Why the Nervous System Why the Nervous System Is Important?Is Important?

Gives us our sense of touch, pain, Gives us our sense of touch, pain, heat, and cold.heat, and cold.

Gives us movement.Gives us movement. The brain sends impulses to the The brain sends impulses to the

muscles to cause movementmuscles to cause movement Controls our involuntary organs Controls our involuntary organs

such as the heart, lungs, digestive such as the heart, lungs, digestive tract, and skintract, and skin

Components of the Nervous Components of the Nervous System System

●BrainBrain- - Control Control centercenter

–Spinal Cord- Highway for messages from the brain to the body.

–Medulla Oblongata- Controls heart rate, blood pressure, breathing, swallowing, and vomiting.

–Reticular Formation- Plays a role in consciousness.

Anatomy and PhysiologyAnatomy and Physiology

The Nervous System contains millions of nerve cells The Nervous System contains millions of nerve cells or neurons that respond to stimuli (such as touch, or neurons that respond to stimuli (such as touch, sound, light, and so on), conduct impulses, and sound, light, and so on), conduct impulses, and communicate with each other (and with other types of communicate with each other (and with other types of cells like muscle cells)cells like muscle cells)

A neuron is located in the cell body and extend from A neuron is located in the cell body and extend from processes called dendrites and axonsprocesses called dendrites and axons

Dendrites conduct impulses toward the cell body and Dendrites conduct impulses toward the cell body and axons conduct impulses away from the cell bodyaxons conduct impulses away from the cell body

Key TermsKey Terms Neuron-a specialized, impulse-conducting cell that is Neuron-a specialized, impulse-conducting cell that is

the functional unit of the nervous systemthe functional unit of the nervous system Nerve tissue- tissue composed of neuronsNerve tissue- tissue composed of neurons Neuroglia- a class of cells in the brain and spinal cord Neuroglia- a class of cells in the brain and spinal cord

that form a supporting strucuture for neuronsthat form a supporting strucuture for neurons Cell body- the compact area of a nerve cell that Cell body- the compact area of a nerve cell that

constitutes the nucleus surrounding cytoplasmconstitutes the nucleus surrounding cytoplasm Axon- the appendage of the neuron that transmits Axon- the appendage of the neuron that transmits

impulses away for the cell bodyimpulses away for the cell body Dentrite- the branching process of a neuron that Dentrite- the branching process of a neuron that

conducts impulses toward the cellconducts impulses toward the cell Synapse- region where nerve impulses are Synapse- region where nerve impulses are

transmittedtransmitted

Neurons and SynapsesNeurons and Synapses Neuroglial or glial cells Neuroglial or glial cells general general

functions: functions: 1 - forming myelin sheaths 1 - forming myelin sheaths

2 - protecting neurons 2 - protecting neurons 3 - regulating the internal 3 - regulating the internal environment of neuronsenvironment of neuronsin the central nervous system in the central nervous system

SynapseSynapse- point of impulse - point of impulse transmission between neuronstransmission between neurons

This impulse impulse is transmitted This impulse impulse is transmitted by the release of chemicals called by the release of chemicals called chemical transmitters chemical transmitters

Picture Picture of of SynapsSynapsee

Types of NeuronsTypes of Neurons

Multipolar neurons-Multipolar neurons-have many have many processes that extend from the cell processes that extend from the cell body: lots of dendrites plus a single body: lots of dendrites plus a single axon, they cause activity and axon, they cause activity and communicationcommunication

Unipolar neurons- Unipolar neurons- have but one have but one process from the cell body. That process from the cell body. That single, short process splits into longer single, short process splits into longer a dendrite plus an axon. Unipolar a dendrite plus an axon. Unipolar neurons are sensory neuronsneurons are sensory neurons

Bipolar neuronsBipolar neurons-- have two processes have two processes - one axon & one dendrite. These - one axon & one dendrite. These neurons are also sensory. neurons are also sensory.

Neuron Neuron CellCell

Central Nervous SystemCentral Nervous System The brain plays the main The brain plays the main

role in body functionsrole in body functions Spinal cord is connected Spinal cord is connected

to brainstemto brainstem The basic unit of the CNS The basic unit of the CNS

is the neuronis the neuron Neurons allow different Neurons allow different

parts of the body to parts of the body to communicate with each communicate with each otherother

The CNS is surrounded The CNS is surrounded by bone-skull and by bone-skull and vertebrae. Fluid and vertebrae. Fluid and tissue also insulate the tissue also insulate the brain and spinal cord.brain and spinal cord.

