Nervous System By: Katelyn Jensen, Samantha Sims,

and Andrew Durham

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http://www.youtube.com/watch?v=ivk_irrH1WY

Function

• The Nervous System controls all of your body's actions and reactions. Without it you wouldn't exist!

http://zivotni-energie.cz/autonomni-nervovy-system-subtilni-energeticke

-kanaly.htmlhttp://zivotni-energie.cz/autonnervovy-system-subtilni-energeticke-kanaly.htmlomni-

Divisions

• Central Nervous System (CNS)- Nerves found in the brain and spinal cord.

• Peripheral Nervous System (PNS)- Nerves that

communicate signals to the rest of the body. It has both cranial and spinal nerves.

Anatomy of a Neuron

• Cell Body- Contains Nucleus and Organelles

• Dendrites-Cell extensions that receive information

• Axons-Transmit messages to other cells

• Myelin Sheath- Cover axons to speed up signal transfer.

Cell Body

Dendrites

Axons Myelin Sheath

Connecting Points• Synapse- The junction between two neurons, a

neuron and a muscle fiber, or a neuron and a gland.• Synaptic Terminals- extensions at the end of the

axons that release ions.• Neurotransmitters- Chemical messages released from vesicles by the synaptic terminals• Receptors- Proteins that theneurotransmitters bind to and receive signals from.

Synaptic Terminal

http://www.youtube.com/watch?v=dSkxlpNs3tU

Grouping Together

• Nerves- Bundles of Neurons. –Can be all sensory, all motor, or a mixture of

both. – Can be afferent (sending signals to the CNS) or

efferent (sending signals from the CNS)• Central Nervous System (CNS)- Nerves found in

the brain and spinal cord.• Peripheral Nervous System (PNS)- Nerves that

communicate signals to the rest of the body. It has both cranial and spinal nerves.

• Membrane Potential-Difference in electrical charge across a cell membrane.

• Resting Potential- Membrane potential when no signal is being transmitted• Formed because of higher concentration of Na+

outside the cell (positive) and higher concentration of K+ inside the cell (negative).

• Nerve Impulses (Action Potential)- Caused by a significant change in membrane potential.

What Lets it Work

Membrane Potential All or

Nothing Principle

Action Potential

Resting Potential

Action Potential Explanation

Threashold Potential (Beginning of signal-no going back)

Refratory Period

(No signals can be sent)

Responses

• A reflex is an automatic nerve circuit in response to a stimulus

• Stimuli are detected by a receptor and conveyed through a sensory neuron to an interneuron in the spinal cord.

• This then synapses with a motor neuron, causing the muscle cell to contract.

Action Potential Explanation

The Brain

The Brain

• Part of the Central Nervous System• Found in the Cranial Cavity• Helps interpret nerve signals to control the

bady's actions.

http://en.wikipedia.org/wiki/File:Meninges-en.svg

Meninges

• The membranes aroung the CNS

Cerebral Cortex- The outermost

layer of nervous tissue in the brain

Cerebrum:

Frontal Lobe Parietal Lobe

Temporal Lobe

Occipital LobeLeft

HemisphereRight

Hemisphere

http://en.wikipedia.org/wiki/Cerebrum

The highly folded outer layer of the brain. It is the largest part.

• Frontal Lobe- Site for personality and speech.• Parietal Lobe- Sensory Input

(temperature,pressure, touch, muscle control, etc). Also interprets language.

• Temporal Lobe- Center for hearing, smell, and language input.

• Occipital Lobe- Primary area for vision.

Cerebellum

http://www.intropsych.com/ch02_human_nervous_system/cerebellum.html

• Located below and behind the cerebrum• Highly Folded

• Coordinates muscle action

• Responsible for posture• Receives impulses from

muscles, tendons, joints, eyes,ears, and other brain centers.

Diencephalonhttp://upload.wikimedia.org/wikipedia/commons/5/52/Diencephalon.gif

http://commons.wikimedia.org/wiki/File:Illu_diencephalon_.jpg

Left ThalamusRight Thalamus

• Located between the cerebrum and brain

stem• Thalamus: Receives

incoming sensory signals

• Hypothalamus- Helps maintain homeostasis. Hormone production

• Both affect memory, emotion, and

motivation

Hypo

thal

amus

Brain Stem

http://www.stanford.edu/group/hopes/cgi-bin/wordpress/2010/06/the-hopes-brain-tutorial-text-version/#brainstem

• Midbrain- Visual and Auditory

Signals• Pons-

Communications between cerebral hemispheres and

cerebrum• Medulla- Control

center for heart rate, respiration

rate, etc

Spinal Cord• A column of nervous tissue • It has an outer sheath of white matter and a

rigid inner core of grey matter

http://pt851.wikidot.com/spinal-cord-injury-cell-biology

• It's purpose is to transmit signals between the brain and organs of the body

System Parts

• Cerebrospinal fluid circulates through central canal in the spinal cord and ventricles of the brain

