Unit 2 Flashcards
Define neuron
Nerve cell; building block of nervous system
Define dendrites
Neuron’s extensions that receive messages and conduct impulses towards cell body
Define axon
Neuron extension that passes messages through its branches to other neurons, or to muscles or glands
Define myelin sheath
Fatty tissue layer encasing axons of neurons; enables greater transmission speed as neural impulses travel between nodes
Define action potential
Neural impulse; brief electrical charge that travels down an axon
Define refractory period
Period of inactivity after neuron has fired
Define threshold
Level of stimulation required to trigger a neural impulse
Define all-or-none response
Neuron’s reaction of either firing with a full strength response or not firing
Define synapse
Junction between axon tip of the sending neuron and the dendrite or cell body of the receiving neuron
Define neurotransmitters
Chemical messengers that cross synaptic gaps between neurons
Travel across synapse to bind to receptor sites, influencing whether that neuron will generate a neural impulse
Define reuptake
Neurotransmitter’s reabsoprtion by the sending neuron
Define endorphins
Natural, opiate-like neurotransmitters linked to pain control and to pleasure
Define agonist
Molecule that, by binding to a receptor sites, stimulates a response
Define antagonist
A molecule that, by binding to a receptor site, inhibits or blocks a response
Define nervous system
Electrochemical communication network, consisting of all the nerve cells in the peripheral and central nervous system
What does the central nervous system consist of?
The brain and spinal cord
What does the peripheral nervous system consist of?
The sensory and motor neurons that connect the central nervous system to the rest of the body
Define nerves
Bundled axons that form neural cables connecting the central nervous system with muscles, glands, and sense organs
Define sensory/afferent neurons
Neurons that carry incoming information from the sensory receptors to brain and spinal cord
Define motor/efferent neurons
Neurons that carry outgoing information from the brain and spinal cord to the muscles and glands
Define interneurons
Neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs
Define somatic nervous system
Division of the peripheral nervous system that controls the body’s skeletal muscles
Define autonomic nervous system
Division of the peripheral nervous system that controls the glands and muscles of internal organs
Define sympathetic nervous system
Division of the autonomous nervous system that arouses the body, mobilizing its energy in stressful situations
Define parasympathetic nervous system
Division of the autonomous nervous system that calms the body, conserving its energy
Define reflex
Simple, autonomic response to a sensory stimulus
example: knee-jerk response
Define endocrine system
Body’s slow chemical communication system
Set of glands that secrete hormones into bloodstream
Define hormones
Chemical messengers that are manufactured by endocrine glands travel through bloodstream and affect other tissues
Define adrenal glands
Pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress
Define pituitary gland
Endocrine system’s most influential gland
Under control of hypothalamus, it regulates growth and controls other endocrine glands
Define lesion
Tissue destruction
Brain lesion is naturally or experimentally caused destruction of brain tissue
Define EEG (electroencephalogram)
Amplified recording of waves of electrical activity sweeping across brain’s surface
Waves are measured by electrodes placed on scalp
Define CT scan (computed tomography)
Series of x-ray photographs taken from different angles combined by computer into a representation of a slice of brain structure
Define PET scan (positron emission tomography)
Visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a task
Define MRI (magnetic resonance imaging)
Technique using magnetic fields and radio waves to produce computer-generated images of soft tissue
Shows brain anatomy
Define fMRI (functional MRI)
Technique that reveals bloodflow, and therefore brain activity by comparing successive MRI scans
Shows brain function and structure
Define brainstem
Oldest part and central core of the brain that begins where the spinal cord swells as it enters the skull
Responsible for automatic survival functions
Define medulla
Base of the brainstem that controls heartbeat and breathing
Define thalamus
Brain’s sensory control center located on top of the brainstem
Directs messages to sensory-receiving areas in the cortex and transmits replies to cerebellum and medulla
Define reticular formation
Nerve network that travels through the brainstem and thalamus
Plays an important role in controlling arousal
Define cerebellum
Located at the rear of the brainstem
Processes sensory input, coordinating movement output and balance, and enabling nonverbal learning and memory
Define limbic system
Neural system (hippocampus, amygdala, and hypothalamus) located below the cerebral hemispheres
Associated with emotions and drives
Define amygdala
2 neural clusters in the limbic system that are linked to emotion
Define hypothalamus
Neural structure lying below the thalamus
Directs maintenance activities like eating, drinking, and body tempterature
Helps govern endocrine system via the pituitary gland
Linked to emotions and reward
Define cerebral cortex
Intricate fabric of interconnected neural cells covering the cerebral hemispheres
Body’s ultimate control and information-processing center
Define glial cells
Cells in the nervous system that support, nourish, and protect neurons
May play a role in learning and thinking
Define frontal lobes
Portion of cerebral cortex lying behind the forehead
Involved in speaking, muscle movements, and making plans and judgements
Define parietal lobes
Portion of cerebral cortex lying at the top of the head toward the rear
Receives sensory input for touch and body position
Define occipital lobes
Portion of cerebral cortex lying at the back of the head
Receive information from visual fields
Define temporal lobes
Portion of cerebral cortex lying above the ears
Includes auditory areas that receive information from the opposite ear
Define motor cortex
Area at the rear of frontal lobes that controls voluntary movements
Define somatosensory cortex
Area at the front of parietal lobes that registers and processes body touch and movement sensations
Define association areas
Areas of the cerebral cortex that involve higher mental functions such as learning, remembering, thinking, and speaking
Define plasticity
Brain’s ability to change, especially during childhood, by reorganizing after damage or building new pathways based on experience
