Psych Unit 1a Notes
Nature and Genetics
Nature/Nurture Issue - the debate within psychology on whether people are more influenced by their genetics or their environment, with most psychologists saying that both have influence in different ways
Evolutionary Perspective - the psychological perspective of understanding behavior and the mind through the impact of natural selection
Natural Selection - when a population adapts based on what traits best help them to survive in an environment
Eugenics - the inept branch of science that believes in breeding a population based on favorable factors, rooted in bigotry
Genes - the biochemical units of heredity
Identical Twins - twins based on a separated egg, grown in the same placenta
Fraternal Twins - twins based on different eggs, grown in different placentas
Nervous System
Central Nervous System - the leading part of the nervous system, made up of the brain and spinal cord
Peripheral Nervous System - the part of the nervous system which connects the central nervous system made up of sensory and motor neurons to the body. It contains the somatic and autonomic nervous system
Somatic Nervous System - the division of the peripheral nervous system that controls the body’s skeletal muscles. Also called the skeletal nervous system
Autonomic Nervous System - the part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart). It contains the sympathetic and parasympathetic nervous systems
Sympathetic Nervous System - the division of the autonomic nervous system that arouses the body, mobilizing its energy
Parasympathetic Nervous System - the division of the autonomic nervous system that calms the body, conserving its energy
Glial Cell - the connective tissue in the nervous system, between neurons, and the most common cell in the nervous system. They support, nourish, and protect neurons; they may also play a role in learning, thinking, and memory
Neuron - the building block of the nervous system responsible for transmitting signals
Parts of the Neuron
Cell Body - the central part of the neuron that contains the nucleus; the cell’s life support system
Nucleus - A membrane-bound organelle that contains DNA and synthesizes proteins
Dendrites - the stringy parts of the neuron from the cell body that receive and integrate messages, conducting impulses towards the cell body
Axon - the long part of the neuron that passes messages through its branches to other neurons, muscles, or glands, and can be up to several feet long
Mylien Sheath - the fatty tissue covers of some axons which helps speed up neural signals
Nodes of Ranvier - the gaps between the myelin sheaths
Axon Hillock - the part that connects the cell body of the neuron to the axon of the neuron
Terminal Buds - stores and releases neurotransmitters into the synapse (the gap between neurons) to relay the message from one cell to the next
Vesicals - the little bubble package carrying neurotransmitters within the neuron
Synapse - the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. The tiny gap at this junction is called the synaptic gap or synaptic cleft
Receptor Site - proteins on the surface of neurons where neurotransmitters bind to
Reflex Arc - a simple, automatic response to a sensory stimulus, such as the knee-jerk reflex
Neurons
Sensory Neurons - the neurons responsible for sending information from the body’s tissues and sensory receptors to the central nervous system
Motor Neurons - the neurons that send signals from the central nervous system to the peripheral nervous system to conduct movement
Interneurons - neurons within the brain and spinal cord; they communicate internally and process information between the sensory inputs and motor outputs
Neural Transmission - the process of how neurons send signals to each other like dominoes
Resting Potential - when neurons have more negative ions within their membrane and positive ions outside, which is their natural position
Threshold - the required amount of energy needed for a neuron to react
All-or-nothing Principle - either a neuron fires or it doesn’t
Depolarization - when a neuron lets positive ions flow through its membrane
Refractory Period - the short period of time where a neuron is rebalancing and can’t take in any more signals
Reuptake - when neurons recollect remaining neurotransmitters at the synaptic cleft
Multiple sclerosis - when myelin sheaths don’t work properly, slowing down neural processes and making it harder for people to move and talk
Myasthenia gravis - when ACh (acetylcholine) transmission is blocked and muscles cannot contract, leading to weakness, difficulties with muscle control, and paralysis
Neurotransmitters
Neurotransmitters - chemical messengers that cross the synaptic gap between neurons. When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse
Excitatory Neurotransmitters - neurotransmitters that promote the firing of action potentials (electrical impulses) in the next neuron they connect to
Inhibitory Neurotransmitters - neurotransmitters that suppress the firing of action potentials in the next neuron they connect to
Dopamine - neurotransmitter for happiness, movement, learning, and attention. Oversupply leads to schizophrenia and undersupply linked to tremors and decreased mobility in Parkinson’s disease
Acetylcholine - neurotransmitter that enables muscle action, learning, and memory, and with Alzheimer’s disease, ACh-producing neurons deteriorate.
