Unit 2: Biological Bases Flashcards
Neuron
A nerve cell, the basic building block of the nervous system
Cell Body
Part of the neuron that contains the nucleus, the cell’s life-support centre
Dendrites
A neutron’s (often bushy) branching extensions that receive and integrate messages, conducting impulses toward the cell body
Axon
The neuron extension that passes messages through its branches to other neurons or to muscles/glands
Myelin Sheath
Fatty tissue layer segmentally encasing the axons of some neurons, enables greater transmission speed
Glial Cells
Cells in the nervous system that support, nourish, and protect neurons. Also play a role in learning, thinking, and memory
Action Potential
A brief electrical charge that travels down an axon / a neural impulse
Threshold
Level of simulation required to trigger a neural impulse
Refractory Period
- A brief resting pause that occurs after a neuron has fired
- A resting period that occurs after orgasm.
The action cannot be repeated until things are returned to their resting state
All-or-None Response
A neuron’s reaction of either firing (with a full-strength response) or no firing
Synapse
Junction between the axon tip of the sending neuron and the dendrite/cell body of the receiving neuron
The gap at the junction is called the synaptic gap, or synaptic cleft
Neurotransmitters
Chemical messengers that cross the synaptic gaps between neurons. After crossing the synapse and binding to receptor sites on the receiving neuron, they influence whether the neuron will generate a neural impulse
Reuptake
A neurotransmitters reabsorption by the sending neuron
Endorphins
“Morphine within” - natural, opiate-like neurotransmitters linked to pain control and pleasure
Agonist
Molecule that increases a neurotransmitter’s action
Antagonist
Molecule that inhibits/blocks a neurotransmitter’s action
Nervous System
The body’s speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems
Central Nervous System
The brain and spinal cord
Peripheral Nervous System
The sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body
Nerves
Bundled axons that form neural cables connecting the central nervous system with muscles, glands, and sense organs
Sensory (Afferent) Neurons
Neurons that carry incoming information from the body’s tissues and sensory receptors to the brain and spinal cord
Motor (Efferent) Neurons
Neurons that carry outgoing information from the brain and spinal cord to the muscles and glands
Interneurons
Neurons within the brain and spinal cord that communicate internally and process information between the sensory inputs and motor outputs
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). Its sympathetic division arouses; its parasympathetic division calms
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
Reflex
A simple, automatic response to a sensory stimulus
Endocrine System
The body’s “slow” chemical communication system; a set of glands that secrete hormones into the bloodstream
Hormones
Chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues
Adrenal Glands
A 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
Pituitary Gland
The endocrine system’s most influential gland. Under the influences of the hypothalamus, it regulates growth and controls other endocrine glands
Lesion
Naturally or experimentally caused destruction of brain tissue
EEG (Electroencephalogram)
An amplified recording of the waves of electrical activity sweeping across the brain’s surface. Measured by electrodes placed on scalp
MEG (Magnetoencephalography)
A brain imaging technique that measures magnetic fields from the brain’s natural electrical activity
CT Scan (Computed Tomography)
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 (AKA CAT scan)
PET Scan (Positron Emission Tomography)
Visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task
MRI (Magnetic Resonance Imaging)
Technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue. MRI scans show brain anatomy
FMRI (Functional MRI)
Technique for revealing bloodflow and, therefore, brain activity by comparing successive MRI scans. fMRI scans show brain function as well as structure
Brain Stem
The oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull, responsible for automatic survival functions
Medulla
The base of the brainstem. Controls heartbeat and breathing
Reticular Formation
Nerve network that travels through the brainstem into the thalamus. Plays an important role in controlling arousal
Cerebellum
The “little brain” at the rear of the brainstem. Functions include processing sensory input, coordinating movement output and balance, and enabling nonverbal learning and memory
Limbic System
Neural system located below the cerebral hemispheres, associated with emotions and drives. Includes the amygdala, hypothalamus, and hippocampus
Amygdala
Two lima-bean sized neural clusters in the limbic system that are lined to emotions of fear or aggression
Hypothalamus
Neural structure below the thalamus. Directs several maintenance activities (eating, drinking, body temp), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward
