prevents damaging bone-to-bone contact within movable joints.

Explanation:

Cartilage: A type of connective tissue, cartilage cushions bones inside your joints, along your spine and in your ribcage. Firm, rubbery cartilage protects bones from rubbing against each other.

the oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. this blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. from the left ventricle, the blood passes through the aortic valve to the aorta.

deoxygenated blood leaves through the right ventricle through the pulmonary artery. from the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve), into the right ventricle.