Transcript Nervous-System

Nervous System: Functions
Sensory
Senses internal and external changes
Integrative
Analyzes sensory information
Stores information
Decides what to do with
information
Motor
Responds to Stimuli
Involuntary Control
Voluntary
Control
Composed of two divisions
1. Sympathetic
2. Parasympathetic
Controls
Heart, GI Tract, Glands,
Hormones, Respiration
Controls
Peripheral
Nervous System
Skeletal Muscles
Autonomic vs. Somatic
Two (2) – Neuron Pathway
One (1) – Neuron Pathway
Neuron extends from CNS
Neuron extends to effector organs
Antagonists
“Fight or Flight”
“Rest and Digest”
•Exercise
Digestion
•Emergency
Defecation
•Excitement
Diuresis (Urination)
•Embarrassment
The effects produced upon stimulation
of the sympathetic division of the
autonomic nervous system
Facilitated by the release of large
amounts of catecholamine (epinephrine)
from the adrenal medullae (superior
portion of kidney)
Fight or Flight
SCARED??????
Noticeable Effects
Pupils Dilate
Mouth Goes Dry
Neck & Shoulder Muscles Tense
Heart Beat Increases
Muscles acquire action
potential
Hidden Effects
Brain Stimulates
Action Potential
Blood Pressure
Increases
Adrenaline released
by Adrenal Glands
Glycogen broken down to
glucose and released into
blood for immediate
energy source
Blood Vessels Dilate
Digestion Ceases
Respiratory Rates Increase
Possible Hyperventilation
Sweating
Oxygen Debt = Muscles
demand for more oxygen
Sphincters Tighten
Cortisol released
depresses the immune
system
Everyday Responses
• Music
– Jazz = Parasympathetic
– Rap & Rock = Sympathetic
• Television
– Anger = Sympathetic
– Sports & Excitement = Sympathetic
• Screaming/Arguing = Sympathetic
• Excitement
– Bell Rings for end of school = Sympathetic
• Colors
– Light Colors = Parasympathetic
– Dark Colors = Sympathetic
Can You Think of
Any Other Responses?
Males
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Women
Stress response
“Tend and Befriend”
– Social Withdrawal
–
Social Support
– Substance Abuse
• Emotions
– Aggression
• Sympathy
Mortality
–
Aggression
– Believed responses to
• Protective responses
stress contribute to early
towards offspring and
mortality when compared to
affiliate with together
women
for shared emotional
responses to threat
•Disruption of Sexual Response
•Digestive System Disorders
Mental Disorders
~ Post-Traumatic Stress
~ Anorexia & Bulimia
~ Diarrhea
~ Constipation
~ Vomiting
•Chronic Stress = Suppression of Immune System
Cardiac Arrest
Aneurysm
Migraine Headaches
• Functional Properties
– Irritability
• Respond to stimulus and convert
to a nerve impulse
– Conductivity
• Transmits nerve impulse to other
neuron, muscle, or gland
• Occurs at synapses where
neurotransmitters diffuse and
bind chemoreceptors
• Ability to be Altered, Controlled,
or Destroyed
– Nerve impulses can be blocked and
cause membrane to become
impermeable to diffusing sodium ions
• Cold
• Pressure
• Sedatives & Anesthetics
• Limbs falling “asleep” then influx
of “pins and needles feeling”
Neurons
Dendrites - Neurological Receiver
Neuron Structure
Axons - Neurological messenger
3 main parts
1. Dendrites
2. Cell Body
3. Axon
Progressive Develop from Infancy
to Adulthood
Helps
1.Protect
2.Insulate
3. Increase Speed of Impulse
Neurolemmocytes – PNS
Oligodendrocytes-CNS
Pipe Cleaner Neuron
• 1. Take one pipe cleaner and roll it into a ball. This is will be the cell
body.
• 2.Take another pipe cleaner and attach it to the new "cell body" by
pushing it through the ball so there are two halves sticking out. Take
the two halves and twist them together into a single extension. This
will be the axon.
• 3.Take other pipe cleaners and push them through the "cell body"
on the side opposite the axon. These are dendrites. These can be
shorter than your axon and you can twist more pipe cleaners to
make more dendrites.
