Unit 1: Biological Basis of Behavior

Comprehensive vocabulary flashcards covering the biological perspective, neural communication, neurotransmitters, nervous system divisions, endocrine functions, brain structures, and cortical localization based on the lecture notes.

Biological Perspective

A psychological approach where biopsychologists study the link between biological factors (such as genes, neurons, and hormones) and psychological mental processes.

Evolutionary Perspective

A perspective that studies how behavior and the mind have evolved over time through natural selection, where inherited traits that aid survival are passed down to future generations.

Identical Twins (Monozygotic)

Twins that develop from a single fertilized egg and share the exact same DNA, studied to understand the influence of nature versus nurture.

Fraternal Twins (Dizygotic)

Twins that develop from separate fertilized eggs and are genetically no more similar than regular siblings.

Neuron

An individual nerve cell that runs throughout the entire brain and body; the human brain alone is estimated to contain approximately $68\text{ billion}$ of them.

Dendrite

The branching structure at the beginning of a neuron where an electrical impulse starts and where incoming messages are received.

Axon

The long, extended part of a neuron that carries electrical information from the beginning to the end of the cell.

Terminal Endings / Buttons

The structures located at the end of a neuron that store and release neurotransmitters across the synapse.

Myelin Sheath

A fatty coating that insulates some axons and speeds up the transmission of neural impulses; a lack or degradation of this coating causes multiple sclerosis.

Neural Impulse Speed

The velocity at which an electrical impulse travels down a neuron, ranging from about $2\text{ to }200\,\text{MPH}$.

Resting Potential

The electrical state of a neuron when it is at rest, characterized by a slightly negative interior charge.

Threshold

The minimum level of stimulation required to trigger an action potential and cause a neuron to fire.

All-or-None Response

The principle that a neuron either fires completely when the threshold is reached or does not fire at all, with no partial firing.

Action Potential

The firing of a neuron that produces a brief electrical charge traveling down the axon from the beginning of the cell to the end like a falling domino.

Depolarization

The shift in electrical charge within a neuron during an action potential, bringing the cell's internal charge closer to zero.

Synapse

The microscopic physical space between the terminal ending of one neuron and the dendrites of an adjacent receiving neuron.

Refractory Period

A resting phase immediately following an action potential during which a neuron cannot fire again until it resets.

Neurotransmitters

Chemical messengers (numbering over $100$ types) that are released into the synaptic cleft to transmit signals between neurons.

Reuptake

The process by which neurotransmitters that have detached from the receiving neuron's receptor sites are reabsorbed back into the sending neuron.

Excitatory Signals

Neural signals that exceed the stimulation threshold and instruct the next neuron to generate an action potential.

Inhibitory Signals

Neural signals that prevent the cell from reaching the threshold or transmit messages that actively block an action potential from occurring.

Blood-Brain Barrier

A physiological barrier that circulating psychoactive drugs must cross in order to exert their effects on brain function.

Agonist Drugs

Substances that mimic the effects of specific neurotransmitters to trigger an excitatory response, such as ecstasy mimicking serotonin, dopamine, and norepinephrine.

Antagonist Drugs

Substances that block or inhibit neurotransmitter activity, such as botox blocking acetylcholine or novocaine blocking pain messages.

Selective Serotonin Reuptake Inhibitors (SSRIs)

Antidepressant medications (such as Prozac, Zoloft, Paxil, and Lexapro) that treat depression by blocking the reabsorption of serotonin in the synapse.

Sensory Neurons

Neurons that convey incoming sensory information from sensory receptors throughout the body to the brain and spinal cord.

Motor Neurons

Neurons that carry outgoing motor instructions from the brain and spinal cord to muscles and glands in the body.

Interneurons

Internal communication neurons located entirely within the brain and spinal cord (Central Nervous System).

Reflex emergency

sensory neuron (touch something hot) sends message to…

interneuron (brain/spinal cord) recognizes emergecy and activates…

motor neurons for movement before it tells the brain

Central Nervous System (CNS)

The primary division of the nervous system composed exclusively of the interneurons located in the brain and spinal cord.

Peripheral Nervous System (PNS)

The division of the nervous system consisting of all sensory and motor neurons outside the central brain and spinal cord, subdivided into somatic and autonomic branches.

Somatic Nervous System

The branch of the Peripheral Nervous System responsible for controlling voluntary skeletal muscle movements.

Autonomic Nervous System

The division of the Peripheral Nervous System that automatically regulates involuntary bodily functions, consisting of sympathetic and parasympathetic divisions.

Sympathetic Nervous System

The 'fight-or-flight' accelerator division of the autonomic system that dilates pupils, rushes blood to major muscles, increases sweating, speeds breathing, and halts digestion.

Parasympathetic Nervous System

The 'brake pedal' division of the autonomic nervous system that calms the body down after stress and restores baseline functioning.

Endocrine System

The body's secondary, slower-acting chemical communication system, operated by glands that secrete hormones directly into the bloodstream.

