Unit 2 Biology and Psychology Vocabulary

Nervous System

The body's speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems.

Neuron

A nerve cell that acts as the basic building block of the nervous system, transmitting messages throughout the body.

Central Nervous System

The division of the nervous system consisting of the brain and spinal cord, responsible for processing information and making decisions.

Peripheral Nervous System

The sensory and motor neurons that connect the central nervous system to the rest of the body, carrying signals to and from organs and muscles.

Synapse

The tiny, fluid-filled junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron.

Neurotransmitters

Chemical messengers released by neurons that cross the synaptic gap to transmit signals to other neurons, muscles, or glands.

Axon

The lengthy fiber of a neuron that carries electrical impulses away from the cell body toward other neurons or muscles.

Dendrites

The bushy, branching extensions of a neuron that receive messages and conduct impulses toward the cell body.

Myelin Sheath

A layer of fatty tissue segmentally encasing the axon that speeds up the transmission of neural impulses.

Spinal Cord

A thick column of nerve tissue that runs from the base of the brain down the center of the back, transmitting messages between the brain and body.

Medulla

The base of the brainstem that automatically controls vital life-support functions such as heartbeat and breathing.

Pons

A brainstem structure located above the medulla that plays a key role in regulating sleep, dreaming, and facial movements.

Cerebellum

The "little brain" at the rear of the brainstem that processes sensory input, coordinates voluntary movement, and maintains balance.

Reticular Activating System

A network of nerves in the brainstem that plays a crucial role in controlling alertness, arousal, and screening incoming information.

Thalamus

The brain's sensory control center located on top of the brainstem that directs sensory messages to the cortex (except for smell).

Hypothalamus

A neural structure lying below the thalamus that directs maintenance activities (eating, drinking, body temperature) and governs the endocrine system via the pituitary gland.

Limbic System

A doughnut-shaped neural system (including the hippocampus, amygdala, and hypothalamus) associated with emotions, drives, and memory formation.

Cerebrum

The largest part of the brain, consisting of two hemispheres responsible for complex thinking, perception, memory, and voluntary behavior.

Cerebral Cortex

The intricate fabric of interconnected neural cells covering the cerebral hemispheres that serves as the body's ultimate control and processing center.

Corpus Callosum

The large band of neural fibers connecting the left and right cerebral hemispheres, allowing them to communicate with each other.

Frontal Lobe

The region of the cerebral cortex involved in high-level functions like speaking, planning, decision-making, reasoning, and muscle movements.

Temporal Lobe

The region of the cerebral cortex located above the ears that includes auditory areas, processing hearing, language interpretation, and memory.

Parietal Lobe

The region of the cerebral cortex lying at the top of the head that receives and processes sensory input for touch and body position.

Occipital Lobe

The region of the cerebral cortex located at the back of the head that receives and processes visual information from the eyes.

Pituitary Gland

The endocrine system's "master gland" located in the brain, controlled by the hypothalamus, that releases hormones affecting growth and regulating other glands.

Thyroid Gland

An endocrine gland located in the neck that produces hormones that regulate the body's metabolism, energy levels, and growth.

Adrenal Gland

A pair of endocrine glands sitting just above the kidneys that secrete hormones (like adrenaline) to help arouse the body during stress ("fight-or-flight").

Hormones

Chemical messengers manufactured by the endocrine glands that travel through the bloodstream to affect other tissues and organs.

Estrogen

A class of sex hormones found in greater amounts in females, promoting female secondary sex characteristics and regulating the menstrual cycle.

Progesterone

A hormone produced by the ovaries that prepares the uterus for pregnancy and helps maintain the early stages of gestation.

Testosterone

The primary male sex hormone produced in the testes (and small amounts in ovaries) that stimulates male sex character developments and sperm production.

Anabolic Steroids

Synthetic substances related to male sex hormones designed to promote muscle growth and enhance physical performance, often carrying health risks when abused.

Genes

The biochemical units of heredity that make up chromosomes, containing the instructions (DNA) for building proteins and driving traits.

Chromosomes

Threadlike structures made of DNA molecules that contain human genetic information (typically 23 pairs in humans).

DNA

Deoxyribonucleic acid; a complex molecule containing the genetic information that makes up chromosomes and guides biological development.

Heredity

The genetic transfer of characteristics, traits, and physical or behavioral attributes from biological parents to offspring.

Nature

The biological and genetic influences that shape an individual's development, traits, and behavior.

Nurture

The environmental, cultural, experiential, and social influences that shape an individual's development, traits, and behavior.

Kinship Studies

Research comparing individuals with varying degrees of genetic relatedness (e.g., parents, siblings, cousins) to evaluate the inheritance of behavioral traits.

Twin Studies

Research methods that compare identical twins (100% shared genes) and fraternal twins (50% shared genes) to estimate the influence of genetics versus environment on traits.