table of contents chapter preview 15.1 how the nervous system works 15.2 divisions of the nervous...
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Table of ContentsChapter Preview
15.1 How the Nervous System Works
15.2 Divisions of the Nervous System
15.3 Sight and Hearing
15.4 Smell, Taste, and Touch
15.5 Alcohol and Other Drugs
Chapter 15 Preview Questions
1. Which part of the skeletal system protects the brain?
a. spine
b. pelvis
c. skull
d. joint
Chapter 15 Preview Questions
1. Which part of the skeletal system protects the brain?
a. spine
b. pelvis
c. skull
d. joint
Chapter 15 Preview Questions
2. Which muscles can you control voluntarily?
a. heart muscles
b. leg muscles
c. diaphragm
d. stomach muscles
Chapter 15 Preview Questions
2. Which muscles can you control voluntarily?
a. heart muscles
b. leg muscles
c. diaphragm
d. stomach muscles
Chapter 15 Preview Questions
3. What is the smallest unit of any body system?
a. structure
b. organ
c. tissue
d. cell
Chapter 15 Preview Questions
3. What is the smallest unit of any body system?
a. structure
b. organ
c. tissue
d. cell
Chapter 15 Preview Questions
4. What is the eye designed to receive from the environment?
a. light rays
b. vibrations
c. lenses
d. motion
Chapter 15 Preview Questions
4. What is the eye designed to receive from the environment?
a. light rays
b. vibrations
c. lenses
d. motion
You smell a delicious aroma. You walk into the kitchen and see a bag of popcorn in the microwave. You hear some kernels still popping. Then you think to yourself, “Snack time!” Which body systems enabled you to smell, walk, see, hear, and think? How did each system play a part in your response?
How do organs and other structures enable the nervous system to function?
Section 15.1: How the Nervous
System WorksWhat are the functions of the nervous system?What is the structure of a neuron and what kinds of neurons are found in the body?How do nerve impulses travel from one neuron to another?
Jobs of the nervous system:
1. The nervous system receives information (Stimulus) about what is happening both inside and outside our bodies.
2. It directs how we react to our environment (Response)
3. It maintains homeostasis.
Kinds of NeuronsSensory Neurons: carries messages from receptors to the interneuron within the brain or spinal cord.
Interneurons: connect sensory and motor neurons. (brain and spinal chord)
Motor Neurons: sends impulses to muscles.
The Structure of a Neuron:
Cell body= with a nucleus
Dendrite = an extension that carries messages to the cell body.
Axon = carries messages away from the cell body.
How a Nerve Impulse Travels
A nerve impulse must cross the gap between the axon and the next structure this is the synapse
The axon tips release chemicals that carry
the impulse across
the gap.
Section 15.2: Divisions of the Nervous System
What are the structures and functions of the central nervous system?What are the structures and functions of the peripheral nervous system?What is a reflex?What are two ways in which the nervous system can be injured?
Divisions of the Nervous System
The Central Nervous System:
Control center of the body.
Brain and Spinal Cord
The Peripheral Nervous System:
Branches out and connects to the CNS
Somatic nerves control voluntary actions
Autonomic nerves control involuntary actions
The Brain:
100 billion neurons (all interneurons)
3 main regions
Cerebrum:
largest
Two halves
Think/remember/speak
The senses
2. Cerebellum:
Balance
Posture
Brainstem/Medulla
Controls involuntary processes
Heartbeat/blood pressure
Breathing
Divisions of the Nervous System
The Central Nervous System:
Control center of the body.
Brain and Spinal Cord
The Peripheral Nervous System:
Branches out and connects to the CNS
Somatic nerves control voluntary actions
Autonomic nerves control involuntary actions
Central Nervous System
The central nervous system is the control center of the body. It includes the brain and spinal cord.
Peripheral Nervous System
• Branches out and connects to the CNS• Somatic nerves control voluntary actions• Autonomic nerves control involuntary
actions
The Brain There are three main regions of the brain
1. Cerebrum:• largest • Two halves• Think/remember/speak• The senses
2. Cerebellum:
Balance
Posture
3. Brainstem/Medulla
Controls involuntary processes
Heartbeat/blood pressure
Breathing
Reflexes
A reflex is an automatic response that occurs very rapidly and without conscious control.
Reflexes
A reflex is an automatic response that occurs very rapidly and without conscious control.
Section 15.3: Sight and Hearing
How do your eyes enable you to see?How do you hear and maintain your sense of balance?
Vision
You eyes respond to the stimulus of light. They convert that stimulus into impulses that your brain interprets, enabling you to see.
VisionLight coming from an object enters your eye and is focused by the lens.
The light produces an upside-down image on your retina.
Receptors in your retina then send impulses to your cerebrum, which turns the image right-side up.
Hearing and Balance
Your ears are the sense organs that respond to the stimulus of sound. Ears convert the sound to nerve impulses that your brain interprets.
