Chapter 2: The Biological Perspective Flashcards

Vocabulary flashcards covering key definitions, anatomical structures, neurotransmitters, and physiological concepts from Chapter 2: The Biological Perspective.

Neuroscience

A branch of the life sciences that deals with the structure and functioning of the brain and the neurons, nerves, and nervous tissue that form the nervous system.

Biological Psychology

Also known as behavioral neuroscience; a branch of neuroscience that focuses on the biological bases of psychological processes, behavior, and learning.

Santiago Ramón y Cajal

A doctor who, in 1887, studied slides of brain tissue and first theorized that the nervous system was made up of individual cells.

Neuron

The basic cell that makes up the nervous system and receives and sends messages within that system.

Dendrites

Branch-like structures of a neuron that receive messages from other cells.

Soma

The cell body of the neuron that contains the nucleus and keeps the entire cell alive and functioning.

Axon

A fiber attached to the soma that carries neural messages out to other cells.

Axon Terminals

Structures located at the end of the axon that communicate with other nerve cells; also called presynaptic terminals, terminal buttons, or synaptic knobs.

Glial Cells

Primary cells in the nervous system that provide support, nutrients, cleanup, insulation, and maintenance of homeostasis for neurons.

Myelin

A fatty substance that wraps around axons to insulate them and help electrical signals travel faster.

Oligodendrocytes

A type of glial cell that produces myelin in the Central Nervous System (CNS).

Schwann Cells

A type of glial cell that produces myelin in the Peripheral Nervous System (PNS).

Tracts

Bundles of myelin-coated axons in the Central Nervous System (CNS).

Nerves

Bundles of axons in the Peripheral Nervous System (PNS).

Nodes

Small spaces on the axon not covered by myelin where ion channels are concentrated.

Saltatory Conduction

The process along a myelinated axon where an electrical impulse appears to jump from node to node, speeding up conduction velocity.

Multiple Sclerosis (MS)

An autoimmune disease in which the myelin sheath is destroyed, leading to diminished or complete loss of neural functioning.

Resting Potential

The state of a neuron when it is not firing, characterized by a mostly negative electrical charge inside and a mostly positive charge outside.

Action Potential

The release of an electrical impulse along the axon that occurs when the electrical potential reverses after reaching the threshold.

Depolarization

The phase during an action potential when sodium channels open and positive sodium ions ($Na^+$) rush into the cell, making the inside positive.

Repolarization

The phase following an action potential where sodium channels close and potassium channels open, letting positive potassium ions ($K^+$) exit to restore a negative internal charge.

Hyperpolarization

A brief period after repolarization where the inside of the cell becomes temporarily more negative than its normal resting potential level.

All-or-None Law

The principle stating that a neuron either fires completely at full strength or does not fire at all once threshold is reached.

Synapse

The microscopic fluid-filled space between the axon terminal of one cell and the dendrites or soma of another cell across which signals travel.

Presynaptic Membrane

The membrane located at the end of the sending axon terminal that contains synaptic vesicles and releases neurotransmitters.

Postsynaptic Membrane

The membrane of the receiving cell that contains receptor sites and ion channels.

Synaptic Vesicles

Small sac-like structures inside the axon terminal that contain chemical messengers known as neurotransmitters.

Neurotransmitters

Chemical messengers stored in synaptic vesicles that transmit signals across the synaptic gap to activate or inhibit receiving cells.

Receptor Sites

Proteins on the surface of the postsynaptic cell shaped to fit only specific neurotransmitter molecules, functioning like a lock and key.

Excitatory Effect

A neurotransmitter effect that turns the receiving cell on and encourages it to fire.

Inhibitory Effect

A neurotransmitter effect that turns the receiving cell off and prevents or reduces its firing.

Agonists

Chemical substances that mimic or enhance the effects of a neurotransmitter on receptor sites.

Antagonists

Chemical substances that block or reduce a cell's response to the action of neurotransmitters or other chemicals.

Acetylcholine (ACh)

An excitatory or inhibitory neurotransmitter involved in arousal, attention, memory, and muscle contractions.

