1. Organization of the Body and the Nervous System
Chapter 31

2. Organization of the Human Body
1. Cells
smallest unit still considered to be living
all living things are composed of cells
100 trillion cells in an adult
(ex) nerve cells, muscle cells, blood cells, etc…

3. Organization of the Human Body
2. Tissues =
groups of similar cells with one function
Muscle Cells Muscle Tissue
(ex) nerve tissue, muscle tissue, etc…

4. Organization of the Human Body
3. Organs =
groups of tissues that perform one function
Muscle Tissue The Heart
(ex) eye, kidney, lung, intestine, stomach

5. Organization of the Human Body
4. Organ Systems
a group of organs with one function
The Heart and Blood Vessels Circulatory System
11 major body systems
Nervous, Endocrine, Circulatory, Respiratory, Digestive, Excretory, Immune, Reproductive, Skeletal, Muscular, Integumentary

6. Homeostasis “keeping things in balance”
the process by which organisms keep internal conditions relatively constant despite changes in external environment
(ex) maintaining body temperature

7. Nervous System Function
Controls and coordinates the functions of the body
respond to external and internal stimuli
Control Center and Telephone Lines

8. Neurons: carry electrical signals (impulses) throughout the body
3 Types of Neurons:
Sensory Neurons = carry impulses from sense organ to brain
Motor Neurons = carry impulses from the brain to muscles
Interneurons = connect sensory neurons and motor neurons and carry impulses between them
Nerve Cells

9. 3 Parts of the Neuron 1. Cell Body: collects the messages
2. Dendrites: carries the message to the cell body
3. Axon: carries the message away from the cell body

10. Nerve Tissue Nerve Tissue = bunch of Neurons
Impulse = the electrical message being passed from one neuron to another (telephone game)

11. Nerve Tissue
Myelin = insulation around neuron, makes the impulse travel faster
Synapse = where the impulse jumps from one neuron to the next

12. Divisions of the Nervous System
Central Nervous System
control center
relays messages, processes information, and analyzes information
Organs = brain and spinal cord

13. Divisions of the Nervous System
Peripheral Nervous System
receives information from the environment and
relays commands to the organs and glands
sensory and motor divisions
all nerves not associated with spinal cord

14. Nervous System Organs Brain 100 billion cells = lots of energy
control center
3 regions:
Cerebrum = learning, intelligence
Cerebellum = muscle movement
Brain Stem = breathing, heart rate, swallowing

15. Nervous System Organs Spinal Cord
link between your brain and the rest of the body
used for support and protection in vertebrates
Surrounded in spinal fluid

16. Nervous System Organs Peripheral Nervous System
the nerves that branch from the spinal cord
ability to move

17. Somatic Nervous System
Regulates activities that are under conscious control
movement of skeletal muscles
response to pain, temperature, reflexes

18. Autonomic Nervous System
Regulates activities that are automatic or involuntary
speeding up of heart beat and blood flow during exercise
digestive processes

19. Diseases and Drug Abuse
Chapter 31

20. Spinal Injuries Head, neck and back injuries
Falling from 1.5x’s your height
Moving vehicle/animal accidents
results in brain damage, paralysis, loss of body control

21. Alzheimer’s Disease
Loss of memory/dementia damage to cerebrum (memory)
Caused by a loss of cells (swiss cheese) or neurons tangled (knots)
no cure
affects 50% of people over 85 yrs old

22. Meningitis
Infection of the fluid surrounding the brain and spinal cord
bacterial or viral (more sever if bacterial)
spreads easily from person to person (schools/dorms)
vaccination is available

23. Parkinson’s Disease Damage to neurons in the cerebellum
loss of muscle control (shaking)
caused by genetics (inherited), use of illegal drugs, or extreme head injury
Michael J Fox, Muhammad Ali

24. West Nile Virus Virus causes encephalitis (swelling of the brain)
headaches, fever, coma, death
spread by mosquitoes

25. Drugs
Any substance, other than food, that changes the structure of function of the body
positive and negative effects
all are harmful if used improperly