Sound Intensity
Sound intensity, or loudness, is measured in units called decibels. The threshold of hearing for the human ear is 0 decibels. For every 10-decibel increase, the sound intensity increases ten times. Thus, a 20-decibel sound is ten times more intense than a 10-decibel sound. A 30-decibel sound is 100 times more intense than a 10-decibel sound. Sound levels for several sound sources are shown in the bar graph.
Sound Intensity
Decibels, or sound level; type of sound
Reading Graphs:
What unit of measure is represented on the y-axis? What is represented on the x-axis?
Section 15.4: Smell, Taste, and
Touch
What are the functions of the nervous system?What is the structure of a neuron and what kinds of neurons are found in the body?How do nerve impulses travel from one neuron to another?.
Touch
Touch receptors are the nerve cells that tell your brain about tactile sensations. There are two groups
(1) mechanoreceptors that tell you about sensations of pushing, pulling or movement,
(2) thermoreceptors that tell you about sensations of temperature.
Smell and Taste
The senses of smell and taste work closely together.
Both depend on chemicals in food or in the air.
The chemicals trigger responses in receptors in the nose and mouth.
Section 5: Alcohol
and Other Drugs
What are the functions of the nervous system?What is the structure of a neuron and what kinds of neurons are found in the body?How do nerve impulses travel from one neuron to another?
Illegal (Controlled) DrugsMarijuana
Methamphetamine
Cocaine
Narcotics
Hallucinogens
Depressants
Steroids
Inhalants
Tobacco • Kills More than all Other
Drugs Combined! 430,000 + Every Year!
• Second Hand Smoke
• Cancer, Heart Attacks
• Smokers’ Face/Breath/Teeth
• No Safe Way To Use
Alcohol
Alcohol is a drug found in many beverages, including beer, wine, cocktails, and hard liquor. Alcohol is a powerful depressant and affects every system of the body.
Alcohol • Health Risk• Fitness for Duty• Accidents• Drinking & Driving• Violence / Family• Underage Drinking
Excessive Drinking can Cause Problems with... Work, Family, Friends, Society, and Self
ALCOHOL IS A DEPRESSANT-IT SLOWS THE ACTIONS OF THE CENTRAL NERVOUS SYSTEM.
Marijuana• Strong
• Available
• 30 Million Users
• Reputation as a “safe” drug
• 15 Times Stronger than ‘70s
• Keeps People from Achieving Their Potential
• Often Laced w/ Other Drugs
• Hooks into Fat Cells
Cocaine & MethamphetamineIncreases
• Heart Rate
• Blood Pressure
• Activity
• Insomnia,
• Euphoria followed by Depression
• Neural Disruption
• “Wired”, Addiction
COCAINE vs. Methamphetamine
Crack vs. ICECoke=> Shorter, Bigger Surge
Ice=> Voices & Bugs, Paranoia, Violence
Cocaine
• Highly Addicting
• Dealing & Stealing
• High Dying Potential
• Often in Up/Down Combos => w/ Heroin
Methamphetamine - “Ice”
• High Potential for Violence, Addiction, & Death
• The Drug of Choice in Hawaii
• 2-3 Months Addiction Time
• Losing One’s Mind & Will
Ecstasy (Methamphetamine) vs.
Herbal Ecstasy (Ephedrine)
Ecstasy: Powerful Stimulant &
Hallucinogen
HallucinogensTherapeutic Use
Street Abuse
Army Testing Begins in 1989
Users Easy to Spot
Effects= Focus, Distortions, Nausea, Disorientation, Performance , Communications , Panic, TRAUMA
Hallucinogens
Effects: Focus X, Distortions, Nausea, Disorientation, Performance X, Communications X, Panic, TRAUMA
Depressants1950’s - Sleeping Pills1960’s - Barbiturates(Seconal & Phenobarbital)
Slowed Down, Sleepy; Impaired Thinking, Coordination; MoodSwings, Stressed heart
NARCOTICS
The Naturals: Opium, Morphine, Heroin
The Synthetics: Percodan, Demerol, Codeine
InhalantsThe Hidden Addiction:
Readily Available => Gas, Glue, Sprays, Paint, Polish, Cleaning Fluid, Medications, Poppers, White Out, Scented Pens....
InhalantsEffects: Feeling Light-Headed, Light-Sensitive, Sores, Nose Bleeds => Organ Damage, Bone Marrow, Increasing Dysfunction, Withdrawal, Addiction, Overdose
Inhalants
Things to Remember:
Very Short High,
Very High Dosage Rate,
High Addiction & Overdose Potential
Anabolic SteroidsInvented in 1935 – SYNTHETIC CHEMICALS SIMILAR TO HORMONES
Widely Used & Promoted in the ‘50s
Discouraged Use - 1960-1990
Non-Athlete Use: 1990s
Anabolic Steroids
• Effects= Building Muscle Mass
• stronger and faster.
• Puffy Face, Acne, Jaundice,
• Organ Damage,
• ROID RAGE !#@*#!
“Long Term use = Death” Excess Use Causes Too Many Changes, Too Fast
For The Body to Handle
Drug Abuse
Drug abuse can have serious consequences. However, there are ways to tell if someone is abusing drugs and ways to help that person.