Define neurogenesis
Formation of new neurons
Define corpus callosum
Large band of neural fibers connecting the 2 brain hemispheres and carries messages between them
Define split brain
Condition resulting from surgery that isolated brain’s 2 hemispheres by cutting the corpus callosum fibers connecting them
Define consciousness
Our awareness of ourselves and our environment
Define dual processing
Principle that information is often simultaneously processed in conscious and unconscious tracks
Define behavior genetics
Study of relative power and limits of genetic and environmental influences on behavior
Define environment
Every external influence from prenatal nutrition to the people and things around us
Define chromosomes
Threadlike structures made of DNA that contain genes
Define DNA (deoxyribonucleic acid)
Complex molecule containing genetic information that makes up chromosomes
Define genes
Biochemical units of hereditary that make up chromosomes
Segments of DNA that synthesize proteins
Define genome
Complete instructions for making an organism consisting of all the genetic material in its chromosomes
Define identical/monozygotic twins
Twins who develop from a single fertilized egg that splits in 2
Genetically identical
Define fraternal/dizygotic twins
Twins who develop from separate fertilized eggs that share a fetal environment
Genetically the same as brothers and sisters
Define molecular genetics
Subfield of biology that studies the molecular structure and function of genes
Define heritability
The proportion of variation among individuals that we can attribute to genes
May vary depending on populations and environments
Define interaction
Interplay that occurs when the effect of one factor, like environment, depends on another factor, like hereditary
Define epigenetics
Study of environmental influences on gene expression that occur without DNA change
Define mutation
A random error in gene replication that leads to a change
Define hypnosis
Social interaction where 1 person responds to another person’s suggestions that certain perceptions, feelings, thoughts, or behaviors will spontaneously occur
Define posthypnotic suggestion
A suggestion made during a hypnosis session to be carried out after the subject is no longer hypnotized
Used by clinicians to help control undesired symptoms and behaviors
Define dissociation
A split in consciousness which allows thoughts and behaviors to occur simultaneously with others
Define circadian rhythm
The biological clock
Regular bodily rhythms that occur on a 24-hour cycle like temperature and wakefulness
Define REM sleep
Rapid eye movement sleep
A recurring sleep stage during which vivid dreams commonly occur and muscles are relaxed but other body systems are active
Define alpha waves
Relatively slow brain waves of a relaxed, awake state
Define sleep
Periodic, natural loss of consciousness
Define hallucinations
False sensory experiences like seeing something in the absence of an external visual stimulus
Define delta waves
Large, slow brain waves associated with deep sleep
Define NREM sleep
Non-rapid eye movement sleep
Encompasses all sleep stages except for REM sleep
Define SCN (suprachiasmatic nucleus)
Pair of cell clusters in the hypothalamus that controls circadian rhythm
In response to light, SCN causes pineal gland to adjust melatonin production, modifying sleepiness
Define insomnia
Recurring problems in falling or staying asleep
Define narcolepsy
Sleep disorder characterized by uncontrollable sleep attacks
Sufferer may lapse directly into REM sleep at bad times
Define sleep apnea
Sleep disorder characterized by temporary cessations of breathing during sleep and repeated momentary awakenings
Define night terrors
Sleep disorder characterized by high arousal and an appearance of being terrified
Occur during NREM-3 sleep within 2-3 hours of falling asleep and are rarely remembered
Define dream
Sequence of images, emotions, and thoughts passing through a sleeping person’s mind
Notable for hallucinatory imagery, discontinuities, incongruities, delusional acceptance of content, and difficulty remembering it
Define manifest content
According to Freud, remembered story line of a dream
Define latent content
According to Freud, the underlying meaning of a dream
Define REM rebound
Tendency for REM sleep to increase following REM sleep deprivation
Define substance use disorder
Continued substance craving and use despite significant life disruption and/or physical risk
Define psychoactive drug
Chemical substance that alters perceptions and moods
Define tolerance
Diminishing effect with regular use of the same dose of a drug, requiring user to take larger and larger doses before experiencing the drug’s effect
Define addiction
Compulsive craving of drugs or certain behaviors despite known adverse consequences
Define withdrawal
Discomfort and distress that follow discontinuing an addictive drug or behavior
Define depressants
Drugs that reduce neural activity and slow body functions
Alcohol, barbiturates, and opiates
Define alcohol use disorder AKA alcoholism
Alcohol use marked by tolerance, withdrawal, and a drive to continue problematic use
Define barbiturates
Drug that depress central nervous system activity, reducing anxiety but impairing memory and judgment
Define opiates
Opium and its derivatives like morphine and heroin
Depress neural activity, temporarily lessening pain and anxiety
Define stimulants
Drugs that excite neural activity and speed up body functions
Caffeine, nicotine, cocaine, ecstasy
Define amphetamines
Drugs that stimulate neural activity, causing sped up body functions, and associated energy and mood changes
Define nicotine
Stimulating and highly addicting psychoactive drug in tobacco
Define cocaine
Powerful and addictive stimulant, derived from the coco plant, producing temporary increased alertness and euphoria
Define methamphetamine
Powerfully addictive drug that stimulates central nervous system with sped up functions and associated energy and mood changes
Appears to reduce baseline dopamine levels over time
Define ecstasy (MDMA)
Synthetic stimulant and mild hallucinogen
Produces euphoria and social intimacy, but with short term health risks and long term harm to serotonin-producing neurons, mood, and cognition
Define hallucinogens
Psychedelic drugs such as LSD that distort perceptions and evoke sensory images in the absence of sensory input
Define LSD
Powerful hallucinogen drug, AKA acid
Define near-death experience
An altered state of consciousness reported after a close brush with death
Similar to drug-induced hallucinations
Define THC
Major active ingredient in marijuana that triggers a variety of effects, including mild hallucinations