Hippocampus
Neural centre located in the limbic system. Helps process storage for explicit (conscious) memories of facts and events
Cerebral Cortex
Intricate fabric of interconnected neural cells covering the cerebral hemispheres. The body’s ultimate control and information processing centre
Frontal Lobes
Portion of the cerebral cortex lying just behind the forehead, involved in speaking and muscle movements and in making plans and judgements
Parietal Lobes
Portion of the cerebral cortex lying at the top of the head and towards the rear that receives sensory input for touch and body position
Occipital Lobes
The portion of the cerebral cortex lying at the back of the head, that includes areas that receive information from the visual fields
Temporal Lobes
The portion of the cerebral cortex lying roughly above the ears that includes the auditory areas, each of which primarily receives information from the opposite ear
Motor Cortex
Area at the rear of the frontal lobes that controls voluntary movements
Somatosensory Cortex
Area at the front of the parietal lobes that registers and processes body touch and movement sensations
Association Areas
Areas of the cerebral cortex that are not involved in primary motor or sensory functions. Instead they are involved in higher mental functions such as learning, remembering, thinking, and speaking
Plasticity
The brains ability to change, especially during childhood, by reorganizing after damage or building new pathways based on experience
Neurogenesis
The formation of new neurons
Corpus Callosum
The large band of neural fibres connecting the two brain hemispheres and carrying messages between them
Split Brain
A condition resulting from a surgery that isolates the brain’s two hemispheres by cutting the fibres connecting them (mainly those in the corpus callosum)
Consciousness
Our subjective awareness of ourselves and our environment
Cognitive Neuroscience
Interdisciplinary study of the brain activity linked with cognition (including perception, thinking, memory, and language)
Dual Processing
Principle that information is often simultaneously processed on separate conscious and unconscious tracks
Blindsight
A condition in which a person can respond to a visual stimulus without consciously experiencing it
Parallel Processing
Processing many aspects of a problem simultaneously; the brains natural mode of information processing for many functions
Sequential Processing
Processing one aspect of a problem at a time; generally used to process new information or to solve difficult problems
Behaviour Genetics
The study of the relative power and limits of genetic and environmental influences on behaviour
Heredity
The genetic transfer of characteristics from parents to offspring
Environment
Every nongenetic influence, from prenatal nutrition to the people and things around us
Chromosomes
Threadlike structures made of DNA molecules that contain the genes
DNA (deoxyribonulic acid)
A complex molecule containing the genetic information that makes up the chromosomes
Genes
The biochemical units of heredity that make up the chromosomes; segments of DNA capable of synthesizing proteins
Genome
The complete instructions for making an organism, consisting of all the genetic material in that organism’s chromosomes
Identical (monozygotic) Twins
Develop from a single fertilized egg that splits in two, creating two genetically identical organisms
Fraternal (dizygotic) Twins
Develop from separate fertilized eggs. They are genetically no closer than ordinary brothers and sisters, but they share a prenatal environment.
Heritability
The proportion of variation among individuals in a group that we can attribute to genes. The heritability of a trait may vary, depending on the range of populations and environments studied.
Interaction
The interplay that occurs when the effect of one factor (such as environment) depends on another factor (such as heredity)
Molecular Genetics
The subfield of biology that studies the molecular structure and function of genes
Molecular Behaviour Genetics
The study of how the structure and function of genes interact with our environment to influence behavior
Epigenetics
The study of environmental influences on gene expression that occur without a DNA change
Evolutionary Psychology
The study of the evolution of behaviour and the mind, using principles of natural selection
Natural Selection
The principle that inherited traits are better enable an organism to survive and reproduce in a particular environment will (in competition with other trait variations) most likely be passed on to succeeding generations
Mutation
A random error in gene replication that leads to a change
Social Script
A culturally modelled guide for how to act in various situations
Paul Broca
Identified the part of the brain in the left frontal lobe that is responsible for speech production
Carl Wernicke
Identified the part of the brain in the left temporal lobe that is responsible for speech comprehension
Roger Sperry
Discovered that the brain is made of two hemispheres with unique functions