-This gives cells nutrients while taking away waste

-It is also a cushion for the brain and spinal cord• Gray Matter consists of neuron cell bodies and

unmyelinated axons

• White matter is a set of neurons that have a white color because of myelin sheaths about axons

• Glia (aka neuroglia cells) are cells that support neurons. Three important types are:

-Astrocytes which provide support for neurons

-Oligodendrocytes which form myelin sheaths in the CNS

-Schwann cells form myelin sheaths in the PNS

Peripheral Nervous System

• The PNS consists of two main systems:1. Motor (somatic) nervous system carries

signals to skeletal muscles (voluntary system)2. Autonomic nervous system regulates the

primarily automatic and visceral functions of smooth and cardiac muscles. It is the fight or flight response (involuntary system)

Cranial Nerves

• Attach to the brain and provide sensory input and motor control; arranged symmetrically; 12 on each side of the brain

• Olfactory nerve- sensory input, carries impulses for smell to the brain

• Optic nerve- sensory input, carries impulses for vision• Oculomotor nerve- conducts motor impulses to 4 of 6

muscles of the eye• Trochlear nerve- conducts motor impulses to control

superior oblique muscle of the eyeball

Cranial Nerves cont...

• Trigeminal nerve- sensory & motor fibers, provides sensory input from face, nose, mouth, & forehead

• Abducens nerve- conducts motor impulses to the lateral rectus muscle of the eyeball

• Facial nerve- sensory & motor fibers control muscles of the face and scalp

• Vestibulocochlear nerve- sensory input for hearing and equilibrium

• Glossopharyngeal nerve- sensory and motor fibers provide general sense of taste

Cranial Nerves cont cont...• Vagus nerve- sensory and motor fibers and is

the longest of the cranial nerves.The fibers innervate platal and pharyngeal muscles and branch to the heart,lungs,stomach,and intestines.

• Accessory nerve- movement of head and shoulders

• Hypoglossal nerve- controls muscles of the tongue

http://www.merckmanuals.com/home/brain_spinal_cord_and_nerve_disorders/cranial_nerve_disorders/overview_of_the_cranial_nerves.html

Spinal Nerves • 31 pairs of nerves distributed along the length of the spinal

cord. They send impulses to the brain. • Dorsal/Sensory root- composed of afferent fibers carrying

impulses to the cord• Ventral root- contains motor fibers carrying efferent impulses

to muscles and organs • Cervical Spinal nerves- 8 pairs • Thoracic Spinal nerves- 12 pairs• Lumbar Spinal nerves- 5 pairs• Sacral Spinal nerves- 5 pairs• Coccygeal Spinal nerves- 1 pair

http://legacy.owensboro.kctcs.edu/

gcaplan/anat/notes/api%20notes%20m%20%20peripheral

%20nerves.htm

Autonomic Nervous System• Transmits signals which regulate the internal

environment by controlling smooth and cardiac muscles in the gastrointestinal, cardiovascular, excretory, and endocrine systems

• Involuntary• The divisions of it are:

-Sympathetic Division -Parasympathetic Division

Sympathetic Division• Causes the heart to beat faster and adrenaline

to be secreted when activated• "Flight or fight response"

http://www.packgraphics.com/

Parasympatic Division

• Slows the heartbeat and digestion when activated

http://www.swimmingscience.net/2010/03/stress-and-anxiety.html

Nervous System

Central Nervous System Peripheral Nervous System

BrainSpinal Cord:

Nerve bundle that communicates with

the body

Motor/Somatic Nervous System:Voluntary control

over muscles

Autonomic Nervous System:

Involuntary control over organs

Parasympathetic Division:

Rest and Digest

Sympathetic Division:

Fight or Flight

Alzheimers Disease • progressive, degenerative disease of the brain

that is characterized by loss of memory and other cognitive functions.

• Starts slow. Forgetting names, how to do simple math, and recent events.

• Later forget how to do simple daily tasks.(brushing teeth)

• Later on= anxious, aggressive, wandering from home.

• 4A's= Anger, Aggression,Anxiety,and Apathy. • No treatment. • Drugs to slow it down if caught

http://coloradodementia.org/alzheimers-disease-in-

colorado/

Encephalitis And Meningitis

• Encephalitis- inflammation of the brain. • Symptoms- fever, headache, vomiting,

photophobia, stiff neck and back, confusion, drowsiness, clumsiness, unsteady gait, and irritability.

• Meningitis- infection of the membranes that surround the brain and spinal cord.

• Symptoms- high fever, severe and persistent headache, stiff neck, nausea, and vomiting.

http://www.webmd.com/brain/

encephalitis

Epilepsy• brain disorder involving repeated

seizures of any time.• Partial(focal)-electrical disturbances are

localized to areas of the brain near the focal point of the seizure.

