Download The Nervous System

Maria Buan, Melissa Jonhson,
Jane Long
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The Nervous System
 Feeling,
thinking, remembering,
moving
 Sends & receives information that
stimulates muscles and glands
 Brain, spinal cord, neurons, &
nerves
The Nervous System
SENSORY
FUNCTIONS
 Involuntary actions
 Detects changes in
the body
 Creates sensations
 Produces thoughts
and memories
MOTOR
FUNCTIONS
 Voluntary actions
 Responds to
impulse
 Muscles & glands
 Controls skeletal
muscle system
The Nervous System
 Central
Nervous
System
 Brain & spinal
cord
 Integrates
information
 “Control Center”
Retrieved from http://www.umm.edu/
graphics/images/en/19588.jpg
The Nervous System
 Peripheral
Nervous System
 Sensory & motor
neurons
throughout body
 Receptors and
effectors
Retrieved from http://www.clipart.dk.co.uk/
413/ subject/Biology/Nervous_system
Neurons
 A specialized
cell that transmits
signals throughout the body
 Cell body
 Contains dendrites
 Contains a nucleus
Retrieved from http://scientopia.org/
blogs/scicurious/2011/05/04/science-101-theneuron/
Neurons
 Dendrites
 Receives information
 Axon
 directs impulse away
 Schwann
Cells
 Cells that wrap around axon
 Produces myelin
Neurons
Dendrites
Cell Body
Axon
Nucleus
Schwann
Cell
Axon Terminal
Nucleus of
Schwann Cell
Retrieved from http://en.wikipedia.org/wiki/Neuron
Neurons
Anaxonic
Retrived from
http://iupucbio2.iupui.edu/
anatomy/images/Chapt13/FG13_10.jpg
Bipolar Unipolar Multipolar
Retrieved from http://iupucbio2.iupui.edu/
anatomy/images/Chapt13/FG13_10.jpg
Synapse
Synapse: A junction between two
neurons where an impulse from
one neuron is sent to another
 Synaptic cleft: space between
two neurons

Synapse
 Synaptic
Transmission:
Neurotransmitters cross synaptic cleft &
bind to receptors of other neuron
Retrived from http://scoehealthcoop.wikispaces.com/Neuron+and+Synapse
Synapse
 Neurons
in resting state have
negative charge
 As impulse move down axon,
negative charges become
positive, causing
action potential
Retrived from http://apbrwww5.apsu.edu/t
hompsonj/Anatomy
Synapse
 Action
Potential: a rise in the
number of positive ions in a
neuron’s membrane that allows
impulse to move down axon
 Causes impulse to move across
synaptic cleft to another neuron
Major Structures of the Brain

Cerebrum
 Diencephalon
 Brainstem
 Cerebellum
Retrieved from http://www.sharpbrains.com/
blog/2011/11/20/research-on-appliedneuroplasciticy-rewiring-the-brain-to-ease-pain/
Major Structures of the Brain

