1.3 The Neuron and Neural Firing Flashcards
Neuron
Type of cell that receives and sends messages from the body to the brain and back to the body.
Glial Cells
Any of the cells that hold nerve cells in place and help them work the way that they should.
Spinal cord
Carries nerve signals from your brain to the rest of your body, help you feel sensations, move your body, and keep breathing. (damage can affect your movement).
Reflex Arc
neural pathway that controls a reflex. Pass through synapse in spinal cord
Sensory Neurons
Carry messages IN from the bodys tissues and sensory receptors to the CNS for processing - EX: when you touch a hot surface with your fingertips, the sensory neurons will be the ones firing and sending off signals to the rest of the nervous system about the information they have received.
Motor Neurons
Carry instructions OUT from the CNS out to the bodys tissues. EX: pull our hand away when signals get to the spinal cord before the pain is felt in the brain
Interneurons
(in the brain and spinal cord) process information between the sensory input and motor output. EX: Trigger your hand to pull away from a fire before you can say ouch
All-or-None Response
The neuron recieves signals from other neurons some telling it to fire some telling it not to, when the threshold is reached, the action potential starts moving, it either fires or it doesnt, more stimulation does nothing this is known as all or none.
Depolarization
when there’s a shift in a neuron’s electrical charge that allows an action potential (nerve impulse) to occur (threshold) If it reaches the threshold, it triggers an action potential
Resting potential
The activation gates are closed and the membranes resting potential is maintained (polar)
refractory period
a period immediately following stimulation during which a nerve or muscle is unresponsive to further stimulation.
Reuptake: recycling neruotransmitters
After the nerurotransmitters stimulate the receptors on the recieving neuron, the chemicals are taken back up into the sending nueron to be used again.
Multiple Sclerosis
(MS) is a chronic disease that damages the central nervous system, causing a variety of symptoms that can affect movement, thinking, and feeling
Myasthenia Gravis
(MG) is a chronic autoimmune disorder in which antibodies destroy the communication between nerves and muscle, resulting in weakness of the skeletal muscles.
Excitatory
Excitatory neurotransmitters are chemical messengers that stimulate nerve cells, making them more likely to pass on a message to the next cell. (Glutamate, epinephrine)
Inhibitory
prevent chemical messages from being passed along to other nerve cells. This decreases the amount of stimulation nerve cells receive. - it regulates brain activity to prevent problems in the areas of anxiety, irritability, concentration, sleep, seizures and depression (GABA)
Action Potential
Information is passed down the axon of the neuron as an electrical impulse
Neurotransmitter
chemical messengers that your body can’t function without. Their job is to carry chemical signals (“messages”) from one neuron (nerve cell) to the next target cell. (Serotonin, Dopamine)
Acetylcholine
Type of Neurotransmitters that enables muscle action, learning, and memory, sleep (Myasthenia Gravis (MG) Produces antibodies that block these receptors - ACh deteriorate as Alzheimer’s progresses)
Dopamine
Influences movement, learning, attention, and emotion, reward pathway
(Oversupply - schizophrenia Under supply - ADHD)
Serotonin
Affects mood, hunger, sleep, and arousal (Undersupply linked to depression; some antidepressant drugs raise serotonin levels)
Norepinephrine
Helps control alertness and arousal ( Undersupply can depress mood and cause ADHD-like attention problems)
GABA
A major inhibitory neurotransmitter, reduces excitability ( Undersupply linked to seizures, tremors, and insomnia. Huntington’s, anxiety )
Glutamate
A major excitatory neurotransmitter; involved in memory
(Oversupply can overstimulate the brain, producing migraines or seizures; this is why some people avoid MSG (monosodium glutamate) in food)
Endorphins
body’s natural pain relievers and mood enhancers–produces pleasure when engaging in activities, reduced pain when hurt
(Low levels can lead to chronic pain or more sensitive to pain)
Substance P
helps transmit pain signals to the brain and spinal cord. P=Pain (Increased sensitivity to pain–like in neuropathy and rheumatoid arthritis, itchiness (eczema), or pain (migraines))
Endocrine System
Your endocrine system consists of the tissues (mainly glands) that create and release hormones.
Hormones
Hormones are chemical messengers released from endocrine glands that travel through the blood system to influence the nervous system to regulate behaviors
Adrenaline (Hormone)
Released from the adrenal glands, “fight or flight” hormone, increases heart rate, expands airways, boosts energy supply
- weight, blood pressure, sex drive, mood: addison’s disease causes weight loss, tired, low blood sugar, pain
Leptin (Hormone)
Adipocytes (fat cells) release leptin, high levels of body fat increase leptin production– Leptin regulates energy balance by signaling the brain (especially the hypothalamus) to reduce appetite and increase energy. Leptin plays a critical role in regulating appetite, metabolism, and energy balance. - Both too much and too little leptin can affect health, particularly weight and metabolic function. If there’s not enough leptin, the brain thinks the body is starving, leading to increased hunger and overeating.
Ghrelin (Hormone)
Produced by the stomach and, to a lesser extent, by the small intestine, pancreas, and brain. It is often referred to as the “hunger hormone” because it stimulates appetite, increases food intake, and promotes fat storage. Ghrelin plays an important role in regulating energy balance and body weight. - Excess ghrelin can lead to issues related to overeating and weight gain, with less ghrelin individuals may experience reduced appetite
Melatonin (Hormone)
produced by the pineal gland in the brain, Its main function is to regulate the body’s sleep-wake cycle - Too much = Excessive sleepiness and sleep disturbances. Too little = trouble falling/staying asleep
Oxytocin (Hormone)
produced mainly by the hypothalamus and released by the pituitary gland. It is often called the “love hormone” or “bonding hormone” childbirth, sexual arousal, milk production after childbirth, and emotional connection. - Imbalances can cause problems with stress/anxiety, emotional bonding and sensitivity
Agonists
Mimics Neurotransmitters - molecule fills the receptor site and activates it, acting like the Neurotransmitters (Opiate drugs)
Antagonist
Blocks neurotransmitters - Molecule fills the “lock” so that the neurotransmitter cannot get in and activate the receptor site (Botox)
Reuptake inhibitors
A type of drug that is used to treat depression and some other conditions. Selective serotonin reuptake inhibitors stop or delay the body from reabsorbing a substance called serotonin, which leaves more of it available for the body to use.
Psychoactive drugs
are chemicals introduced into the body which alter perceptions, mood, and other elements of conscious experience.
Stimulants (caffeine, cocaine)
Stimulants are drugs which intensify neural activity and bodily functions. (Dilated pupils, increased breathing and heart rate)
Depressants (alcohol)
chemicals that reduce neural activity and other body functions.
Hallucinogens (marijuana)
Drugs that impair motor coordination, perceptual ability, reaction time. Over time, the brain shrinks in areas processing memory and emotion.
Opioids (heroine)
depress nervous system activity; this reduces anxiety, and especially reduces pain.
Tolerance
of a drug refers to the diminished psychoactive effects after repeated use.
Tolerance feeds addiction because users take increasing amounts of a drug to get the desired effect.
Withdrawal
Painful symptoms of the body re-adjusting to the absence of the drug, worsens addiction because users want to resume taking the drug to end withdrawal symptoms.
Addiction/Dependance
someone feeling like they cannot function normally without the use of the substance. A drug dependence can be either physical or psychological and can have many negative effects on someone’s life.
