Year 8 Science - Body Systems

Body System

Groups of organs that work together to perform a function

Organ

a structure in the body that is composed of different kinds of tissue that work together

Tissue

a group of similar cells that work together to perform a specific job in the body

Digestive System

the system that breaks down food into small nutrient molecules

Circulatory System

the system that moves blood around the body

Respiratory System

the system responsible for getting oxygen into the blood and removing carbon dioxide from the body.

Reproductive System

the system that is involved in producing offspring

Oesophagus

the tube that takes the food to your stomach from your mouth

Stomach

sac-like organ that chemically and mechanically digests food received from the esophagus

Small Intestine

The organ that is mainly responsible for absorbing nutrients

Large Intestine

The organ responsible for absorbing water

Rectum

The organ that stores waste material before it exits the body

Pancreas

Gland that makes digestive enzymes and secretes them into the small intestine

Liver

Organ that makes bile to break down fats; also filters poisons and drugs out of the blood

Gall Bladder

Stores bile produced by the liver until it is needed in the small intestine

Heart

Muscular organ that pumps blood throughout the body

Artery

A blood vessel that carries blood away from the heart to the body.

Vein

A blood vessel that carries blood toward the heart from the body

Blood

The fluid that is pumped by the heart, it carries oxygen and nutrients to the tissues and carries waste products away. It also contains cells of the immune system.

Lungs

Main organs of the respiratory system, where gas exchange takes place.

Diaphragm

Large, flat muscle at the bottom of the chest cavity that helps with breathing

Villi

Small fingerlike projections on the walls of the small intestines that increase surface area

Alveoli

thin-walled microscopic air sacs in the lungs where the exchange of oxygen and carbon dioxide takes place

Enzyme

protein that speeds up a chemical reaction

Protein

A food group that is essential for the growth and repair of new cells

Carbohydrate

A food group that provides energy

Fibre

A food group that helps clean the digestive system

Fat

A food group used for insulation and energy storage

Ingestion

The stage of digestion where food enters the body

Egestion

The stage of digestion where food leaves the body

Saliva

A chemical found in the mouth that lubricates food, making it easier to swallow, and helps digest food

Bolus

After food has been chewed up and mixed with saliva it forms this substance.

Peristalsis

The wave like muscular movement that occurs in the oesophagus to move a bolus

Chemical digestion

Enzymes and stomach acid are an example of this type of digestion

Mechanical Digestion

Chewing and muscle churning are an example of this type of digestion.

Right Ventricle

The part of the heart that pumps blood from the heart to the lungs

Left Ventricle

The part of the heart that pumps blood from the heart to the body

Right Atrium

The part of the heart that receives blood returning from the body

Left Atrium

The part of the heart that receives blood returning from the lungs

Aorta

The main artery that takes blood away from the heart to the body

Vena Cava

The main vein that returns blood to the heart from the body

Pulmonary Vein

The vein that carries blood from the lungs to the left ventricle of the heart

Pulmonary Artery

The artery that carries blood from the right ventricle to the lungs

Mouth

The opening through which food is taken in. It is the site where food enters the body.

Anus

Opening of the rectum to the outside of the body

Capillary

A tiny blood vessel where substances are exchanged between the blood and the body cells

Arteriole

A blood vessel that extends between an artery and a capillary bed.

Venuole

Collects blood from the CAPILLARIES and join to the VEINS

Bronchi

The passages that branch from the trachea and direct air into the lungs

Trachea

windpipe; tube through which air moves

Bronchiole

Branch out from the bronchi and carry oxygen to the alveoli

Testes

Organ that produces sperm

Ovaries

Organs that produce eggs

Sperm

The male sex cell. Sperm fertilise an egg, resulting in an embryo.

Egg

The female sex cell. The egg is fertilised by a sperm, resulting in an embryo.

Fertilisation

Where two gametes successful join together to form a zygote

Gamete

A name for sex cells. In animals, sperm are the male gamete and an egg is the female gamete. In plants, pollen is the male gamete and an ovule is the female gamete.

Fallopian tube

A tube that transports the egg from the ovary to the uterus.

Uterus

Organ of the female reproductive system in which a fertilized egg can develop. Also called the womb.

Epididymis

Structure in the male reproductive system in which sperm fully mature and are stored.

Urethra

Tube through which sperm are released from the body.

Asexual reproduction

Reproduction that does not involve fertilisation (no gametes invovled).

Sexual reproduction

Reproduction involving fertilisation (sperm + egg or pollen vs ovule)

Internal Fertilisation

When fertilisation happens inside the bodies of the parents. e.g: occurs in humans

External Fertilisation

When fertilisation happens outside the bodies of the parents. e.g: occurs in fish