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4.8: Key Terms

  • Page ID
    200319
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    action potential
    electrical signal that moves down the neuron’s axon
    adrenal gland
    sits atop our kidneys and secretes hormones involved in the stress response
    agonist
    drug that mimics or strengthens the effects of a neurotransmitter
    all-or-none
    phenomenon that incoming signal from another neuron is either sufficient or insufficient to reach the threshold of excitation
    allele
    specific version of a gene
    amygdala
    structure in the limbic system involved in our experience of emotion and tying emotional meaning to our memories
    antagonist
    drug that blocks or impedes the normal activity of a given neurotransmitter
    auditory cortex
    strip of cortex in the temporal lobe that is responsible for processing auditory information
    autonomic nervous system
    controls our internal organs and glands
    axon
    major extension of the soma
    biological perspective
    view that psychological disorders like depression and schizophrenia are associated with imbalances in one or more neurotransmitter systems
    Broca’s area
    region in the left hemisphere that is essential for language production
    central nervous system (CNS)
    brain and spinal cord
    cerebellum
    hindbrain structure that controls our balance, coordination, movement, and motor skills, and it is thought to be important in processing some types of memory
    cerebral cortex
    surface of the brain that is associated with our highest mental capabilities
    chromosome
    long strand of genetic information
    computerized tomography (CT) scan
    imaging technique in which a computer coordinates and integrates multiple x-rays of a given area
    corpus callosum
    thick band of neural fibers connecting the brain’s two hemispheres
    dendrite
    branch-like extension of the soma that receives incoming signals from other neurons
    deoxyribonucleic acid (DNA)
    helix-shaped molecule made of nucleotide base pairs
    diabetes
    disease related to insufficient insulin production
    dominant allele
    allele whose phenotype will be expressed in an individual that possesses that allele
    electroencephalography (EEG)
    recording the electrical activity of the brain via electrodes on the scalp
    endocrine system
    series of glands that produce chemical substances known as hormones
    epigenetics
    study of gene-environment interactions, such as how the same genotype leads to different phenotypes
    fight or flight response
    activation of the sympathetic division of the autonomic nervous system, allowing access to energy reserves and heightened sensory capacity so that we might fight off a given threat or run away to safety
    forebrain
    largest part of the brain, containing the cerebral cortex, the thalamus, and the limbic system, among other structures
    fraternal twins
    twins who develop from two different eggs fertilized by different sperm, so their genetic material varies the same as in non-twin siblings
    frontal lobe
    part of the cerebral cortex involved in reasoning, motor control, emotion, and language; contains motor cortex
    functional magnetic resonance imaging (fMRI)
    MRI that shows changes in metabolic activity over time
    gene
    sequence of DNA that controls or partially controls physical characteristics
    genetic environmental correlation
    view of gene-environment interaction that asserts our genes affect our environment, and our environment influences the expression of our genes
    genotype
    genetic makeup of an individual
    glial cell
    nervous system cell that provides physical and metabolic support to neurons, including neuronal insulation and communication, and nutrient and waste transport
    gonad
    secretes sexual hormones, which are important for successful reproduction, and mediate both sexual motivation and behavior
    gyrus
    (plural: gyri) bump or ridge on the cerebral cortex
    hemisphere
    left or right half of the brain
    heterozygous
    consisting of two different alleles
    hindbrain
    division of the brain containing the medulla, pons, and cerebellum
    hippocampus
    structure in the temporal lobe associated with learning and memory
    homeostasis
    state of equilibrium—biological conditions, such as body temperature, are maintained at optimal levels
    homozygous
    consisting of two identical alleles
    hormone
    chemical messenger released by endocrine glands
    hypothalamus
    forebrain structure that regulates sexual motivation and behavior and a number of homeostatic processes; serves as an interface between the nervous system and the endocrine system
    identical twins
    twins that develop from the same sperm and egg
    lateralization
    concept that each hemisphere of the brain is associated with specialized functions
    limbic system
    collection of structures involved in processing emotion and memory
