The Neuron Neuron: a cell that carries nerve impulses (action potential) Nerve: a bundle of nerve cells connected to each other to pass along action potentials

The Neuron Neuron: a cell that carries nerve impulses (action potential)Nerve: a bundle of nerve cells connected to each other to pass

along action potentials

Axon: transmits nerve impulses from the cell body to other neurons and muscles

Cell Body: contains the nucleus and other organelles of the neuron cell Dendrite: receives nerve impulses from other neurons and transmits them

to the cell body Myelin Sheath: fat substance that wraps around the axon, prevents the

electrical impulse from leaving the axon (neurons can cross over each other)

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signaldirection

myelin coating

Myelin Sheath

Axon coated with insulation made of myelin cells speeds signal

330 mph vs. 11 mph

Reflex Arc Sensory Neuron: send impulses

from the sense organs (skin, nose, tongue, eye & ear) to the interneurons found in the spinal cord

Interneuron: carries impulses from the sensory neurons to motor neurons

Motor neuron: transmits impulses from the brain and spinal cord to muscles and glands, to cause a response (ex. contract vs. relax, sweat, tears, saliva, mucus).

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Video ClipsSimple Reflex Arc

http://www.youtube.com/watch?v=Y5nj3ZfeYDQ

http://www.youtube.com/watch?v=wLrhYzdbbpE

Brain Pop: Neuronwww.brainpop.com

Simple Reflex Arc Action potentials (nerve impulses) can travel

trillions of routes of neurons. Many impulses require transportation to the brain in order for the action potential to be interpreted and processed (for an appropriate response).

The brain is NOT involved in a simple reflex arc. The nerve pathway consists of :stimulus sensory neuron interneuron (spinal cord) muscle neuron muscle/gland response

The brain will be informed of the stimulus, but is not involved in the reflex response.

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Electrical signal: Changes + and – charges from one end of a neuron to another.

Copyright © 2010 Ryan P. Murphy

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Electrical signal: Changes + and – charges from one end of a neuron to another.


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Chemical signal: Chemicals allow signals to go from one neuron to another by “jumping the gap (synapse)”.


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synapse

SYNAPSE: gap between one neuron’s axon and another neuron’s dendrite

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NEUROTRANSMITTER: a chemical that

diffuses across a synapse and binds to receptors on a neighboring neuron’s dendrite, causing the creation of a new action potential (impulse).

# 5 http://www.youtube.com/watch?v=haNoq8UbSyc

Dopamine NeurotransmitterAffects ability to experience pleasure &

pain (emotional response)

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Serotonin NeurotransmitterPlays a role in impulse control

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Endorphin Neurotransmitter

Reduces perception of pain (natural pain killer) and leads to feelings of euphoria

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Epinephrine Neurotransmitter

Helps body resist or avoid stress, fight or flight response (adrenaline)

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Melatonin NeurotransmitterRegulates sleep-wake cycle (circadian

rhythm)

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Brain AnatomyThe three main parts of the brain are the:

brainstem, cerebellum and cerebrum

Cerebrum

Brain Stem

Cerebellum

Left Hemisphere

Right Hemisphere

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The Amazing Story of Phineus Gage

http://www.youtube.com/watch?v=MvpIRN9D4D4

CEREBRUM

Functions:•Carries out

higher thought

processes •Divided into

4 lobes

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FRONTAL LOBE

Functions: •decision making

•planning,•problem solving

•language processing

Associated Cognitive Disorders:

•Mood changes•Inability to express

language•Loss in social interaction

PARIETAL LOBE

Functions: •Perception of sensory

information(touch, pressure,

temperature, pain)•Spatial mapping


• Alzheimer’s Disease• ADHD

• Schizophrenia

OCCIPITAL LOBE

Function: •Vision


• Schizophrenia (hallucinations)

• Autism?•Depression

TEMPORAL LOBE

Functions: • Recognition

• Perception of hearing, smelling and vision

•Understanding language• Learning and memory


• Schizophrenia• Alzheimer’s Disease

PONS (Top Part of Brain Stem)

Functions: • Regulates breathing


• Not known at this time

MEDULLA OBLONGATA (Bottom Part of Brain

Stem)

Functions: • Swallowing•Vomiting•Coughing•Sneezing


• Not known at this time

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HYPOTHALAMUS

Function:• Maintains

homeostasis (Hunger, Thirst, Body

Temperature, Sexual Activity)

Associated Cognitive Disorders: •Depression

•Bipolar disorder•Schizophrenia

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CEREBELLUM

Functions: • Balance

• Motor-learning• Reflex memory

• Posture

Associated Cognitive Disorders:• Autism

• Schizophrenia• Dyslexia

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The Nervous System Is Organized into Two Parts

I. Central Nervous System (CNS)Includes the brain neurons & spinal

chord neurons (interneurons)Processes information and

analyzes responses

II. Peripheral Nervous System (PNS)Includes motor nerves & sensory

nerves (smell, sight, touch, taste, sound)

Carries information gathered from the external environment to the CNS

cerebrum

cerebellum

spinal cord cervicalnerves

thoracicnerves

lumbarnerves

femoral nerve

sciatic nerve

tibialnerve

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Documents

The Neuron Neuron: a cell that carries nerve impulses (action potential) Nerve: a bundle of nerve cells connected to each other to pass along action potentials