nutrition• The digestive system,the respiratory system,the circulatory system and the excretory system carry out the function of nutrition.
The digestive system• The digestive system is made up of the digestive glands and the digestive tract. • The digestive glands: salivary glands, liver and pancreas. • The digestive tract: the mouth, the pharynx, the oesophagus, the stomach, the small intestine and the large intestine.
The respiratory system• The respiratory sytem is in charge of breathing. • First we inhale air and it goes into to the lungs. • Then we exhale air sending it out of the lungs.• It is made up of: the nostrils, the pharynx, the larynx, the trachea, the bronchi and the lungs.• The muscle that creates the movements involved in breathing is the diaphragm.
The excretory system• The excretory system is made up of: • Sweat glands. • The urinary system.
The urinary system• The urinary system is made up of: the kidneys, the ureters, the bladder and the urethra.
The circulatory system• The circulatory system is made up of: the heart, the blood and the blood vessels.• The blood vessels can be: arteries, veins and capillaries.
The blood• Blood is a red liquid tissue made up of cells that float in a red liquid called plasma.• There are three types of blood cells: • Red blood cells • White blood cells • Platelets
The heart• The heart is a muscular organ that pumps blood around the body.• Blood enters the atria through the veins and passes through the ventricles. Between the atria and ventricles there are valves.
Human circulation• Human circulation is closed. In mammals, the heart septum separates the two halves of the heart. This prevents blood with oxygen from mixing with the blood carrying carbon dioxide.• Human circulation is double. The blood follows two routes. • Pulmonary circulation. • Systemic circulation.