respiratory system

• take in oxygen for respiration in cells • excrete co2 and water vapour which are waste of respiration • allow gaseous exchange to occur between blood and lungs

filters, warms and moistens the air before it reaches the lungs

takes air down to the lungs

takes air into lungs

takes air to alveoli

air sacs surrounded by capillaries where gas exchange occurs

protects lungs from infection

protect lungs

expand and contract the chest

sheet of muscle beneath the lungs that controls the volume of the chest by contractions

oxygen from alveoli diffuses through walls of alveoli and capilarries, into the blood co2 from blood through walls of capillaries and alveoli into alveoli

• intercostal muscles contract , causing the ribs to move out and up • diaphragm contracts, causing it to move down • volume of the chest increases • pressure on lungs decreases • air is sucked in

-intercostal muscles relax, causing the ribs to move in and down -diaphragm relaxes, causing it to move up -volume of chest decreases -pressure on the lungs increases air is forced out

• nose • trachea, bronchi, bronchiole is a system of tubes that carry air in and out of the lungs • intercostal muscles and diaphragm relax and contract at the same time to draw air in and push air out of the lungs

• heart pumps deoxygenated blood through pulmonary artery to the lungs to get rid of co2 and take 02 • capillaries that surround the alveoli join together to form pulmonary vein • all cells of all systems receive o2 that’s been taken into the blood by the respiratory system • when eating, the epiglottis covers the trachea to prevent food going down the wrong way

larynx -voice box

epiglottis

• 2 tubes with two ‘straws’’ , w limewater in both • breathe in through one, out in the other • the one you breathe out in the limewater will turn milky