    longitudinal fissure
    deep groove in the brain’s cortex
    magnetic resonance imaging (MRI)
    magnetic fields used to produce a picture of the tissue being imaged
    medulla
    hindbrain structure that controls automated processes like breathing, blood pressure, and heart rate
    membrane potential
    difference in charge across the neuronal membrane
    midbrain
    division of the brain located between the forebrain and the hindbrain; contains the reticular formation
    motor cortex
    strip of cortex involved in planning and coordinating movement
    mutation
    sudden, permanent change in a gene
    myelin sheath
    fatty substance that insulates axons
    neuron
    cells in the nervous system that act as interconnected information processors, which are essential for all of the tasks of the nervous system
    neuroplasticity
    nervous system's ability to change
    neurotransmitter
    chemical messenger of the nervous system
    Nodes of Ranvier
    open spaces that are found in the myelin sheath that encases the axon
    occipital lobe
    part of the cerebral cortex associated with visual processing; contains the primary visual cortex
    pancreas
    secretes hormones that regulate blood sugar
    parasympathetic nervous system
    associated with routine, day-to-day operations of the body
    parietal lobe
    part of the cerebral cortex involved in processing various sensory and perceptual information; contains the primary somatosensory cortex
    peripheral nervous system (PNS)
    connects the brain and spinal cord to the muscles, organs and senses in the periphery of the body
    phenotype
    individual’s inheritable physical characteristics
    pituitary gland
    secretes a number of key hormones, which regulate fluid levels in the body, and a number of messenger hormones, which direct the activity of other glands in the endocrine system
    polygenic
    multiple genes affecting a given trait
    pons
    hindbrain structure that connects the brain and spinal cord; involved in regulating brain activity during sleep
    positron emission tomography (PET) scan
    involves injecting individuals with a mildly radioactive substance and monitoring changes in blood flow to different regions of the brain
    prefrontal cortex
    area in the frontal lobe responsible for higher-level cognitive functioning
    psychotropic medication
    drugs that treat psychiatric symptoms by restoring neurotransmitter balance
    range of reaction
    asserts our genes set the boundaries within which we can operate, and our environment interacts with the genes to determine where in that range we will fall
    receptor
    protein on the cell surface where neurotransmitters attach
    recessive allele
    allele whose phenotype will be expressed only if an individual is homozygous for that allele
    resting potential
    the state of readiness of a neuron membrane’s potential between signals
    reticular formation
    midbrain structure important in regulating the sleep/wake cycle, arousal, alertness, and motor activity
    reuptake
    neurotransmitter is pumped back into the neuron that released it
    semipermeable membrane
    cell membrane that allows smaller molecules or molecules without an electrical charge to pass through it, while stopping larger or highly charged molecules
    soma
    cell body
    somatic nervous system
    relays sensory and motor information to and from the CNS
    somatosensory cortex
    essential for processing sensory information from across the body, such as touch, temperature, and pain
    substantia nigra
    midbrain structure where dopamine is produced; involved in control of movement
    sulcus
    (plural: sulci) depressions or grooves in the cerebral cortex
    sympathetic nervous system
    involved in stress-related activities and functions
    synaptic cleft
    small gap between two neurons where communication occurs
    synaptic vesicle
    storage site for neurotransmitters
    temporal lobe
    part of cerebral cortex associated with hearing, memory, emotion, and some aspects of language; contains primary auditory cortex
    terminal button
    axon terminal containing synaptic vesicles
    thalamus
    sensory relay for the brain
    theory of evolution by natural selection
    states that organisms that are better suited for their environments will survive and reproduce compared to those that are poorly suited for their environments
    threshold of excitation
    level of charge in the membrane that causes the neuron to become active
    thyroid
    secretes hormones that regulate growth, metabolism, and appetite
    ventral tegmental area (VTA)
    midbrain structure where dopamine is produced: associated with mood, reward, and addiction
    Wernicke’s area
    important for speech comprehension

    This page titled 4.8: Key Terms is shared under a not declared license and was authored, remixed, and/or curated by OpenStax.

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