The Nervous System

*Body Systems

*What is the Nervous System?

*Coordinates movements and maintains balance*Receives information about what is going on, processes the information, and forms a response.*Carries messages to and from brain and spinal cord*TWO divisions: central and peripheral

*Neurons

*The basic unit of the nervous system – a cell*Carry messages from one part of body to

another*Junctions called SYNAPSE

*Neurons

*Different types of neurons in system that perform specific roles

*Central Nervous System

*The “Control Center of the Body”

*Brain and Spinal Cord

*CNS – The Brain

*Weighs about 3 pounds – moist and spongy*Made up of about 100 BILLION neurons*Protected and cushioned by layers of membranes and fluids*3 Major Regions*Cerebrum*Cerebellum*Brain Stem

*CNS – The Brain

*CNS – The Brain

*Cerebrum*85% of brain’s weight*Specialized Regions*Deep groove separates*Frontal Lobe: voluntary

movements; emotions*Occipital Lobe: vision*Parietal Lobe: sensory

information*Temporal Lobe: hearing,

balance, and speech

*CNS – The Brain

*Cerebellum*Coordinates movements and balance*Simple movements would be impossible

*CNS – The Brain

*The Brain Stem*Midbrain: adjusting to sensory information*Pons: breathing and coordination*Medulla: automatic functions: heart rate, blood pressure, and swallowing

*CNS – The Spinal Cord

*Thick column of nerve tissue linking brain to most of nerves of peripheral system*Vertebrae surround and

protect*Surrounded by protective

membranes and bathed in fluid

*CNS - Reflexes

*REFLEX: automatic response to your environment*Think of a hot flame!

*Some reflexes controlled by spinal cord only, not brain, to enable your body to react faster protecting you from harm.

*Peripheral Nervous System

*Includes the network of nerves that link the rest of your body to your brain and spinal cord.*NERVE: bundle(s) of axons

packaged with connective tissue

*PNS – Sensory Division

*Some nerves carry info from ears, eyes, etc from your outside environment*Others carry info regarding your internal

conditions: BP, HR, etc*BOTH deliver their info to the CNS

*PNS – Motor Division

*SOMATIC NERVOUS SYSTEM: controls voluntary actions*Chewing food, skeletal muscle movements,

etc*AUTONOMIC NERVOUS SYSTEM: regulates

actions that happen automatically*Breathing, heart beat, digestion, crying

*Keeping Healthy

*Avoiding Head Injuries*CONCUSSION: swelling of the brain – bruiselike injury due to a blow to the head or rapid head movement (whiplash)*Loss of consciousness, vomiting, drowsiness, confusion, nose bleedBrandon Sutter - Hocke

yAnother Hockey Concussion

Mike Modano - He IS Alive...

"Scrambled Eggs"

*Keeping Healthy

*COMA: Prolonged period of deep unconsciousness*Sarah's Story*Sarah Speaks

*Keeping Healthy

*Avoiding Head Injuries*Helmets lower risk!*Wear seat belts!*Check water deepness*Avoid drugs and alcohol – lead to poor

decisions

*Keeping Healthy

*Avoiding Spinal Cord Injuries*Can result in PARALYSIS: loss of abilities to move and/or

feel body parts*Oklahoma vs Florida State*Jahvid Best

*Keeping Healthy

*Avoiding Nerve Injuries *Repeated movements may injure the

nerves in that area – Carpel Tunnel, Tarsal Tunnel*Symptoms: Weakness and numbness*Treatment: Splints, medications, surgery*Take breaks, maintain posture!

*Keeping Healthy

*Preventing Infections*Rare in NS because of protection of tissues*MENINGITIS: inflammation of the membranes

surrounding brain and spinal cord; viral or bacterial*Stiff neck, severe headache, high fever

*Rabies is an infection of the CNS

*Keeping Healthy

*Living with EPILEPSY*Sudden, uncontrolled nerve impulses; flood

of brain activity causing a SEIZURE*Epileptics are prone to seizures*Facial twitching, loss of awareness, and

muscle spasms may occur during seizures*Possibly caused by genetics, problems

during prenatal development, diseases, or head injuries

*Keeping Healthy

*Preventing Headaches*Most common problem*Tension headaches: physical or emotional

stress*MIGRAINE: especially severe and long-

lasting*Light and noise sensitive, nausea, blurred

vision*Proper diet, exercise, and sleep may help

prevent, but the cause is unknown*Avoid triggers