The Nervous System

By:Muhammad Butt, Colin Ciszewski, SharlynnParikh,JustineTumacder

TypesTypes

Central Nervous System (CNS) Peripheral Nervous System (PNS)

DiagramDiagram

Types of NeuronsTypes of Neurons

• Sensory neuron - nerve cells that carries impulses from a sense receptor to the brain or spinal cord.

• Relay neuron- The nerve cell that connects sensory and motor neurons

• Motor neuron- The nerve cell that transmits impulses from the brain or spinal cord to a muscle or gland

Neuron video https://www.youtube.com/watch?v=JrdaEGwGu-w (start at 1:10)

Neurotransmission-https://www.youtube.com/watch?v=p5zFgT4aofA

Central Nervous System (CNS)Central Nervous System (CNS)

• Consists of brain and spinal cord• Major parts of the brain are:

• Forebrain• Midbrain • hindbrain

• Forebrain – contains the thalamus and hypothalamus, as well as the cerebrum, which is the largest part of brainFxns: receiving and processing sensory information, thinking, perceiving, producing and understanding language, and controlling motor function

CNS Cont.CNS Cont.

• Midbrain – with the hindbrain, they make up the brainstem. Midbrain connects the hindbrain and forebrain through the brainstem• Fxns in auditory and visual response, and motor function

• Hindbrain – extends from spinal cord. It contains the pons and cerebellum• Fxns: maintain balance, movement coordination, and involved in

senses information• Spinal cord – transmits messages from the brain to areas of

the body and vice versa. The nerves of the spinal cord are grouped into bundles, creating nerve fibers

Peripheral Nervous System (PNS)

• PNS mainly connects CNS and environmental stimuli to allow body to respond properly.

• PNS divided into 2 systems:• Somatic Nervous System: governs voluntary actions

and body reflexes• Autonomic Nervous System: regulates involuntary

actions such as breathing and digestion

Somatic Nervous System

• Controls all voluntary movements • Consists of 3 parts:

• Spinal Nerves: Peripheral nerves that carry sensory information into spinal cord and motor commands

• Cranial Nerves: Nerve fibers that carry information from and to the brainstem. The information carried are related to smell, taste, vision, eye muscles, ears, etc

• Association Nerves: integrate sensory input and motor output

Autonomic Nervous System (ANS)

• Functions as a control system, mostly below the level of consciousness

• Controls heart rate, digestion, respiratory rate, pupil dilation, perspiration, and sexual arousal

• ANS is divided into 2 systems:• Parasympathetic Nervous System• Sympathetic Nervous System

Sympathetic Nervous System

• “Fight-or-Flight” System• Main function is to prepare your body in

emergencies and helps you in stressful situations

• A person in a fight-or-flight mode may have increased blood pressure, breathing rate, and heart rate, dilated pupils, run faster, and have an adrenaline rush

Parasympathetic Nervous System

• “Rest-and-digest” System• Its major function is to keep the body in

its normal state by helping the body breath regularly, excrete hormones, and eat and digest food.

DiseasesDiseases

• Multiple Sclerosis • Huntington’s Disease• Aphasia• Amyotrophic Lateral Sclerosis (ALS)

Multiple SclerosisMultiple Sclerosis

• Chronic inflammation disease of CNS where the body’s immune system eats myelin sheath

• Myelin sheath, protective cover of nerve fibers, is lost and as a result, communication between brain, spinal cord, and rest of the body is interrupted• Damaged myelin = travelling

impulses is slowed or blocked

• Causes: viruses, environmental factors, genetic factors, autoimmune disorders

Multiple Sclerosis Cont.Multiple Sclerosis Cont.

• Symptoms: • Loss of vision• Weakness in limbs• Fatigue• Slurred speech• Electric shock sensations from certain head

movements• Treatments:

• To slow progress: Beta interferon, type of drugs that reduces number and severity of attacks

• To treat symptoms: physical therapy, muscle relaxants, and medication to reduce fatigue

• Inherited disorder affecting people mostly in their 40’s and 50’s

• Affects spinal cord and brain, where abnormal cells are found

• Huntington is formed from an abnormal gene which prevents brain cells from protecting themselves against toxic chemicals.

• This worsens when the amount of neurotransmitters in the brain decrease

Huntington’s Disease

Huntington’s Disease Cont. Huntington’s Disease Cont.

• Symptoms:• uncontrollable jerky movements• rapid eye movements• memory problems• change in mood

• Death occurs 15 – 20 yrs after first symptoms• No cure• Medicine for treating symptoms:

• Depression: Tricyclic antidepressants• Movement disorders: drugs that also treat parkinsonism

and dystonia• Antisocial behavior: drugs such as Chlorpromazine

Aphasia

• Neurological disorder due to damage on language parts of the brain from usually a stroke or brain damage

• Inability to speak and/or understand written and spoken language • Affects mostly adults and those who experienced stroke

• Causes: • usually stroke• brain injury• brain tumor• symptom of epilepsy

Aphasia Cont.

• During stroke, the most common cause, brain tissues are damaged due to lack of oxygen and blood to the brain

• Treatment:• Language therapy• Rehabilitation with speech pathologist

• Patient practices how to read, write, follow directions, and repeat what they hear

https://www.youtube.com/watch?v=1aplTvEQ6ew

Amyotrophic Lateral Sclerosis (ALS)Amyotrophic Lateral Sclerosis (ALS)

• “Lou Gehrig’s Disease”• A-myo-trophic: No muscle nourishment• Motor neurons from the brain and spinal

cord that connect to muscles are affected• Degeneration of motor neurons leads to

their death. As a result, control of muscle movement is lost

• Degenerated motor neurons cannot send impulses to muscle fibers. Therefore, muscles do not receive nourishment and begins to atrophy as a result• Effect: Paralyzed in later stages

ALS Cont.ALS Cont.

• Symptoms:–Muscle weakness in arms, legs, muscles

used in talking, breathing, swallowing–Difficulty breathing and swallowing–Muscle cramping

• Currently no cure or treatment (death usually occurs 3-5 years after diagnosis)

• Certain drugs, such as riluzole, slows ALS progression

LinksLinks

• https://www.youtube.com/watch?v=x4PPZCLnVkA- Crash course- nervous system

• http://www.livescience.com/22665-nervous-system.html

Works CitedWorks Cited

• http://biology.about.com/od/organsystems/ss/central-nervous-system.htm• https://www.boundless.com/physiology/autonomic-nervous-system-ans/introductio

n-to-autonomic-nervous-system/somatic-compared-to-autonomic-nervous-system/• https://www.boundless.com/psychology/the-brain-and-behavior/the-nervous-syste

m/the-peripheral-nervous-system-pns/• http://voices.yahoo.com/major-functions-sympathetic-parasympathetic-8876015.ht

ml?cat=4• http://www.bbc.co.uk/science/humanbody/body/factfiles/peripheralnervoussystem/

peripheral_nervous_system.shtml• http://www.mayoclinic.org/diseases-conditions/multiple-sclerosis/basics/definition/

con-20026689• http://www.netdoctor.co.uk/diseases/facts/huntingtons.htm• http://www.webmd.com/brain/aphasia-causes-symptoms-types-treatments• http://www.nhs.uk/Conditions/Aphasia/Pages/Causes.aspx• http://www.alsa.org/about-als/what-is-als.html