Biological Psychology: The study of how biological processes, especially those of the brain and nervous system, influence behaviors and mental processes.

Neuron: The basic unit of the nervous system; a cell that transmits electrical and chemical signals.

Dendrites: Branch-like structures on neurons that receive messages from other neurons and convey them to the cell body.

Axon: A long projection of a neuron that transmits electrical impulses to other neurons, muscles, or glands.

Myelin Sheath: A fatty layer that insulates the axon, speeding up the transmission of electrical signals.

Action Potential: A brief electrical charge that travels down the axon, enabling the neuron to transmit a signal.

Refractory Period: The short period after an action potential during which a neuron cannot fire again.

Threshold: The minimum level of stimulation required to trigger an action potential in a neuron.

All-or-None Response: The principle that a neuron either fires completely or does not fire at all, regardless of the strength of the stimulus above the threshold.

Synapse: The junction between two neurons where communication occurs via neurotransmitters.

Neurotransmitters: Chemicals released by neurons that transmit signals across the synapse to another neuron or target cell.

Reuptake: The process by which neurotransmitters are reabsorbed by the sending neuron after signaling.

Endorphins: Neurotransmitters that act as natural painkillers and mood elevators.

Agonist: A chemical or drug that mimics the action of a neurotransmitter by binding to its receptor.

Antagonist: A chemical or drug that blocks the action of a neurotransmitter by binding to its receptor without activating it.

Nervous System: The body's electrochemical communication network, consisting of the brain, spinal cord, and nerves.

Central Nervous System (CNS): The part of the nervous system made up of the brain and spinal cord, responsible for processing and sending out information.

Peripheral Nervous System (PNS): The sensory and motor neurons that connect the CNS to the rest of the body.

Nerves: Bundles of axons that transmit information to and from the brain and spinal cord.

Sensory (Afferent) Neurons: Neurons that carry incoming information from sensory receptors to the CNS.

Motor (Efferent) Neurons: Neurons that carry outgoing information from the CNS to muscles and glands.

Interneurons: Neurons that process information within the CNS, connecting sensory and motor pathways.

Somatic Nervous System: The division of the PNS that controls voluntary movement of skeletal muscles.

Autonomic Nervous System: The part of the PNS that regulates involuntary body functions, such as heartbeat and digestion.

Parasympathetic Nervous System: A division of the autonomic nervous system that calms the body and conserves energy.

Reflex: A simple, automatic response to a sensory stimulus, usually controlled by the spinal cord.

Endocrine System: The body’s chemical communication system, consisting of glands that release hormones into the bloodstream.

Hormones: Chemical messengers secreted by endocrine glands that regulate various body functions.

Adrenal Glands: Glands located above the kidneys that produce hormones such as adrenaline, which helps the body respond to stress.

Pituitary Gland: The "master gland" that regulates other endocrine glands and controls growth and development.

Lesion: Any damage or abnormal change in tissue, particularly brain tissue, often used in research to study brain function.

Electroencephalogram (EEG): A test that measures electrical activity in the brain using electrodes placed on the scalp.

CT (Computed Tomography) Scan: A brain imaging technique that uses X-rays to create detailed pictures of brain structure.

PET (Positron Emission Tomography) Scan: A brain imaging technique that shows brain activity by detecting radioactive glucose.

MRI (Magnetic Resonance Imaging): A technique that uses magnetic fields and radio waves to produce detailed images of the brain’s soft tissues.

Brainstem: The oldest part of the brain, responsible for controlling vital functions such as heart rate and breathing.

Medulla: The base of the brainstem that controls automatic functions such as heartbeat and breathing.

Thalamus: The brain's relay center, which directs sensory information to the appropriate areas of the cerebral cortex.

Reticular Formation: A network of neurons that runs through the brainstem and plays a key role in arousal and attention.

Cerebellum: A brain structure that helps coordinate voluntary movements and balance.

Limbic System: A group of structures in the brain involved in emotions, memory, and motivation.

Amygdala: A structure in the limbic system involved in processing emotions, especially fear and aggression.

Hypothalamus: A brain structure that regulates bodily functions such as hunger, thirst, temperature, and hormones.

Cerebral Cortex: The outermost layer of the brain, involved in complex cognitive functions such as thinking, planning, and perception.

Glial Cells: Support cells in the nervous system that protect and nourish neurons.

Frontal Lobes: The part of the brain involved in decision-making, problem-solving, and controlling voluntary movements.

Parietal Lobes: Brain areas that process sensory input related to touch and body position.

Occipital Lobes: The portion of the brain that processes visual information.

Temporal Lobes: The part of the brain involved in processing auditory information and memory.

Motor Cortex: A region of the frontal lobe responsible for voluntary movement.

Somatosensory Cortex: A part of the parietal lobe that processes touch, temperature, and body position.

Association Areas: Areas of the cerebral cortex involved in higher-level processes such as learning, memory, and interpreting sensory information.

Plasticity: The brain’s ability to change by reorganizing itself after damage or by forming new connections.

Neurogenesis: The formation of new neurons, which can occur in certain areas of the brain throughout life.

Corpus Callosum: The large band of neural fibers connecting the two hemispheres of the brain and allowing them to communicate.

Split Brain: A condition in which the corpus callosum is severed, resulting in the disconnection of the brain's hemispheres.

Consciousness: Awareness of ourselves and our environment, encompassing thoughts, sensations, and perceptions.

Cognitive Neuroscience: The study of brain activity linked to mental processes such as perception, memory, and decision-making.

Dual Processing: The principle that information is simultaneously processed on separate conscious and unconscious tracks.

Behavior Genetics: The study of how genetic and environmental factors influence behavior.

Environment: All external influences, from prenatal development to cultural and social factors, that affect behavior.

Chromosomes: Structures made of DNA molecules that contain genes.

DNA: The molecule that carries genetic instructions for the development, functioning, and reproduction of all living organisms.

Genes: Units of heredity made of DNA that determine individual traits.

Genome: The complete set of genetic information in an organism, including all of its genes.

Identical Twins: Twins who develop from a single fertilized egg and share the same genetic makeup.

Fraternal Twins: Twins who develop from two separate eggs and share about 50% of their genetic material.

Molecular Genetics: The field of biology that studies the molecular structure and function of genes.

Heritability: The proportion of variation among individuals that can be attributed to genetic factors.

Interaction: The interplay between genes and environment, where both influence the development of traits and behavior.

Epigenetics: The study of how environmental factors can change gene expression without altering the DNA sequence.

Evolutionary Psychology: The study of how natural selection has shaped behavior and mental processes to enhance survival.

Natural Selection: The process by which traits that enhance survival and reproduction become more common in successive generations.

Mutation: A change in the DNA sequence that can lead to new traits or variations within a species.