26. Drugs that Affect the Nervous System
Most drugs affect the synapse region
damaged synapse = messages can’t travel from neuron to neuron
body is unable to respond to environment

27. Stimulants
increases the release of neurotransmitters at synapses in the brain
increase heart rate, blood pressure, breathing rate
Result = High (energy/happy) then Low (tired/unhappy)
Long Term = heart problems, depression hallucinations
Examples = amphetamines, cocaine, nicotine, caffeine

28. Depressants
Enhance the effects of neurotransmitters, decrease the rate of brain function
slow heart and breathing rate, lower blood pressure, relax muscles
easily addicted, fatal when mixed
examples = tranquilizers, alcohol, barbiturates

29. Cocaine Causes an increase in the release of dopamine from the brain
Dopamine causes intense feeling of pleasure or satisfaction
After cocaine wears off, dopamine levels are low = depression, cravings
highly addictive, increase heart and blood pressure, permanent heart damage, loss of control

30. Opiates Pain-killing drugs from the center of opium poppies
mimic endorphins in the brain and help you to overcome pain
body gets used to drug (lowers endorphin levels)
Stop taking = low endorphin levels = pain, sickness
Examples = codeine, morphine, heroin

31. Marijuana Most widely abused illegal drug
contains THC (tetrahydrocannabinol)
THC causes temporary euphoria or disorientation
Very bad for lungs (no filter)
Long term effects = loss of memory and ability to concentrate, lower levels of testosterone

32. Alcohol Depressant which slows the rate at which the CNS functions
slows down reflexes, disrupts coordination, and impairs judgement
40% of deadly car accidents
1/3 of homicides
$150 billion per year
Fetal Alcohol Syndrome (50,000/year)
Liver Failure

33. Methamphetamine Highly addictive synthetic stimulant
Methamphetamine
Highly addictive synthetic stimulant
More addictive than heroin
Meth is sometimes referred to as "Speed," "Chalk," "Ice," "Crystal," "Glass," "Crank," "Yaba," "Fire," Tina," and "Tweak."
Symptoms: Brain damage, respiratory problems, irregular heartbeat, irreversible damage to blood vessels in the brain, strokes, heart attacks, kidney damage, cardiovascular collapse, and death.
In Montana alone
52% of children in foster care are there due to Meth.
50% of adults in prison are there due to Meth-releated crime.
20% of adults in treatment are there for Meth addiction.

34. The Senses
Chapter 35 -4

35. Sensory Receptors
Neurons that react directly to stimuli in the environment
Concentrated in sense organs
5 Categories
pain receptors: respond to damaged cells
thermoreceptors: variations in temperature
mechanoreceptors: touch, pressure, sound, motion
chemoreceptors: chemicals in the enviro
photoreceptors: sensitive to light

36. Responding to Stimuli 1. Sense organ detects stimuli
2. Neurons carry impulse
3. Brain decides how to respond
4. Neurons carry message away from brain to the part of the body that will respond

37. Vision Sense Organ = eyes
photoreceptors convert light energy into nerve impulses that are carried to the brain
the brain forms one image and interprets the image

38. Hearing Sensory Organ = Ear
Mechanoreceptors convert sound waves into nerve impulses that are carried to the brain
Brain interprets language and distinguishes between pitch and loudness

39. Smell Sense Organ = nose
Chemoreceptors in the nose detect chemicals and convert them into nerve impulses that are carried to the brain
Brain interprets smells (good, bad, what is it?)
Can’t smell when stuffed up

40. Taste Sense Organs = Nose and Taste Buds
Chemoreceptors in the nose detect chemicals from the food and turn it into an impulse
the brain determines what you are eating and your opinion
chemoreceptors in taste buds detect different tastes (sweet, salty, sour, bitter)

41. Touch Sense Organ = skin
3 different receptors to detect temperature, touch, and pain
Concentrated in areas (fingers, toes, face)