Organization of the Body and the Nervous System Chapter 31

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…

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Diseases and Drug Abuse Chapter 31

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

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

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

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

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

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

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

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

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

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

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

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

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

Methamphetamine Highly addictive synthetic stimulant http://www.montanameth.org/ 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.

The Senses Chapter 35 -4

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

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

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

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

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

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)

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