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WARM UP 3/6, 3/6 DOUBLE. TAKE A DITTO OFF THE FRONT DESK From notes: Where is the myelin sheath? From notes: What does it do? Label on your warm up paper “NEURON DISORDERS” For each of the 4 diseases a. Name of disease b. What causes it c. What it does to the nerves
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WARM UP 3/6, 3/6 DOUBLE • TAKE A DITTO OFF THE FRONT DESK • From notes: Where is the myelin sheath? • From notes: What does it do? • Label on your warm up paper “NEURON DISORDERS” • For each of the 4 diseases • a. Name of disease • b. What causes it • c. What it does to the nerves • d. symptoms • d. One other fact
HEAVY METAL POISONING • Chronic exposure to heavy metals (lead, mercury) • Demyelination and glia cell damage • Affects physical and mental function • FACT
DIPTHERIA • Bacteria infection of the respiratory tract • Damages schwann cells and destroys the myelin sheath • Sensory and motor problems; fatal paralysis; heart problems • FACT
MULTIPLE SCLEROSIS • Genetic disease • Recurrent incidents of demyelination affecting axons of the optic nerve, brain, and spinal cord • Vision/ speech, balance, coordination problems • FACT
GUILLAIN-BARRE SYNDROME • Viral infection/ malfunction of immune system • Demyelination • Weakness of muscles • FACT
WARM UP 3/9 • What do afferent neurons do? • What cells help destroy microbes for the nervous system? • What does the oliodendroglia do? • What is a protective layer on the axon called? • What are the ends of dendrites called? • What are spaces between schwann cells called? • What type of neuron sends messages to the muscles or glands?
NOTES Ch 10 3/9 Neuron physiology
SYNAPSE – gap between neurons (junction) VESSICLES – sacs containing neurotransmitters NEUROTRANSMITTER – chemical that brings message across the synapse *they can excite – speed messages up or inhibit – slow messages down EX: Ach , Dopamine, GABA, Norepinepherine, Serotonin
RESTING POTENTIAL – when a neuron is not conducting impulses Membrane is –70mV (negative inside)
1. Something will stimulate a receptor in the body: EX: light, sound, pressure, taste, cold, hot….
2. Impulse reaches axon end 3. Neurotransmitter in vesicles released from synaptic knobs • NT travels across synapse 5. Attaches to receptors on dendrite of next neuron
6. Na+ rushes in – makes cell positive – DEPOLARIZATION 7.Action potential moves down neuron (leaps if myelinated)
When it reaches the axon end of the neuron, message goes to next neuron by doing steps 3-7 Continues until reaches a muscle, gland, or the brain
To stop impulse at synapse: 1. Enzymes can destroys NT 2. NT back to vesicles (uptake) When NT gone, Na+ goes out - cell becomes negative again - REPOLARIZATION
Resting neuron (-70mV) 9. DEPOLARIZATION Na+ rushes in and makes cell positive – creates an action potential (electrical current) 10. REPOLARIZATION Na+ rushes out and neuron becomes negative again Resting potential Depolarization Repolarization Action potential LABELING
Chemicals can affect the movement across the synapse • Stop creation of NT • Block NT from leaving vesicles • Bind to receptors in place of NT • Prevent Na+ from starting an AP • Prevent NT from uptake • Empty NT from vesicles • Have neuron become too negative
NEUROTOXINS • Made by animals for protection • Blocks many different receptors
NIOROCSP ROACB BAMAM PAWS KESTANLTRE CLABK DWOIW LUTARTAAN WRORA GFOR YOHEN EBE FLYEJLSIH **ASE MONAENE Unscramble the words of 10 common poisonous animals that produce a toxin that affects the nervous system. EXTRA CREDIT
ANOTHER EC! STIMULANT DEPRESSANT HALLUCIGEN NARCOTIC PCP Marijuana Nicotine Alcohol Ecstasy Caffeine Inhalants Heroin Morphine valium DRUGS
Depressants They slow down the amount of Na+ entering the neuron EX: Alcohol, valium, inhalants, barbituites, rohypnol Many inhalants are thought to dissolve the protective myelin sheath that surrounds neurons in brain cells - resulting in cell death
Slowed down messages from the brain to muscle impair our reflexes, reduce reaction time and impair our coordination, and our ability to drive is impaired. • Slurring of speech, stumbling when you walk, loss of balance. • Hand-eye coordination is reduced. • Thought and judgment are impaired because messages between the neurons in the brain are slowed down.
Rohypnol, “Roofies” is a very potent tranquilizer similar in nature to valium, but many times stronger. The drug produces a sedative effect, amnesia, muscle relaxation, and a slowing of psychomotor responses. Sedation occurs 20-30 minutes after administration and lasts for several hours.