Serotonin - neurotransmitter that affects mood, hunger, sleep, and arousal. Undersupply is linked to depression, and some drugs for depression raise serotonin levels
Norepinephrine - neurotransmitter that helps control alertness and arousal, and undersupply can depress mood
Glutamate - a major excitatory neurotransmitter; involved in memory. Oversupply can overstimulate the brain, producing migraines or seizures
GABA - a major inhibitory neurotransmitter, and undersupply is linked to seizures, tremors, and insomnia
Endorphins - neurotransmitters that influence the perception of pain or pleasure, and with oversupply caused by opioid drugs, the body’s natural supply can be suppressed
Substance P - neurotransmitter responsible for receiving pain and pain tolerance, and an oversupply can lead to chronic pain
Hormones
Hormones - chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, affect other tissues, and last longer than neurotransmitters
Agonist - a molecule that increases a neurotransmitter’s action
Antagonist - a molecule that inhibits or blocks a neurotransmitter’s action
Adrenaline (epinephrine) - a hormone that increases heart rate, blood pressure, and blood sugar, providing a surge of energy to power flight or fight responses
Leptin - a hormone your body releases that helps it maintain your normal weight on a long-term basis. The level of leptin in your blood is directly related to how much body fat you have. Leptin resistance causes you to feel hungry and eat more even though your body has enough fat stores
Ghrelin - a hormone your stomach produces and releases. It signals your brain when your stomach is empty and it’s time to eat. Ghrelin levels increase between mealtimes and decrease when your stomach is full. People who have obesity often have low ghrelin levels, while people who significantly restrict their calorie intake have high ghrelin levels.
Melatonin - the hormone produced by pineal glands that is responsible for the circadian rhythm and sleeping
Oxytocin - the love hormone responsible for social bonding, reproduction, and maternal behavior. It enables orgasm, and in women labor contractions and milk flow
Psychoactive Drugs and Addiction
Substance Use Disorder - when a person becomes physiologically dependent on a substance to live a normal life because of prolonged/extensive use, and is unable to quit despite resulting life disruption
Psychoactive Drugs - a chemical substance that alters the brain, causing changes in perceptions and mood
Depressants - drugs that reduce neural activity and slow body functions
Alcohol - a depressant that slows brain activity that controls judgment and inhibitors, increases harmful tendencies, and contributes to over 200 diseases. The urges you feel when sober are the ones will be more likely to act upon when intoxicated
Stimulants - drugs that excite neural activity and speed up bodily functions that are often used to boost academic and athletic performance
Caffeine - a stimulant that is used to feel alert can impair sleep
Cocaine - a stimulant that enters the bloodstream, produces euphoria, stimulates the brain's reward pathway, depletes dopamine, serotonin, and norepinephrine. An agitated depression follows afterwards
Hallucinogens - psychedelic (“mind-manifesting”) drugs that distort perceptions and evoke sensory images in the absence of sensory input
Marijuana - a mild hallucinogen that amplifies sensitivity to colors, sounds, tastes, etc.. It relaxes and can produce a euphoric high, and is used for sleep or to boost mood. However, it impairs motor coordination, perceptual skills, and reaction time, and users develop tolerance. It can be “neurotoxic” at a young age - risk of anxiety, depression, suicidal behavior, psychosis later in life. It has some benefits - it alleviates chronic pain and improves sleep. THC lingers in the body for over a week while alcohol is cleaned up in hours.
Opioids - opium and its derivatives; they depress neural activity, temporarily lessening pain and anxiety. When addicted, people’s brains stop making natural opioids, worsening dependence
Heroin - an opioid, the prescribed synthetic counterpart is methadone
Tolerance - when a person uses a substance for a period of time and gets less of a reaction with the same dosage level, often causing them to increase dosage
Withdrawal - when a person is quitting a substance and experiences symptoms that makes them want to get back to using the substance, ranging from mild headaches to psychological pain and sickness
Misc. Brain and Brain Imaging
Aphasia - caused when a person experiences damage to certain parts of the brain (often Broca’s or Wernicke’s area), and are not able to communicate properly
Cortex Specialization - certain cortexes of the brain are responsible for certain functions. The left hemisphere is mostly responsible for language, symbolic thinking, detail, and literal meaning. The right hemisphere deals with spatial perception, the overall picture, metaphor, inferences, and modulating speech (how you speak with inflexion)
Contralateral Hemispheric Organization - the left hemisphere controls the right side of the body and the right hemisphere controls the left side of the body
Brain Plasticity - the ability of the brain to adapt, especially during childhood, to changes in the environment by reorganizing after damage or by building new pathways based on experience
EEG (electroencephalogram) - an amplified recording of the waves of electrical activity sweeping across the brain’s surface. These waves are measured by electrodes placed on the scalp
MRI (magnetic resonance imaging) - a technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue. MRI brain scans show brain anatomy
fMRI (functional MRI) - a technique for revealing blood flow and, therefore, brain activity by comparing successive MRI scans. fMRI scans show brain function as well as structure
Lesioning - when psychologists destroy a part of the brain to understand its functions or tissue is damaged naturally
CT (computed tomography) Scan - a series of X-ray photographs taken from different angles and combined by computer into a composite representation of a slice of the brain’s structure
PET (position emission tomography) Scan - a technique for detecting brain activity that displays where a radioactive form of glucose goes while the brain performs a given task