Appetite control- gives you signals when
you are hungry & when to stop eating
Water balance-high osmotic pressure in
blood signals water deficiency & ADH is
secreted
Manufacture oxytocin-contracts uterus in
labor
GI control- increases peristalsis
Emotional State- fear & pleasure
Mind over body experiences- when patients
given terminal diagnosis but are able to will
themselves well
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Structures of the
central nervous system: BRAIN

Limbic system
Located in the center
of the brain
 Encircles the top of
the brain stem.




Olfactory bulb-relates food
with emotions
Amygdala-emotional
reactor (fear, anxiety,
aggression
Hippocampus-memory &
learning
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Structures of the
central nervous system: BRAIN

Limbic system

Parahippocampus: monitors
strong emotions like rage &
fright
Fornix: pathway of nerve fibers
from hippocampus to
mammillary body
Mammillary Body: nucleus
transmits messages between
fornix & thalamus
Cingulated Gyrus: Modifies
Behavior & emotion
Septum pellucidum: connects
fornix to corpus callosum




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Structures of the
central nervous system: BRAIN

Cerebellum

Controls anything
regarding movement of
skeletal muscles
 Maintenance of
balance
 Maintenance of
muscle tone
 Coordination of
muscle movements
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Structures of the
central nervous system: BRAIN
Brain stem-has gray matter &
neurons responsible for sleep-wake
cycle; damage to certain area can
cause coma

Midbrain-location of cerebral
aqueduct assists w/ vision & hearing

Pons-2 way path for incoming and
outgoing impulses for both the
cerebrum & cerebellum; site of 4
cranial nerves & a respiratory control
center

Medulla oblongata-white matter
on outside serves as message center
between brain & spinal cord;
responsible for basic body functions as
breathing and heart beat
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
Structures of the
central nervous system: BRAIN
Meninges

Dura mater


Arachnoid


Outermost layer- Lines inside of
skull; tough fibrous material that has
an abundant amount of blood vessels
Middle layer- cobweb of fluid filled
spaces
Pia mater


Innermost layer- covers the brain
surface itself
CSF fills space between arachnoid
and pia mater (produced within the
ventricles & is our brain’s
shock absorber)
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Structures of the
central nervous system: BRAIN

Ventricles - lined cavities deep
within the brain
 filled with cerebrospinal fluid
 Choroid plexus – rich network of
blood vessels in all 4 ventricles of
the brain; aids in formation of
CSF
 Is selective in its ability to
allow certain things to pass
through (blood brain barrier)
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Brain Teasers
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What word do you see?
Read aloud
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Can you read this?
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Structures of the
central nervous system:
Spinal Cord

Surrounded by the
vertebrae, meninges, and
cerebrospinal fluid
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Spinal Cord Anatomy
Grey Matter: route sensory or
motor stimulus to interneurons
of the CNS in order to create a
response to the stimulus
through chemical synapse
activity.
White Matter: It contains nerve
fibers. Many of these nerve fibers
(axons) are surrounded by a type
of fat called myelin. The myelin
gives the white matter it's color.
Myelin acts as an insulator. It plays
an important role in the speed of
nerve signaling.
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Structures of the
peripheral nervous system:
Peripheral Nervous System


Afferent peripheral nerve system: sensory neurons that
send info from receptors in the periphery of the body to
the brain & spinal cord
Efferent peripheral Nerve System: motor neurons send
info from brain & spinal cord to muscles & glands


Somatic: impulses from CNS to skeletal muscles (voluntary)
Autonomic: impulses from CNS to smooth muscle (involuntary)
• 1. Sympathetic: “fight or flight”
• 2. Parasympathetic: “rest & digest”
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Structures of the
peripheral nervous system

I. Olfactory

II. Optic
III. Oculomotor
IV. Trochlear
V. Trigeminal
VI. Abducens
VII. Facial
VIII. Vestibulocochlear
IX. Glossopharyngeal
X. Vagus
XI. Accessory
XII. Hypoglossal










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Structures of the
PNS

Peripheral nervous system
31 pairs of spinal nerves
 Named by location in the spinal
cord (plexus: network of nerves in
spine)





Cervical Plexus (C1-C4): mvmt of shoulders &
neck
Brachial plexus (C5-8, T1): mvmt shoulder,
wrist & hands
Lumbar Plexus (T12, L1-4): mvmt of buttocks,
anterior thigh & leg
Sacral Plexus (L4-5, S1-2): motor mvmt leg
(sciatic nerve: lgst nerve in body—gluteus 3.01 Remember the structures of the
nervous system
maximus to knee)
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Structures of the
PNS

Peripheral
nervous system
12 cranial nerves
 31 pairs of nervous

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nervous system
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Structures of the
PNS

Motor system
Autonomic
nervous system
 Sympathetic
nervous system
 Parasympathetic
nervous system
 Somatic nervous
system

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nervous system
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Structures of the
PNS
Autonomic nervous system

Sympathetic
nervous system


Extends from the base
of the brain, along both
sides of the spinal
column
These nerves connect
to all internal organs

Parasympathetic
nervous system


The vagus nerve
connects the medulla
with organs of the
upper body
The pelvic nerve
emerges from the
spinal cord and
connects with the
organs of the lower
body
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Structures of the
PNS
Somatic nervous system

These nerves are
located along the
spinal cord.

Connect skeleton,
muscles and joints
to the brain.
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Structures of the
CNS & PNS
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Structures of the nervous system
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Essential question

What are the structures of the nervous system?
3.01 Remember the structures of the
nervous system
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