It is commonly reported that persons who become intoxicated on a combination of alcohol and rohypnol have "blackouts" lasting eight to twenty-four hours following ingestion. Adverse effects of Rohypnol use include, decreased blood pressure, memory impairment, drowsiness, visual disturbances, dizziness, confusion, gastrointestinal disturbances and urinary retention. Withdrawal symptoms include headache, muscle pain, confusion, hallucinations and convulsions. Seizures may occur up to a week after use.
Known as the “date rape” drug – it is often slipped into a drink by an attacker. The drug has no taste or odor so the victims don't realize what is happening. About ten minutes after ingesting the drug, the woman may feel dizzy and disoriented, simultaneously too hot and too cold, or nauseated. She may experience difficulty speaking and moving, and then pass out. Such victims have no memories of what happened while under the drug's influence. • Be wary about accepting drinks from anyone you don't know well or long enough to trust. · If you are accepting a drink, make sure it's from an unopened container and that you open it yourself. • Don't put your drink down and leave it unattended, even to go to the restroom.
NEW TEST FOR THIS DRUG The strips were created by a person whose friend was a victim of a date-rape drug. They are easy to use. A drink straw can drip a few drops of a drink on the test strip. If the liquid turns blue, toss the drink. Other products in the range include a drinks coaster, designed with two areas that test for traces of date rape drugs. A drop of tainted liquid on the coaster will change the color of the cardboard. In the United States, the strips are available online at www.drinksafetech.com for 40 cents each.
NARCOTICS They attach to receptors and block NTs from binding (especially at pain receptors); can also make neuron too negative so longer for AP to start EX: opium, codeine, anethestics, morphine, heroin, demerol
Effects are similar to depressants and they have other effects that depressants do not have, which would include: • Pain relief • Suppress cough reaction
Stimulants They can increase release of NT and disrupt the clearing of NT in the synapse EX: Cocaine, Nicotine, Caffeine, Ritalin
Desired effects would include a sense of well being or euphoria, or an enhanced ability to think and function. • Other effects include anxiety, paranoia, increased heart rate, increased blood pressure, reduced appetite, restlessness, insomnia, and a feeling of being “shaky.”
NICOTINE Increase release of Ach (heightened activity – “wake up feeling) Releases endorphins (natural pain killers)
Hallucinogens Many mimic NTs EX: LSD, PCP, Mushrooms, Marijuana MDMA (ecstasy)
Distorts messages within the brain, and this can be felt as a distortion in perception. • Can cause hallucinations. • Milder hallucinogens are experienced as an enhancement of the senses: more sensitive to touch, pain can be magnified, music sounds better, hearing is altered, vision can be enhanced or blurred. • Our perception of time can be affected. • Thought processes are affected: poor short term memory, alternating inability to focus and enhanced ability to focus, reduced ability to learn • Other effects would include increased blood pressure, increased heart rate, and increased appetite.
ecstasy It can cause a sharp increase in body temperature leading to muscle breakdown and kidney and cardiovascular system failure. Brain imaging research in humans indicates that MDMA causes injury to the brain, affecting neurons that use the chemical serotonin to communicate with other neurons. The serotonin system plays a direct role in regulating mood, aggression, sleep, and sensitivity to pain. Many of the risks users face with MDMA use are similar to those found with the use of cocaine
Psychological difficulties, including confusion, depression, sleep problems, drug craving, severe anxiety, and paranoia - during and sometimes weeks after taking MDMA. • Physical symptoms such as muscle tension, involuntary teeth clenching, nausea, blurred vision, rapid eye movement, faintness, and chills or sweating. • Increases in heart rate and blood pressure, a special risk for people with circulatory or heart disease.
Research links MDMA use to long-term damage to those parts of the brain critical to thought and memory. One study, in primates, showed that exposure to MDMA for 4 days caused brain damage that was evident 6 to 7 years later.
Marijuana THC in marijuana mimics neurotransmitters and fits into receptor sites in the brain and stimulates those neurons When they copy the effects of the neurotransmitters, they are able to alter regular brain functions in these locations like memory and coordination. This explains why when you are high, you are disoriented and dizzy.
Chronic marijuana smokers are prey to chest colds, bronchitis, emphysema, and bronchial asthma. Persistent use will damage lungs and airways and raise the risk of cancer. And there is evidence that marijuana may limit the ability of the immune system to fight infection and disease. Marijuana also affects hormones. Regular use can delay the onset of puberty in young men and reduce sperm production. For women, regular use may disrupt normal monthly menstrual cycles and inhibit ovulation.
NERVE AGENTS • Chemical warfare used in wars • Read article about nerve agents and answer the questions : separate sheet