Hormones

Chemical messengers produced by endocrine glands that travel through the bloodstream; they take longer to deliver messages than neurons, but their effects persist longer.

Pituitary Gland

The 'master gland' of the endocrine system, controlled by the hypothalamus, which secretes growth hormones and directs the hormone production of other endocrine glands.

Electroencephalogram (EEG)

A brain imaging technique that measures and records patterns of electrical activity across the surface of the brain.

Functional Magnetic Resonance Imaging (fMRI)

A neuroimaging scan that detects blood flow changes to display both anatomical structure and active brain function simultaneously.

Medulla

The lower portion of the brainstem responsible for regulating critical, involuntary autonomic survival functions including blood pressure, heartbeat, and breathing.

Thalamus

The sensory switchboard of the brain that collects incoming information from all senses (except smell) and directs it to the appropriate sensory cortex.

Reticular Activating System (RAS)

A network of neurons running from the spinal cord through the brainstem that controls physiological arousal, sleep, and wakefulness.

Cerebellum

The brain structure located behind the brainstem that governs balance, bodily coordination, and fine muscle motor movements.

Limbic System

A group of interconnected structures surrounding the brainstem (including the hypothalamus, amygdala, and hippocampus) involved in emotion and memory processing.

Hypothalamus

A limbic structure below the thalamus that regulates body temperature, sexual arousal, hunger, thirst, fight-or-flight, the reward/pleasure center, and the endocrine system.

Amygdala

A primitive emotion center in the limbic system that processes survival emotions, particularly fear and aggression.

Hippocampus

A key limbic structure essential for processing and encoding new memories into long-term storage.

Cerebral Cortex

The outer, visible surface of the brain consisting of a thin, densely packed layer of neurons responsible for high-level information processing and storage.

Brain Lateralization

The specialized division of labor between the two cerebral hemispheres, where each hemisphere manages distinct cognitive functions and controls the opposite side of the body.

Left Hemisphere

The cerebral hemisphere controlling the right side of the body; specializes in language, logic, sequential tasks, parts, objective facts, spelling, and algebra.

Right Hemisphere

The cerebral hemisphere controlling the left side of the body; specializes in spatial reasoning, facial recognition, music, art, intuition, wholes, subjective thinking, and geometry.

Occipital Lobe

The lobe situated at the back of the cerebral cortex primarily dedicated to visual processing.

Temporal Lobe

The cortical lobe located on the sides of the head that processes auditory information, contains facial recognition areas, and houses Wernicke's area in the left hemisphere.

Wernicke's Area

A language center located exclusively in the left temporal lobe that interprets written and spoken words; damage causes Wernicke's aphasia (loss of language comprehension).

Parietal Lobe

The lobe at the crown of the head responsible for mathematical and spatial reasoning; houses the somatosensory cortex along its anterior border.

Somatosensory Cortex

A cortical strip located at the front edge of the parietal lobe that registers incoming physical touch and sensory sensations from the body.

Frontal Lobe

The last brain region to fully develop (by the mid-$20\text{s}$); controls abstract thought, judgment, planning, predicting consequences, emotional control, and core personality.

Phineas Gage

An $1848$ case study involving severe prefrontal cortex damage resulting in profound personality changes, loss of social inhibitions, and impulsivity without loss of speech or walking.

Motor Cortex

A strip located at the rear boundary of the frontal lobe that initiates and directs voluntary muscle movement across the body.

Broca's Area

A language region located in the left frontal lobe controlling the muscle movements necessary for speech production; damage causes Broca's aphasia.

Brain Plasticity

The brain's ability to adapt, reorganize, and grow new dendritic neural connections to compensate for injury, occurring more rapidly in young children.

Corpus Callosum

A wide band of nerve fibers connecting the left and right cerebral hemispheres, which when surgically severed halts the spread of severe epileptic seizures.

Acetylcholine (ACh)

A neurotransmitter that facilitates muscle movement, learning, and memory; deficiencies are linked to Alzheimer's disease and Myasthenia Gravis.

Dopamine

A neurotransmitter regulating pleasure, reward, movement, and attention; an excess is linked to schizophrenia, while a deficiency causes Parkinson's disease.

Serotonin

A neurotransmitter regulating mood, hunger, sleep, and physiological arousal; inadequate levels in the brain are linked to depression.

Norepinephrine

A neurotransmitter that boosts alertness, arousal, concentration, and fight-or-flight responses; insufficient levels are associated with low mood.

GABA (Gamma-Aminobutyric Acid)

The primary inhibitory neurotransmitter that promotes calm and reduces anxiety; deficits cause tremors, insomnia, anxiety, and seizures.

Glutamate

The primary excitatory neurotransmitter involved in memory; an excess overstimulates the central nervous system, leading to migraines and seizures.

Endorphins

Endogenous neurotransmitters that provide natural pain relief and sensations of euphoria; artificial opiates mimic them, shutting down the body's natural production.

Substance P

A neurotransmitter involved in pain perception and immune responses; elevated levels are linked to chronic pain.