Biological Psychology: Nerve Cells, Nerve Impulses, and Synapses

Vocabulary flashcards covering biological psychology concepts, fields of specialization, cellular structure, nerve impulses, synaptic events, neurotransmitters, and basic neurochemistry.

Biological psychology

The study of the physiological, evolutionary, and developmental mechanisms of behavior and experience.

Complacency

Thinking there is nothing more to discover because humans are already assumed to be completely different.

Defeatism

Believing that trying to find evolutionary or animal origins of human behavior is pointless because the gap supposedly cannot be explained.

Mind-brain problem

The question of how mind relates to brain activity, specifically how brain activity produces the mind and consciousness.

Monism

The view that the mind and brain are not two separate substances.

Dualism

The view that mind and matter are two different types of things.

Physiological explanation

An explanation that relates a behavior to the activity of the brain and other body organs.

Ontogenetic explanation

An explanation that describes how a structure or behavior develops, including the influences of genes, nutrition, experiences, and their interactions.

Evolutionary explanation

An explanation that reconstructs the evolutionary history of a structure or behavior.

Functional explanation

An explanation that describes why a structure or behavior evolved as it did.

Genetic drift

When a gene becomes more or less common in a population because of chance, especially in a small, isolated population.

Neuroscientist

A researcher who studies the nervous system, especially its anatomy, biochemistry, and physiology.

Behavioral neuroscientist

A specialist who investigates how the functioning of the brain and other organs influences behavior.

Cognitive neuroscientist

A researcher who uses brain scans and research to analyze and explore human knowledge, thinking, and problem solving.

Neuropsychologist

A professional who conducts behavioral tests to determine the abilities and disabilities of people with brain damage.

Psychophysiologist

A specialist who measures heart rate, breathing rate, brain waves, and other body processes to study physiological responses to psychological stimuli.

Neurochemist

A scientist who investigates chemical processes and reactions occurring in the brain.

Comparative psychologist

A researcher who compares the behaviors of different animal species and relates them to their ways of life.

Evolutionary psychologist

A specialist who relates behaviors to the evolutionary functions they served and the presumed selective pressures that shaped them.

Clinical psychologist

A practitioner who helps people experiencing emotional, behavioral, or psychological problems.

Counseling psychologist

A professional who helps people make educational, vocational, personal, and adjustment decisions.

School psychologist

A practitioner who identifies educational needs of schoolchildren, devises plans to meet those needs, and assists teachers.

Neurologist

A physician who diagnoses and treats diseases or disorders of the brain and nervous system.

Neurosurgeon

A physician who performs surgical treatment on the brain and nervous system.

Psychiatrist

A medical doctor who helps people experiencing emotional distress or troublesome behaviors, often using drugs or medical procedures.

Physical therapist

An allied health professional who provides exercise and treatments to help people improve movement and physical functioning.

Occupational therapist

A practitioner who helps people improve or regain their ability to perform activities of daily life.

Social worker

A professional who helps people deal with personal, family, and social problems.

Minimalists

People who believe animal research is acceptable under strict limits, considering research value, animal distress, and species.

The Three R's

Ethical standards in animal research consisting of Reduction, Replacement, and Refinement.

Abolitionists

People who contend that animals have the same rights as humans and should never be used for research under any circumstances.

Institutional Animal Care and Use Committee (IACUC)

A committee of veterinarians, community representatives, and scientists that evaluates proposed animal experiments.

Santiago Ramón y Cajal

A Spanish investigator who demonstrated that the brain is composed of individual, separate cells that communicate with one another.

Camillo Golgi

An Italian investigator who believed that neurons are physically merged together into one continuous network.

Plasma membrane

The cell structure that controls what enters and leaves the cell.

Nucleus

An organelle that contains the chromosomes and genetic information.

Mitochondria

Organelles that produce energy for the cell.

Ribosomes

Structures that synthesize proteins for the cell.

Endoplasmic reticulum

A network of folded membranes that transports proteins and other materials within the cell.

Dendrites

Branching fibers of a neuron that receive information from other cells and carry it toward the soma.

Dendritic spines

Short outgrowths on dendrites that increase the surface area available for synapses.

Soma

The cell body of a neuron, containing the nucleus, ribosomes, and mitochondria, responsible for most metabolic work.

Axon

A long, thin fiber of constant diameter that conveys an impulse away from the cell body toward other cells.

Myelin sheath

An insulating layer of fatty and protein material wrapping around an axon to speed signal transmission.

Nodes of Ranvier

Interruptions or gaps in the myelin sheath where voltage-gated ion channels are concentrated.

Presynaptic terminal

The swelling at the end of an axon branch that releases neurotransmitters.

Afferent axon

An axon that brings information into a structure.

Efferent axon

An axon that carries information away from a structure.

Intrinsic neuron

A neuron whose dendrites and axon are entirely contained within a single structure of the nervous system.

Purkinje cell

A cerebellar neuron characterized by an extremely large and widely branching dendritic tree.

Glia

Supportive cells in the nervous system that interact with neurons and perform various maintenance functions.

Astrocytes

Star-shaped glia that surround synapses, synchronize closely related axons, and dilate blood vessels.

Tripartite synapse

The hypothesis that a presynaptic axon tip releases chemicals that induce neighboring astrocytes to release their own chemicals, modifying the signal to the postsynaptic cell.

