Nutrition Heart Diaphragm Artery Vein Capillary BreathingCirculation Energy Lungs DigestionGas exchange Respiration Blood Life processes Enzymes Glucose Oxygen Carbon dioxide Haemoglobin Blood vessels

alveoli – tiny air sacs in the lung across which gas exchange occurs (singular = ‘alveolus’) amino acid – individual components that make up proteins anus – the final opening of the digestive tract through which indigestible material is removed artery – a blood vessel that carries blood away from the heart breathe – draw air into (inhale), and expel out of (exhale), the lungs capillary – minute blood vessels connecting small arteries with small veins carbohydrate – essential component of living cells and a source of energy; includes sugars and starch carbon dioxide – colourless gas formed during respiration, CO 2 diaphragm – thin, dome-shaped muscle helps you breathe and separates the lungs from your stomach and intestines diffusion – the spreading out of particles through random motion from regions of higher concentration to regions of lower concentration enzyme – special proteins that can break large molecules into small molecules fat – a kind of body tissue used to provide energy and to store energy in the body and insulate it against the cold gas exchange – the transfer of gases contained in an organism; in a human, gases contained in the blood exchange with gases contained in the air glucose – a type of carbohydrate, obtained through digestion of the food we eat; human body's key source of energy; important for respiration gullet – the tube between the mouth and the stomach that food passes along haemoglobin – oxygen-transport protein in the red blood cells of most vertebrates; contains iron heart – a muscular organ that pumps blood to your body large intestine – a final part of the digestive system; absorbs water from the remaining indigestible food matter lungs – a pair of organs in the chest that serve to remove carbon dioxide and provide oxygen to the blood minerals – chemical elements required by living organisms to grow, develop and stay healthy, e.g. calcium, magnesium, potassium, sodium, zinc obese – very overweight; a medical condition in which excess body fat has built up to the extent that it may have an adverse effect on health oxygen – colourless gas required for aerobic respiration, O 2 plaque – a mixture of fat, cholesterol and blood cells that stick to the walls of blood vessels; makes the arteries narrower so less blood can flow through protein – large group of compounds that are essential constituents of living cells; consist of polymers of amino acids; essential in the diet of animals for growth and for repair of tissues; can be obtained from meat and eggs and milk rectum – final straight portion of large intestine, ending with the anus respiration – chemical reactions that occur in the cells of living organisms; takes glucose and oxygen to release energy small intestine – part of the digestive tract between the stomach and large intestine; where much of the digestion and absorption of food takes place stomach – a muscular, hollow organ that is part of the digestive system; between the gullet and small intestine; secretes enzymes and acid to aid food digestion valves – allows blood flow in only one direction vein – a blood vessel that carries blood towards the heart villi – microscopic, finger-like projections in the lining of the small intestine that absorb nutrients into the body vitamin – compound required as a vital nutrient in tiny amounts by an organism