Peripheral Nervous SystemPeripheral Nervous System

• Nerves connect the brain and spinal cord to the Nerves connect the brain and spinal cord to the rest of the body rest of the body

• Cranial nerves in the PNS take impulses to and Cranial nerves in the PNS take impulses to and from the brainfrom the brain

• There are two major components of the PNS There are two major components of the PNS motor pathways: the somatic and the autonomic motor pathways: the somatic and the autonomic

1. sensory (afferent) pathways that provide input 1. sensory (afferent) pathways that provide input from the body into the CNSfrom the body into the CNS

2. motor (efferent) pathways that carry signals to 2. motor (efferent) pathways that carry signals to muscles and glandsmuscles and glands

Somatic Nervous SystemSomatic Nervous System

Inhibitory signals, cannot be sent through the Inhibitory signals, cannot be sent through the motor neurons of the somatic system.motor neurons of the somatic system.

Includes nerves controlling the muscular system Includes nerves controlling the muscular system and external sensory receptorsand external sensory receptors

External sense organs (including skin) are External sense organs (including skin) are receptors receptors

Motor neurons of the somatic system are different Motor neurons of the somatic system are different from those of the autonomic system.from those of the autonomic system.

Autonomic Nervous Autonomic Nervous SystemSystem

-Controls internal organs such as muscles in the heart, smooth muscle in organs, intestines, and bladder

-Regulates:

•Circulation

•Respiration

•Digestion

•Excertion

-Requires us to “fight” or take “flight” and allows us to “rest” and “digest”

-Helps adapt to changes in environment using two components PNS & SNS

The Sympathetic & The Sympathetic & Parasympathetic Nervous Parasympathetic Nervous SystemsSystems

•Active pushing function

•Located in the sympathetic chain and connects skin, blood vessels, and organs in the body cavity

•Relaxation function

•slows the heart rate, increases intestinal and gland activity

SNS

PNS

Both systems innervate the same organs and act in opposition or work in balance with each other directly or indirectly and affect almost every structure in the body

CNS disorders/diseasesCNS disorders/diseases

CNS disorders/diseases are in any component of the brainCNS disorders/diseases are in any component of the brainor the spinal cord. Some common disease/disorders are:or the spinal cord. Some common disease/disorders are: Neurogenetic diseases - Huntington’s disease and Neurogenetic diseases - Huntington’s disease and

Muscular dystrophyMuscular dystrophy Degenerative diseases of adult life - Parkinson’s and Degenerative diseases of adult life - Parkinson’s and

Alzheimer’s diseaseAlzheimer’s disease Metabolic disease - StrokeMetabolic disease - Stroke Infectious disease - AIDS Infectious disease - AIDS Trauma - Spinal cord and head injuryTrauma - Spinal cord and head injury Convulsive disorders - Epilepsy Convulsive disorders - Epilepsy Developmental disorders - Cerebral palsyDevelopmental disorders - Cerebral palsy Brain tumorsBrain tumors

Brain TumorBrain Tumor

Drug effects on the BrainDrug effects on the Brain

When you consume drugs it makes its way intoWhen you consume drugs it makes its way intothe blood stream and goes straight to your brain. the blood stream and goes straight to your brain. Whenever you feel pleasure it is your brain secreting Whenever you feel pleasure it is your brain secreting dopamine into the amygdala region of your brain. dopamine into the amygdala region of your brain. Drugs release an excess amount of dopamine which Drugs release an excess amount of dopamine which makes the pleasure more intense. When you makes the pleasure more intense. When you continue the use of drugs your brain reduces or continue the use of drugs your brain reduces or stops producing dopamine because the drugs stops producing dopamine because the drugs already produce enough. Your brain then relies on already produce enough. Your brain then relies on the drug and you become addicted. the drug and you become addicted. Drugs impair the brain making it hard for the rest of Drugs impair the brain making it hard for the rest of your body to receive messages. Some drugs your body to receive messages. Some drugs deteriorate the brain and cause long term effects.deteriorate the brain and cause long term effects.

BibliographyBibliography

www.medterms.comwww.medterms.com www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookNERV.htmlwww.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookNERV.html www.people.eku.edu/ritchisong/301notes2.htmwww.people.eku.edu/ritchisong/301notes2.htm www.photobucket.comwww.photobucket.com www.dictionary.comwww.dictionary.com www.uq.edu.auwww.uq.edu.au

By: Jasmin ZamoraBy: Jasmin Zamora Tyler WilliamsTyler Williams Derek JacksonDerek Jackson