Human Biology Definitions Y10

Definitions for essential terms for year 10 human biology.

Cell

The basic unit of life.

Tissue

A group of similar cells working together.

Organ

A structure made of different tissues that perform a specific function.

Organ System

A group of organs working together to carry out a major body function (movement)

Homeostasis

The maintenance of a stable internal environment.

Mitosis

Cell division producing two identical cells

Artery

Blood vessel carrying blood away from the heart

Heart

Muscular organ that pumps blood around the body

Vein

Blood vessel carrying blood to the heart.

Capillary

Tiny blood vessel where exchange of substance occurs

Red Blood Cell

Cell that carries oxygen using haemoglobin. Found throughout the entire body.

White Blood Cell

Cell that helps fight disease and infections. Found and produced in the marrow of bones.

Respiration

Release of energy from glucose in cells.

Alveoli

Tiny air sacs where gas exchange occurs.

Oxygen

Gas needed for cellular respiration and what we need to live.

Carbon Dioxide

Waste gas produced during respiration.

Digestive System

Breaks down food and absorbs nutrients (stomach)

Enzyme

Protein that speeds up the rate of reaction in chemical reactions.

Nutrient

Substance needed for growth and survival.

Central Nervous System

The complex of nerve tissues that controls the activities of the body (brain and spinal cord)

Peripheral Nervous System

The nervous system outside of the brain and spinal cord (cranial and spinal nerves)

Autonomic Nervous System

The part of the nervous system that is responsible for control of the bodily functions not consciously directed (heart)

Somatic Nervous System

Connects the central nervous system to the body’s muscle and skin (voluntary skeletal muscles).

Neuron

Nerve cell that carries messages throughout the body. The gaps in between neurons are known as the synapse.

Hormone

Chemical messenger carried within the blood of a human.

Endocrine System

System of glands that produce hormones (thyroid, pituitary)

Reproduction

The process of producing offspring, either sexually or asexually.

Fertilisation

Joining of sperm and egg cells in one’s body.

Immune System

The body’s system of defence against disease and pathogens.

Pathogen

Disease-causing microorganisms (bacteria)

Vaccine

Substance that stimulates immunity to a pathogen or disease.