• 4.Wrap small individual pipe cleaners along the length of the axon.
These will represent the myelin sheath.
• 5. Wrap another pipe cleaner on the end of the axon. This will be the
synaptic terminal.
~Propagation along unmyelinated fibers
Functional Classification of Neurons
• Sensory (Afferent) neurons
– Carry impulses from the sensory receptors
• Cutaneous sense organs
• Proprioceptors – detect stretch or tension
• Motor (Efferent) neurons
– Carry impulses from the CNS to the effectors
• Interneurons (Association Neurons)
– Found in neural pathways in the central nervous
system
– Connect sensory and motor neurons
Receptor  Sensory Neuron  Interneuron  Motor Neuron  Effector
~~ Rapid, predicted, involuntary response to a stimuli
Autonomic vs. Somatic
Autonomic – Regulate activity of Smooth & Cardiac Muscle, and Glands
Somatic – Stimulate Skeletal Muscle
Reflexes
Somatic vs. Autonomic
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Pupillary
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Salivary
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Patellar
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Hand on hot stove 
Sudoriferous Glands 
Peristalsis 
Autonomic
Autonomic
Somatic
Somatic
Autonomic
Autonomic
1. Faster Communication
2. Synchronize (Heart)
3. Two-Way Transmission
Synapses
Neurotransmitters
• Endorphins
– Inhibit pain impulse
• Acetylcholine
– Muscular Contraction, R.E.M Sleep
• Dopamine
– Emotional responses
• Serotonin
– Muscle Relaxor, Induces sleep
– Hyposecretion = Depression (Prozac)
• Melatonin
– Regulates Circadian Rhythm
• Epinephrine
– Vasodilator
• Norepinephrine
– Arousal, Dreaming, Mood
Nervous Tissue : Supporting Cells
“Neuroglia”
• Astrocytes
– Maintains K+ Balance for Nerve Impulse Propagation
– Brain Development
– Helps Form Blood-Brain Barrier
• Microglia
– Phagocytes of the brain
• Ependymal Cells
– Forms Cerebrospinal Fluid
– Helps circulate cerebrospinal fluid and forms
protective cushion around CNS
• Oligodendrocytes (CNS)
– Form Myelin sheaths
Protective Coverings
Meninges “P.A.D.” the Brain
Cerebrospinal Fluid
• Produced by the Choroid Plexus
• Circulates Through Subarachnoid Space
• Clear, Colorless – Contains Glucose, Lactic Acid, Proteins, Urea,
Anions(- ions), Cations (+ ions), WBC
• Major Function
– Mechanical Protection
•Shock Absorber
•Allows Brain to “Float”
– Chemical Protection
•Regulates ionic balance responsible for neuron signaling
– Circulation
•Nutrient/Waste Exchange Between Cardiovascular and
Nervous Systems
Circulation
Choroid Plexus
Arachnoid Villus
Brain Blood Supply
Less Permeable
Easy Passage – Glucose, O2, CO2, Water, Caffeine,
Nicotine, Narcotics, and Anasthetics
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Frontal
– Primary Motor Area
– Concerned with reasoning, planning, parts of speech (Broca’s Area), movement (motor
cortex), emotions, language comprehension and problem-solving , learned skills
Parietal
– Contains Somatic Sensory Area
– Concerned with perception of stimuli related to touch, pressure, temperature , and pain.
Occipital
– Concerned with many aspects of vision
Temporal
– Concerned with perception and recognition of auditory stimuli (hearing), Olfactory (Smell),
and memory (hippocampus).
Which Fissures/Sulci Separate Lobes of the Brain?
Corpus Callosum
White Matter
Myelinated fibers, Carry impulses to and from Cerebral Cortex
110,000 Miles
Cerebral Separations
Longitudinal Fissure
Central Sulcus
Lateral Cerebral Sulcus
Parieto-Occipital Sulcus
Transverse Fissure
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Interpret/Store
Sensations
Learned , sequential
Movements
Broca’s Area
(Motor Speech)
Wernicke’s Area
(Sensory Speech)
Past vs. Present
Postcentral Gyrus
Postcentral
Precentral
Paleomammalian Brain – Primitive
– Regulates Survival Emotions
• Fear / Anger
• Sex
• Pain/Pleasure
• Memory
• Hunger
Memory Video
Thalamus
“Relay Center”
Limbic Structures
Amygdala - almond shaped mass of nuclei involved in emotional responses, hormonal
secretions, and memory. Responsible for determining what memories are stored
and where the memories are stored in the brain. It is thought that this
determination is based on how huge an emotional response an event invokes
Cingulate Gyrus - a fold in the brain involved with sensory input concerning emotions
and the regulation of aggressive behavior.