Norepinephrine (NE)

A mainly excitatory neurotransmitter involved in arousal and mood regulation.

Dopamine (DA)

An excitatory or inhibitory neurotransmitter involved in control of movement and sensations of pleasure.

Serotonin (5-HT)

An excitatory or inhibitory neurotransmitter involved in sleep, mood, anxiety, and appetite.

Gaba-aminobutyric acid (GABA)

The major inhibitory neurotransmitter in the brain; involved in sleep and inhibiting movement.

Glutamate

The major excitatory neurotransmitter in the brain; involved in learning, memory formation, nervous system development, and synaptic plasticity.

Endorphins

Inhibitory neural regulators involved in pain relief.

Reuptake

The process by which neurotransmitters are taken back into the presynaptic neuron to clear the synaptic gap and repackage them into vesicles.

Enzymatic Degradation

A cleanup process in which specific enzymes rapidly break down neurotransmitters (such as acetylcholine) in the synaptic gap.

SSRIs (Selective Serotonin Reuptake Inhibitors)

Drugs used to treat depression, anxiety, and OCD by blocking the reuptake of serotonin, making more serotonin available in the synapse.

Central Nervous System (CNS)

The part of the nervous system consisting of the brain and spinal cord.

Spinal Cord

A long bundle of neurons that carries messages between the body and brain and is responsible for fast, lifesaving reflexes.

Sensory Neurons

Also called afferent neurons; unipolar neurons that carry information from the senses to the Central Nervous System.

Motor Neurons

Also called efferent neurons; multipolar neurons that carry instructions from the Central Nervous System to the muscles and glands of the body.

Interneurons

Bipolar neurons found in the center of the spinal cord and brain that connect sensory input to motor output and make up the bulk of neurons in the brain.

Reflex Arc

The neural pathway consisting of sensory neurons connecting to interneurons and motor neurons that results in an involuntary reflex action.

Neuroplasticity

The ability of brain cells to constantly change both their structure and function in response to experience or trauma.

Neurogenesis

The formation of new neurons.

Peripheral Nervous System (PNS)

All nerves and neurons not contained within the brain and spinal cord that extend through the rest of the body.

Somatic Nervous System

A division of the PNS consisting of sensory pathways and motor pathways that control voluntary skeletal muscles.

Autonomic Nervous System (ANS)

A division of the PNS consisting of nerves that automatically regulate involuntary muscles, internal organs, and glands.

Sympathetic Division

The fight-or-flight division of the ANS responsible for reacting to stressful events and driving bodily arousal.

Parasympathetic Division

The part of the ANS that restores the body to normal functioning after arousal and maintains day-to-day operations of organs and glands.

Endocrine Glands

Glands that secrete chemicals called hormones directly into the bloodstream.

Hormones

Chemical messengers released into the bloodstream by endocrine glands to affect target organs throughout the body.

Pituitary Gland

Located in the brain, it is known as the master gland because it secretes human growth hormone and controls other endocrine glands.

Pineal Gland

An endocrine gland located near the base of the cerebrum that secretes melatonin.

Thyroid Gland

An endocrine gland located in the neck that secretes hormones regulating metabolism.

Pancreas

An endocrine gland responsible for controlling levels of sugar in the blood.

Gonads

The sex glands (ovaries in females, testes in males) that secrete hormones regulating sexual development, behavior, and reproduction.

Adrenal Glands

Endocrine glands located on top of each kidney that secrete over thirty stress-handling hormones and secondary sex hormones.

Lesioning Studies

A study technique involving insertion of a thin insulated wire into the brain through which an electrical current destroys targeted brain cells.

Computed Tomography (CT)

A noninvasive brain-imaging method using computer-controlled X-rays to generate structural images of the brain.

Magnetic Resonance Imaging (MRI)

A noninvasive brain-imaging method using radio waves and magnetic fields to produce detailed structural pictures of the brain.

Electroencephalogram (EEG)

A brain mapping technique using scalp electrodes to record the brain's electrical activity with high temporal resolution.