Microglia

Glial cells that act as part of the immune system by removing viruses, fungi, waste, and weak synapses.

Oligodendrocytes

Glial cells in the central nervous system that build myelin sheaths surrounding axons.

Schwann cells

Glial cells in the peripheral nervous system that build myelin sheaths surrounding axons.

Radial glia

Glial cells that guide the migration of neurons, axons, and dendrites during embryonic development.

Blood-brain barrier

A mechanism of tightly joined endothelial cells along brain capillary walls that prevents harmful blood-borne chemicals from entering the brain.

Active transport

A protein-mediated process that consumes energy to move specific substances across a cell membrane into the brain.

Korsakoff's syndrome

A neurological condition characterized by severe memory loss, resulting from prolonged deficiency of vitamin B1 (thiamine).

Polarization

A difference in electrical charge between the inside and outside of a cell membrane, also known as an electrical gradient.

Resting potential

The electrical potential of a neuron's membrane when it is at rest before stimulation.

Selective permeability

The property of a cell membrane allowing certain chemicals to pass through more freely than others.

Sodium-potassium pump

A membrane protein complex that uses active transport to pump three $\text{Na}^+$ ions out for every two $\text{K}^+$ ions brought in.

Concentration gradient

The difference in the distribution of ions across the cell membrane.

Hyperpolarization

An increase in membrane polarization, making the inside of the neuron even more negative relative to the outside.

Depolarization

A reduction in membrane polarization toward zero, making the inside of the neuron less negative.

Threshold of excitation

The minimum level of depolarization required to trigger an action potential.

All-or-none law

The principle that the amplitude and speed of an action potential are independent of the strength of the initiating stimulus, provided it reaches threshold.

Voltage-gated channels

Membrane ion channels whose permeability depends on the voltage difference across the membrane.

Propagation of the action potential

The transmission of an action potential down the length of an axon without loss of amplitude.

Back-propagation

The movement of an electrical signal backward into dendrites following an action potential, facilitating structural changes in learning.

Saltatory conduction

The rapid jumping of an action potential from node to node along a myelinated axon.

Absolute refractory period

The brief period following an action potential during which the membrane cannot produce another action potential regardless of stimulus strength.

Relative refractory period

The period after the absolute refractory period when producing a second action potential requires a stronger-than-normal stimulus.

Graded potential

A membrane potential change that varies continuously in magnitude in proportion to the intensity of the stimulus.

Synapse

A specialized junction or gap between two neurons through which communication occurs.

Reflex arc

The neural circuit from sensory receptor to muscle response that produces a reflex.

Reciprocal inhibition

A reflex mechanism in which the excitation of one set of muscles is accompanied by the forced relaxation of an opposing set.

Temporal summation

The cumulative effect of repeated stimuli occurring within a brief period of time at a single synapse.

Spatial summation

The cumulative combination of synaptic inputs originating simultaneously from different spatial locations on a neuron.

Excitatory postsynaptic potential (EPSP)

A graded depolarization of the postsynaptic membrane resulting from an influx of sodium ions, bringing the neuron closer to threshold.

Inhibitory postsynaptic potential (IPSP)

A temporary hyperpolarization of the postsynaptic membrane caused by potassium exit or chloride entry, moving the cell further from threshold.

Spontaneous firing rate

A periodic generation of action potentials by a neuron without external synaptic stimulation.

Precursor

A chemical or dietary substance that the body converts into a active neurotransmitter.

Catecholamines

A group of nitrogen-containing neurotransmitters synthesized from tyrosine, including dopamine, norepinephrine, and epinephrine.

Synaptic vesicles

Tiny, spherical membrane packets located in the presynaptic terminal that store neurotransmitter molecules.

Monoamine oxidase (MAO)

An enzyme present in presynaptic terminals that breaks down excess serotonin, dopamine, and norepinephrine into inactive chemicals.

Exocytosis

The process by which neurotransmitter-filled vesicles fuse with the presynaptic membrane and burst open to release chemicals into the cleft.

Ionotropic effects

Direct, rapid, and brief synaptic actions occurring when a neurotransmitter opens or closes ligand-gated ion channels.

Glutamate

The most abundant excitatory neurotransmitter in the brain, working mainly through ionotropic receptors.

GABA

The main inhibitory neurotransmitter in the brain, which opens chloride channels to hyperpolarize postsynaptic cells.

Metabotropic effects

Slower and longer-lasting synaptic actions initiated when a neurotransmitter triggers a sequence of intracellular metabolic reactions.

Second messenger

An intracellular molecule activated by a G-protein that relays messages to influence cellular activity inside the postsynaptic cell.

Neuropeptides

Amino acid chains released mainly by dendrites and soma that act as neuromodulators with widespread, long-lasting effects.

Acetylcholinesterase

An enzyme that breaks down acetylcholine in the synaptic cleft into acetate and choline.

Reuptake

The reabsorption of released neurotransmitters by transporter proteins on the presynaptic terminal for reuse.

Autoreceptors

Receptors located on a presynaptic membrane that respond to the neuron's own neurotransmitter to provide negative feedback.

Gap junction

A low-resistance membrane contact where direct pore channels align between adjacent neurons at an electrical synapse.

Hormones

Chemical messengers secreted by glands into the bloodstream to modulate physiological functions throughout the body.