• Generalized(bilateral)- involves both left and right hemispheres of the brain.

• Unilateral-electrical discharge is confined to one of the two hemispheres.

• Unclassified- one that cannot be placed in one of the other three categories.

http://livingwellwithepilepsy.com/2010/07/45000-sudden-unexplained-

deaths-in.html

Multiple Sclerosis

• chronic, potentially debilitating disease that affects the brain and spinal cord.

• Inflammation of the sheath.• Genetics are linked to it. • 400,000 Americans have it between the

ages of 20 and 50.• Twice as common in woman as in men.

http://health.howstuffworks.com/diseases-conditions/musculoskeletal/multiple-

sclerosis1.htm

Parkinson's Disease

• progressive disorder caused by degeneration of nerve cells in the part of the brain that controls movement.

• Causes shortage of dopamine (neurotransmitter)• Movement impairment, tremors, slow movement (

brady kinesia), inability to move (akinesia), stooped posture. symptons worsen over time.

• 500,000 Americans have it. 50,000 new cases.• No cure. more common in men then woman

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Stroke• Cerebrovascular accident (CVA) or brain attack, is

the death of brain tissue that occurs when the brain does not get enough blood or oxygen.

• Can lead to permanent damage.• Leading cause pf death in the U.S• Can be caused by blockage of blood flow by plates

in arteries(atherodclerosis)• Symptoms: numbness/weakness on one side of the

body, confusion, trouble seeing, trouble walking / dizziness, severe headache for no know reason

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Sensory Organs • Ears, Eyes, Nose, Mouth, and Skin• Sensory Receptors- neurons that detect

stimuli. ex: mechanoreceptors, photoreceptors, chemoreceptors, etc.

• Stimulus is converted to electrical signals

http://learnhumananatomy.com/sensory-system/

Ear

• The site of hearing and equilibrium(balance)• Three distinct divisions- external, middle, and

inner• External- includes Auricle(pinna), External

Acoustic Meatus(auditory canal), and the Tympanic Membrane(eardrum)

• Middle- contains Malleus, Incus, and Stapes; is lined with mucous membrane

• Inner- contains Cochlea, Vestibule, and Semicircular Canals

http://www.betterhearing.org/hearing_loss_prevention/noise_induced_hearing_loss/

Pathology Of Ear• Meniere's Disease- abnormality of the

inner ear causing a host of symptoms, including vertigo, tinnitus, fluctuating hearing loss, and the sensation of pressure or pain in the affected ear.

• Otitis Media- inflammation or infection of any part of the outer, middle, or inner ear.

• Tinnitus- sensation of ringing or roaring sounds in one or both ears, is a symptom associated with damage to the auditory cells in the inner ear.

The Eye

• The eye facilitates sight• Orbit- contains the eyeball; cavity is lined with fatty

tissue that cushions the eye• Muscles of the Eye- six short muscles provide support

and rotary movement • Eyelids- protect eyeballs from intense light, foreign

particles, and impact• Conjunctiva- acts as protective covering and keeps the

eyelid and eyeball moist• Lacrimal Apparatus- produces, stores, and removes tears

The Eye cont...• Eyeball- organ of vision– Sclera- outer layer of the eyeball (whites of your eyes)– Cornea- transparent portion of the of the eye; bends

light rays and helps to focus them on the retina– Choroid- vascular membrane that prevents internal

reflection of light– Ciliary body- smooth muscle that governs the

convexity of the lens – Iris- colored portion of the eyeball; regulates the

amount of light admitted by the pupil – Retina- translates light waves into nerve impulses – Lens- sharpens the focus of light on the retina

Pathology Of The Eye• Cataract-clouding of the eye's lens.• Conjuctivitis(Pinkeye)-inflammation of the

conjuctiva, the tissue that lines the inside of the eyelid and helps keep the eyelid and eyeballs moist.

• Glaucoma- group of eye diseases characterized by increased intraocular pressure.

• Macular Degeneration- incurable eye disease that affects more than 10 million Americans.

http://snowbrains.com/brain-post-how-big-is-your-blind-spot/

DRUGS... don't do them

• Psychoactive Drug- drug that alters functioning of CNS. ex: caffeine

• Stimulant- drug that increases CNS activity ex: nicotine

• Depressant- decreases the activity of the CNS ex: alcohol

http://stuffnormalpeoplelike.wordpress.com/

CitationsDiscovery (2009). Retrieved from http://kids.discovery.com/tell-me/science/body-systems/your-nervous-systemLooi, S. (n.d.). Retrieved from http://www.brainhealthandpuzzles.com/diagram_of_brain.html

Holtzclaw, F. W., & Holtzclaw, F. W. (2013). Ap test prep series: Ap biology. (9th ed., pp. 243-251). San Francisco, CA: Pearson Education Inc.