 Cerebrum
 Made up of two
hemispheres
 Contains 75%
of all neurons
 Divided into 4
lobes
Retrieved from http://www.mayoclinic.com/
health/medical/IM00317
Lobes of the Brain
Parietal Lobe
Frontal Lobe
Occipital
Lobe
Temporal
Lobe
Brain
Stem
Cerebellum
Retrieved from
http://en.wikipedia.org/wiki/File:Lobes_of_the_brain_NL.svg
Major Structures of the Brain
 Four
lobes of the brain:
 Frontal: reasoning, planning,
emotions
 Parietal: orientation, recognition
 Temporal: perception, memory,
speech
 Occipital: visual processing
Major Structures of the Brain
 Functions
of the Cerebrum
 Provides higher brain functions
 Sensory, motor, & association areas
 Dominant hemisphere functions
better in verbal actions, while
nondominant specializes in
nonverbal functions
Major Structures of the Brain
 Diencephalon
 Between the
hemispheres
 Thalamus and
hypothalamus
 Makes up the
limbic system
Retrieved from http://en.wikipedia.org/
wiki/File:Illu_diencephalon_.jpg
Major Structures of the Brain
 Functions
of the diencephalon
 Receives all sensory impulses
 Sensations
 Maintains homestasis
 Limbic system controls emotions
Major Structures of the Brain
 Brainstem
 Bundle of
nervous tissue
 Includes
midbrain, pons,
and medulla
oblongata
Retrieved from http://sccpsy101.com/home/
chapter-3/section-4/brain_stem/
Major Structures of the Brain
 Functions
of the Brainstem:
 Midbrain: eye and head movements
 Pons: sends impulses, helps
regulate breathing
 Medulla Oblongata: contains reflex
centers
Major Structures of the Brain
 Cerebellum
 Located at the
base of skull
 Made of white
matter and a
thin, outer
layer of gray
matter
Retrieved from http://neuroscience.uth
.tmc.edu/s3/chapter05.html
Major Structures of the Brain
 Functions
of the Cerebellum
 Communicates with nervous system
 Specializes in positions of body
parts and coordination of
movements
 Maintains posture
Two Nervous Systems
Central
 Brain & spinal
cord
 Processes &
interprets info
 Sends
information to
nerves
Peripheral
 Cranial &
spinal nerves
 Sends info to
muscles and
organs
 Voluntary &
involuntary
Autonomic Nervous System
 Involuntary
movements
 Controlled by PNS
 Divided into two categories
 Sympathetic
 Parasympathetic
Autonomic Nervous System
Sympathetic
 Emergency
conditions
 Leaves spinal
cord
 Secretes
norepinephrine
Parasympathetic
 Ordinary
conditions
 Begins in brain
and spinal cord
 Secretes
acetylcholine
Somatic Senses
 Receptors
in the skin, muscles &
joints
 Senses touch,
temperature,
pain, pressure
Retrieved from http://www.medicalook.com/
human_anatomy/organs/Somatic_senses.html
Somatic Senses
 Touch
and pressure receptors
-Senses mechanical forces that
disform tissues
1) Free Nerve-endings
• Common in epithelial tissues
• Free ends extend between
epithelial cells
Somatic Senses
 Touch
and pressure receptors cont.
2) Meissner’s corpuscles
• Small, flattened connective tissue
cells
• Common in hairless parts of the skin
• Responds to light touch
Somatic senses
 Touch
and pressure receptors cont.
3) Pacinian Corpuscles
• Large connective tissue fiber & cells
• Common in subcutaneous layer,
muscle, tendons & joint ligaments
• Responds to heavy pressure
Somatic Senses
 Temperature
senses
 Warm receptors
-sensitive to 77˚F(25˚C) or higher
-unresponsive at & above 113˚F
(stimulate pain receptors)
(burning sensation)
Somatic Senses
 Temperature
senses cont.
• Cold receptors
-sensitive to 50˚F(10˚C)~68˚F(20˚C)
-unresponsive below 10˚C
(stimulate pain receptors)
(freezing sensation)
Somatic Senses
 Pain
-
-
receptors
Distributed throughout the skin &
internal tissues (NOT so much in
the brain)
Once activated, it may send
impulses to the CNS.
Thus, pain may persist.
Olfactory & Taste receptors
 Chemoreceptors
: chemicals
dissolved in liquids stimulate
them
 We usually smell & taste food AT
THE SAME TIME
Olfactory Nerve
 Olfactory
receptor cells (bipolar
neurons) are stimulated by odorant
molecules & send nerve impulses.
 The fibers synapse with neurons in
the olfactory bulbs.
 Additional impulses travel along the
olfactory tracts to the limbic system.
Taste buds
 10,000
taste buds associated
with papillae
 Taste cells (gustatory
cells)=receptors
 Every taste bud has 50 ~ 150
receptors
Taste Buds
4
primary taste sensations
-sweet: like sugar
-sour: like lemon
-salty: like salt
-bitter: like caffeine
Taste Buds
 Taste
cell CAN respond to more than
one taste sensation
 Myth= one region of the tongue
responds to particular sensation
Taste Buds
 Sensory
impulses travel to the
medulla oblongata
 Ascend to the thalamus and to
the gustatory cortex (parietal
lobe)
Taste & Smell
 Odor
and taste information help
create the sensation of flavor
 Tastants (chemicals in food) and
odor molecules are similarly
picked up by the cells
Taste & Smell
 Taste
& smell together detect
flavor
 Example: sick person with a
stuffed nose cannot taste
anything; loses appetite.
Diseases & Disorders
 Huntington
Disease
 Disorder of the brain, involuntary
movements and personality
changes
 Epilepsy
 Disorder in CNS, causes seizures
and loss of consciousness
Diseases & Disorders
 Cerebral
Palsy
 Damaged cerebrum, causes
partial paralysis/lack of muscle
coordination
 Aphasia
 Loss of ability to use/understand
words due to damage in
cerebral association areas
Works Cited
"Brain Structures and Their
Functions."Serendip Studio. N.p., n.d.
Web. 27 Feb. 2013.
<http://serendip.brynmawr.edu/bb/kinser
 Cherry, Kendra. “What is a Neuron.”
About.com Physcology.
 "Anatomy of the Brain Cerebellum." Biology. N.p., n.d. Web. 27
Feb. 2013.
<http://biology.about.com/od/anatomy/p/c

Works Cited
"Central Nervous System."Biology. N.p.,
n.d. Web. 27 Feb. 2013.
<http://biology.about.com/od/organsyste
ms/ss/central-nervous-system.htm>.
 "Organization of the Nervous
System." The Peripheral Nervous
System. N.p., n.d. Web. 27 Feb. 2013.
