Biological Psychology – Nerve Cells and Nerve Impulses

Vocabulary flashcards covering key terms from the lecture on nerve cells and nerve impulses.

Neuroscience

The study of the nervous system.

Biological psychology (Behavioral neuroscience)

The study of the biological bases of psychological processes and behavior.

Dualism

The view that humans have a nonmaterial soul and a material body, with the soul influencing behavior at a contact point (e.g., the pineal gland).

Reductionism

A method that breaks a system into smaller parts to understand it.

Levels of analysis

The scope of an experimental approach, from social interactions to molecular processes.

Ontology/Ontogeny

Ontogeny: the change in an individual during its lifetime.

Neuron

A brain cell that receives and transmits information.

Glia

Non-neuronal cells that support and modulate neurons.

Dendrites

Branching fibers that receive information; surface area increases with branching.

Dendritic spines

Small protrusions on dendrites that increase synaptic contact surface.

Soma (cell body)

Metabolic center of the neuron containing the nucleus and organelles.

Axon

Long fiber that transmits nerve impulses away from the soma.

Myelin sheath

Insulating layer around some axons, formed by glia, increasing conduction speed.

Nodes of Ranvier

Gaps in the myelin sheath where action potentials are regenerated.

Presynaptic terminals

End points of an axon that release neurotransmitters into the synapse.

Axodendritic synapse

A synapse from an axon to a dendrite.

Axosomatic synapse

A synapse from an axon to the soma.

Axoaxonic synapse

A synapse from an axon to another axon.

Afferent

Nerve fibers that bring information into a structure.

Efferent

Nerve fibers that carry information out of a structure.

Interneurons

Neurons that connect other neurons within a region (intrinsic).

Purkinje cells

Large, highly branched neurons in the cerebellar cortex.

Astrocytes

Glial cells that help synchronize activity and regulate neurotransmitters around synapses.

Microglia

Glial cells that remove waste material, viruses, and fungi from the brain.

Oligodendrocytes

CNS glia that form the myelin sheath around axons.

Schwann cells

PNS glia that form the myelin sheath around axons.

Radial glia

Glial cells that guide neuron migration and axon/dendrite growth during development.

Blood-brain barrier

Barrier surrounding the brain that blocks most chemicals from entering; formed by endothelial cells.

Endothelial cells

Cells lining blood vessels; contribute to the blood-brain barrier.

Active transport

Energy-dependent transport of substances from the blood into the brain (e.g., glucose, amino acids).

Glucose

Primary energy source for neurons.

Thiamine

Vitamin B1 needed to use glucose.

Korsakoff's syndrome

Memory impairment caused by thiamine deficiency.

Resting potential

Baseline electrical charge across the neuron's membrane (about -70 mV).

Depolarization

Decrease in polarization toward zero; brings the neuron closer to firing.

Hyperpolarization

Increase in polarization, making the inside more negative.

Threshold of excitation

Level of stimulation needed to trigger an action potential.

Voltage-activated channels

Ion channels whose permeability depends on membrane potential; mainly Na+ and K+ channels.

Action potential

Brief reversal of membrane potential that propagates along the axon.

All-or-none law

Amplitude and speed of an action potential are independent of stimulus strength.

Saltatory conduction

Conduction of the action potential between nodes of Ranvier in myelinated axons; faster and energy-efficient.

Refractory period

Time after an action potential when another cannot be produced (absolute and relative).

Absolute refractory period

Phase when no action potential can be produced.

Relative refractory period

Phase when a stronger-than-usual stimulus is needed to trigger an action potential.

Sodium-potassium pump

Active transporter that moves Na+ out and K+ in to maintain ionic gradients.

Ion channels

Protein pathways that allow specific ions to cross the membrane.

Novocain

Local anesthetic that blocks sodium channels to prevent action potentials.

Xylocaine

Local anesthetic that blocks sodium channels to prevent action potentials.

Multiple sclerosis

Disease in which myelin sheath is damaged, slowing or blocking conduction.

Synapse

Junction where communication occurs between neurons via neurotransmitters.