Ch. 3

  • 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 is thought to be important in processing 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 posses 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 developed 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 (MRI)

    • MRI that shows changes in metabolic activity over time

  • Genetic environmental correlation

    • view of gene-environment interaction that asserts our genes affect our environment, and our environment influence 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 transportation

  • Gonad

    • secretes sexual hormones, which are important for successful reproduction, and mediate both sexual motivation and behavior

  • Gyrus

    • bump or ridge in 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 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

  • Nerovous system

    • made up of billions of neurons and controls our thoughts, responses, and movements; divided into the central nervous system (CNS) and the peripheral nervous system (PNS)

  • 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 sense 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 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 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

    • 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 neurotransmitter

  • Temporal lobe

    • part of cerebral cortex associated with hearing, memory, emotion, and some aspect 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