Nervous System Receives info about internal & external environ & responds to that info Helps maintain Homeostasis Allows you to speak, smell, taste, hear, see, move, think & experience emotions

Pathway of an Impulse

2 Subdivisions Central Nervous System includes brain spinal cord Cerebrum, Cerebellum, Medulla spinal cord Peripheral Nervous System Nerves Nervous system worksheet – label diagram

Central Nervous System Brain Largest organ in this system Controls most functions of the Body

Central Nervous System Spinal Cord Thick column of nerve tissue Links brain to nerves

Brain Neurons called Interneurons Protected by Skull 3 layers of connective tissue Fluid between middle and innermost layer

Brain Has 3 Parts Brain Stem Medulla part connected to spinal cord controls involuntary body actions (breathing, heartbeat)

Brain Has 3 Parts Cerebellum 2nd largest part of brain Gives body its sense of balance Coordinates actions of muscles

Brain Has 3 Parts Cerebrum - largest part Carries out learning, remembering, and making judgments Interprets input from the senses Controls thought and voluntary movement Nervous system at work worksheet – label diagram and match functions

Cerebrum Has 2 hemispheres left for right side of body right for left side of body (axons cross over to opposite side of body in spinal cord)

hyperlink to website with more info

Central Nervous System Spinal Cord Link between Brain and Peripheral Nervous system Protected by Vertebral column, layers of connective tissue and spinal fluid

Peripheral Nervous System Network of Nerves Branch out from Central Nervous system Communication pathways that connect the CNS to the rest of the body

2 Groups of Nerves Somatic Autonomic Voluntary actions Examples Involuntary actions

2 Types of Neurons Sensory Neurons receptors that detect changes Motor Neurons Make muscles contract

The Connection Central nervous system receives info from Sensory neurons and sends info through Motor neurons

Reflex Automatic response that occurs rapidly and without conscious control Can respond before impulse reaches brain (spinal cord back to muscle) Helps protect the body

Nervous System Injuries Concussion To decrease chances of Injury Wear a helmet during activities with risk of hitting head

Nervous System Injuries Spinal cord injuries Damaged axons cannot pass impulses Results in Paralysis Most common cause? Car accidents

Senses Pages 192-200

The Affects of Drugs and Alcohol

Any chemical that causes a physical or emotional change in a person Drug Any chemical that causes a physical or emotional change in a person

The deliberate misuse of drugs for purposes other than medical Drug Abuse

Use, Misuse, or Abuse? Taking a medicine properly and in its correct dosage Improper use of a drug Intentional improper use of a drug

Tolerance The state in which a drug user needs larger and larger amounts of drugs to produce the same effect on the body

Withdrawal The period of adjustment that occurs when a person stops taking a drug

Addiction The state in which a drug user is emotionally and physically dependent on a drug The person is used to the feelings and moods produced by the drug

Signs of Misuse or Abuse Difficulty focusing eyes, glazed look Uncharacteristically passive or aggressive Decline in personal appearance Unexplained bruises or accidents Loss of memory

Signs of Misuse or Abuse Decline in school or work performance Frequent absences Damaged relationships with family members Changes in peer group or friendships

How can you Help? Seek adult or professional help Stop covering or making excuses for them Talk to and express concern for them Ask another friend to help

Kinds of Drugs Depressant Stimulant Inhalant Slows the CNS Speeds up body processes Inhalant Mood altering affects Breathed in

Kinds of Drugs Hallucinogen Steroid distorts senses See or hear things that aren’t there Steroid Synthetic chemical (hormone) Improves performance

Kinds of Drugs Alcohol depressant relaxation widens blood vessels interferes with judgment and reflexes affects coordination

Affects of Alcohol Impacts every system of the Body Through the Blood Stream

Alcoholism Disease in which a person is both physically addicted to and emotionally dependent on alcohol Requires withdrawal to give up Alcohol

How Drugs Enter the Body Swallowed Inhaled Absorbed through skin or mucus membranes Injected into a muscle or vein Absorbed into blood stream

Case Study # 3 List the 5 C’s and the questions that go with each step. Follow the example I gave you at the beginning of the semester. C C C C C

You are hanging out at a friend’s house on Friday night You are hanging out at a friend’s house on Friday night. His parents aren’t home and his older brother offers you a drink from the family bar. You have never tasted alcohol before but you have learned in Science class that it really isn’t good for you. Your friend says it is no big deal and that a little won’t hurt you. Use the 5 C’s to make a decision about what you will do.