Fornix - an arching, fibrous band of nerve fibers that connect the hippocampus to the
hypothalamus.
Hippocampus - a tiny nub that acts as a memory indexer -- sending memories out to
the appropriate part of the cerebral hemisphere for long-term storage and
retrieving them when necessary.
Hypothalamus - about the size of a pearl, this structure directs a multitude of
important functions. It wakes you up in the morning, and gets the adrenaline
flowing. The hypothalamus is also an important emotional center, controlling the
molecules that make you feel exhilarated, angry, or unhappy.
Electroencephalogram (EEG)
Relaxed, Calm, Meditation
Awake, Normal Consciousness
Emotional Stress, Disorders
Sleep
Why get an EEG?
Assess Brain Function due to
- Trauma
- Infection
- Coma
Cerebellum
“Little Brain”
• Receives impulses from
proprioreceptors and eyes
• Coordination of complex
voluntary muscular
movement
• Posture and balance
Diencephalon
– Thalamus
• Relay station for nerve impulses to
Sensory Cortex
• Recognition of impulse and (Good vs.
Bad)
– Hypothalamus
• Overall Autonomic NS
• Regulates body homeostasis; metabolism,
body temperature, water balance
• Limbic System – Emotions
• Regulates the Pituitary Gland
– Pituitary Gland
• Hormone Production
– Epithalamus
• Pineal Body – Hormone Production
• Choroid Plexus – Formation of
Cerebrospinal Fluid
Brain Stem
Midbrain
- nerve pathway of the
cerebral hemispheres and
contains auditory and visual
reflex centers
Pons
- Involved in Breathing
Medulla Oblangata
- Controls heart rate, blood
pressure, breathing,
swallowing
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Diseases
Multiple Sclerosis
– Myelin sheath broken down, person loses ability to control body’s muscles
Meningitis
– Virus or bacteria infection passes into the blood stream and then into the
cerebrospinal fluid that surrounds the brain and spinal cord causes bleeding in the
brain
Cerebral Palsy
– Neuromuscular disability in which voluntary muscles are poorly controlled and
become spastic
– Most likely due to lack of oxygen during delivery
Cerebrovascular Accident (A.K.A Stroke)
– Blood circulation to the brain is blocked or a blood vessel ruptures causing
necrotic brain tissue
Parkinson’s Disease
– Persistent tremors in muscle fibers; due to deficiencies in dopamine
– Not controlled by Basal Ganglia
– Hard to initiate skeletal muscle movement
Alzheimer’s Disease
– Dementia is a brain disorder that seriously affects a person’s ability to carry out
daily activities. The most common form of dementia among older people is
Alzheimer’s disease (AD), which initially involves the parts of the brain that control
thought, memory, and language
Huntington’s Disease
– Degeneration basal nuclei
– Hard to control involuntary skeletal muscle movements
– Constant movements
Alzheimer's Eye Test
Count Every “F” in the following text:
Finished Files are The Result of Years of
Scientific Study Combined with the
Experience of Years.
How Many?
Letter from Mr. Jfreefry,
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uesdnatnrd waht I am wirtnig. The phaonmneal pweor
of the Braes mnid is fscatninag, it deosn’t mttaer in
what order the ltteers in a wrod are, the olny
iprmoatnt tihng is taht the first and lsat ltteer be in
the rghit pclae. The rset can be a taotl mses and you
can sitll raed it wouthit a porbelm. Tihs is bcuseaea
the huamnn mnid deos not raed ervey lteter by istlef,
but the wrod as a wlohe. Amzanig huh? Yaeh and I
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Go Bares!
Alzheimer's Eye Test
Count Every “F” in the following text:
Finished Files are The Result of
Years of Scientific Study Combined
with the Experience of Years.
How Many?