Michael Gazzaniga
Conducted research on split brain patients with an emphasis on understanding the left hemisphere as the speech centre of the brain
Charles Darwin
Emphasized the natural selection principle as a way of describing human needs for survival and adaptation
Sleep
A periodic, natural loss of consciousness- as distinct from unconsciousness resulting from a coma, general anaesthesia, or hibernation
Circadian Rhythm
Our biological clock; regular body rhythms (For example, of temperature and wakefulness) that occur on a 24-hour cycle
REM Sleep
Rapid eye movement sleep; a recurring sleep state during which vivid dreams commonly occur. Also known as paradoxical sleep, because the muscles are relaxed (except for minor twitches) but other body systems are active
Alpha Waves
The relatively slow brain waves of a relaxed, awake state
NREM Sleep
Non-rapid eye movement sleep; encompasses all sleep states except for REM sleep
Hallucinations
False sensory experiences, such as seeing something in the absence of an external visual stimulus
Hypnagogic Sensations
Bizarre experiences, such as jerking or a feeling of falling or floating weightlessly, which transitioning to sleep
Delta Waves
The large, slow brain waves associated with the deep sleep of NREM-3
Suprachiasmatic Nucleus (SCN)
A pair of cell cluster in the hypothalamus that controls circadian rhythm. In response to light, causes the pineal gland to adjust melatonin production, thus modifying our feelings of sleepiness
Insomnia
Recurring problems in falling or staying asleep
Narcolepsy
A sleep disorder characterized by uncontrollable sleep attacks. The sufferer may lapse directly into REM sleep, often at inopportune times
Sleep Apnea
A sleep disorder characterized by temporary cessations of breathing during sleep and repeated momentary awakenings
Night Terrors
A sleep disorder characterized by high arousal and an appearance of being terrified; occurs during NREM-3 sleep, within two or three hours of falling asleep, and are seldom remembered
Dream
A sequence of images, emotions, and thoughts passing through a sleeping person’s mind
Manifest Content
According to Freud, the symbolic, remembered story line of a dream
Latent Content
According to Freud, the underlying meaning of a dream
REM Rebound
The tendency for REM sleep to increase following REM sleep deprivation
Psychoactive Drug
A chemical substance that alters perceptions and moods
Substance Use Disorder
A disorder characterized by continued substance craving and use despite significant life disruption and/or physical risk
Tolerance
The diminishing effect with regular use of the same dose of a drug, requiring the user to take larger and larger doses before experiencing the drug’s effect
Withdrawal
The discomfort and distress that follow the discontinuing in an addictive drug or behavior
Depressants
Drugs (such as alcohol, barbiturates, and opiates) that reduce neural activity and slow body functions
Alcohol Use Disorder
(Popularly known as alcoholism) Alcohol use marked by tolerance, withdrawal, and a drive to continue problematic use
Barbiturates
Drugs that depress central nervous system activity, reducing anxiety but impairing memory and judgement
Opiates
Opium and its derivatives, such as morphine and heroin, depress neural activity, temporarily lessening pain and anxiety
Stimulants
Drugs (such as caffeine, nicotine, and the more powerful cocaine, amphetamines, methamphetamine, and ecstasy) that excite neural activity and speed up body functions
Nicotine
A stimulating and highly addictive psychoactive drug in tobacco
Cocaine
A powerful and addictive stimulant derived from the coca plant; produces temporarily increased alertness and euphoria
Amphetamines
Drugs, such as methamphetamine, that stimulate neural activity, causing accelerated body functions and associated energy and mood changes
Methamphetamines
A powerfully addictive drug that stimulates the central nervous system, with accelerated body functions and associated energy and mood changes; over time, appears to reduce baseline dopamine levels
Ecstasy (MDMA)
A synthetic stimulant and mild hallucinogen. Produces euphoria and social intimacy, but with short-term health risks and longer-term harm to serotonin-producing neurons and to mood and cognition
Hallucinogens
Psychedelic (“mind-manifesting”) drugs, such as LSD, that distort perceptions and evoke sensory images in the absence of sensory input
Near-Death Experience
An altered state of consciousness reported after a close brush with death (such a a cardiac arrest); often similar to drug induced hallucinations
LSD
A powerful hallucinogenic drug, also known as acid
THC
The major active ingredient in marijuana; triggers a variety of effects, including mild hallucinations
Sigmund Freud
Proposed that dreams have both manifest and latent content, emphasizing wish fulfilment in dream interpretation
William James
Created functionalist theory as well as the idea of a “stream of consciousness” where moments flow into one another despite alterations in our various states of consciousness