Positron Emission Tomography (PET)

A functional brain-imaging method that injects a radioactive tracer bound to glucose to track cellular activity in the brain.

Functional MRI (fMRI)

A functional brain-imaging technique that tracks changes in blood oxygen levels to map active brain areas.

Functional Near-Infrared Spectroscopy (fNIRS)

A functional imaging technique that uses near-infrared light to measure cortical blood oxygenation.

Medulla

The lowest part of the hindbrain at the top of the spinal cord responsible for life-sustaining functions such as breathing, swallowing, and heart rate.

Pons

A swelling above the medulla connecting upper and lower brain areas; plays a role in sleep, dreaming, left-right body coordination, and arousal.

Reticular Formation (RF)

A network of neurons running through the medulla and pons responsible for selective attention and arousal.

Cerebellum

A structure located at the back of the hindbrain behind the pons that controls and coordinates involuntary, rapid, fine motor movements.

Limbic System

A group of subcortical brain structures involved in emotions, memory, learning, and motivation.

Thalamus

A limbic structure located in the center of the brain that relays sensory information from lower centers to the appropriate areas of the cerebral cortex.

Hypothalamus

A limbic structure below the thalamus that regulates motivational behaviors such as sleep, hunger, thirst, aggression, and sexual drive.

Hippocampus

A curved structure within each temporal lobe responsible for forming long-term memories and storing spatial location memories.

Amygdala

A limbic structure near the hippocampus responsible for fear responses, fear memory, motivation, and interpreting emotional expressions.

Cingulate Cortex

The primary cortical component of the limbic system, involved in cognitive and emotional processing.

Cortex

The outermost layer of densely packed neurons covering the brain, responsible for higher thought processes and sensory interpretation.

Corpus Callosum

A thick band of nerve fibers connecting the left and right cerebral hemispheres.

Corticalization

The wrinkling of the cortex that allows a larger amount of cortical area to fit inside the skull, increasing processing complexity.

Occipital Lobe

The lobe located at the rear and bottom of each cerebral hemisphere, containing the primary visual cortex and visual association cortex.

Parietal Lobes

Lobes at the top and back of each cerebral hemisphere containing the somatosensory cortex for touch, taste, temperature, and body position sensations.

Temporal Lobes

Lobes located behind the temples containing the primary auditory cortex and auditory association cortex responsible for hearing and meaningful speech.

Frontal Lobes

Lobes located at the front and top of the brain responsible for higher mental processes, decision making, fluent speech production, and motor control.

Motor Cortex

A strip located at the back of the frontal lobe that sends motor commands to control voluntary body muscles.

Somatosensory Cortex

An area running down the front of the parietal lobes that receives input from body position receptors and skin sensors for touch, temperature, and taste.

Association Areas

Regions within each cerebral lobe responsible for coordination, interpretation of information, and higher mental processing by connecting sensory input to stored knowledge.

Broca's Aphasia

A condition caused by damage to Broca's area in the left frontal lobe, causing affected individuals to speak haltingly and mispronounce words.

Wernicke's Aphasia

A condition caused by damage to Wernicke's area in the left temporal lobe, resulting in an inability to comprehend or produce meaningful spoken language.

Spatial Neglect

A condition resulting from damage to association areas of the right hemisphere that causes a person to ignore objects or body parts in the left visual field.

Cerebrum

The upper part of the brain consisting of the two cerebral hemispheres and the structures connecting them.

Split-Brain Research

The study of patients with a severed corpus callosum, demonstrating functional specialization between the left and right hemispheres.

Bálint's Syndrome

A visual and perceptual disorder characterized by optic ataxia, oculomotor apraxia, and simultanagnosia.

Epigenetics

The study of interactions between genes and environmental factors (such as diet and surroundings) that influence gene activity.

Mirror Neurons

Neurons that fire both when performing an action and when observing that same action performed by another.

Olfactory Bulbs

Two bulb-like projections located above the sinus cavity and below the frontal lobes that receive input from olfactory receptor cells.