IBDP Biology C3.1 Integration of Body Systems SL & HL vocabulary

Cells

the fundamental, basic unit of all living organisms.

Multicellular

an organism composed of many cells.

Tissues

a group of similar cells that work together to perform a specific function.

Organs

a structure made up of different tissues working together to perform a specific function.

Organ Systems

a collection of related organs that work together to perform a specific function or a set of functions within the body.

Emergent Properties

characteristics or behaviours that arise from the interactions of the components of a system, and are not present in the individual components themselves.

Nervous System

a network of nerve cells (neurones) that communicate rapidly using electrical impulses to control and coordinate the body's functions.

Endocrine System

a network of glands and organs that produce and release hormones, which act as chemical messengers to regulate various bodily functions.

Blood Plasma

the straw-colored, liquid part of blood in which blood cells are suspended.

Cerebral Cortex (Cerebrum)

the outermost layer of the brain, responsible for higher-level thinking, conscious thought, and complex functions like language, memory, and decision-making.

Cerebellum

the part of the brain located at the back of the head, between the cerebrum and the brainstem.

Medulla Oblongata

the lowest part of the brainstem, located between the brain and the spinal cord.

Hypothalamus

The part of the brain that detects changes in blood temperature and water concentration.

Pituitary Gland

a small, pea-sized gland located at the base of the brain, often called the 'master gland' because it produces hormones that regulate other glands and processes throughout the body.

Central Nervous System

the brain and spinal cord, which act as the body's central processing and coordinating unit.

Brain

the central control organ of the nervous system, responsible for processing information, coordinating complex behaviors, and controlling the body's functions.

Voluntary Control

the conscious and intentional ability to initiate and regulate muscle movements.

Involuntary Control

automatic responses that are not under conscious control.

Unconscious Processes

automatic, involuntary functions or actions the body performs without conscious thought or control.

Sensory Neurons

a nerve cell that transmits information from sensory receptors to the central nervous system (CNS), which includes the brain and spinal cord.

Interneurons

the central nodes of neural circuits, enabling communication between sensory or motor neurons and the central nervous system (CNS).

Motor Neurons

a nerve cell in the central nervous system (CNS) that transmits signals from the brain or spinal cord to muscles or glands, resulting in a response, often movement.

Nerves

a bundle of nerve cells, also called neurons, that transmit electrical signals between different parts of the body, including the brain, spinal cord, and other organs.

Pain Reflex Arc

the pathway followed by nerve impulses when a painful stimulus triggers an automatic, involuntary response, such as pulling your hand away from a hot object.

Effector

an organ, tissue, or cell that produces a response to a stimulus.

Circadian Rhythms

an organism's natural internal clock that regulates sleep-wake cycles and various other biological processes over a 24-hour period.

Melatonin

a hormone produced in the pineal gland that helps regulate the sleep-wake cycle, also known as the circadian rhythm.

Pineal Gland

a small, pinecone-shaped endocrine gland located in the brain, specifically in the epithalamus.

Epinephrine / Adrenaline

a hormone secreted by the adrenal glands in response to stress or danger.

Adrenal Glands

small, triangle-shaped endocrine glands located on top of each kidney.

Baroreceptors

specialized nerve endings, also known as mechanoreceptors, that detect changes in blood pressure and blood volume.

Chemoreceptors

are specialised sensory receptors that detect changes in the chemical composition of a substance, typically in the blood or environment.

pH

a measure of the acidity or alkalinity (basicity) of a solution, specifically the concentration of hydrogen ions (H+) in that solution.

Ventilation

the process of breathing, which involves the mechanical movement of air into and out of the lungs.

Cardiovascular Control Centre

the process of breathing, which involves the mechanical movement of air into and out of the lungs.

Respiratory Control Centre

the part of the brainstem, specifically in the medulla oblongata, that controls breathing rate and depth.

Digestive System

a group of organs working together to break down food into smaller molecules that the body can absorb and use for energy, growth, and repair.

Peristalsis

the wave-like muscle contractions that move food through the digestive tract.

Autonomic Nervous System

the part of the peripheral nervous system that controls involuntary bodily functions, like heart rate, breathing, and digestion.

Enteric Nervous System

a complex network of nerve cells, also known as the 'second brain,' that controls the gastrointestinal tract.

Swallowing

the process of moving food or drink from the mouth, through the pharynx (throat), and down the esophagus to the stomach.

Egestion

the process of removing undigested food waste (faeces) from the body through the anus.