Ninja Nerd - Circulatory System | Pulmonary Circulation

Pulmonary Circulation

• The purpose of the pulmonary circulation is to pump blood from the right side of the heart to the lungs, where oxygen is picked up and CO2 is dropped off.
• The oxygen-rich blood is then delivered to the left side of the heart.

Pulmonary Circulation Pathway

• Right ventricle: the starting point of the pulmonary circulation, where the heart pumps blood through the pulmonary semilunar valve.
• Pulmonary semilunar valve: the valve that allows blood to flow from the right ventricle into the pulmonary trunk.
• Pulmonary trunk: a large artery that receives blood from the right ventricle and splits into the right and left pulmonary arteries.
• Right and left pulmonary arteries: arteries that carry deoxygenated blood from the pulmonary trunk to the lungs.
• Pulmonary arterioles: small arteries that branch off from the pulmonary arteries and have high resistance, controlling constriction and dilation responses.
• Pulmonary capillaries: tiny vessels where gas exchange occurs, and oxygen is picked up and CO2 is dropped off.
• Pulmonary venules: small veins that receive oxygen-rich blood from the pulmonary capillaries.
• Pulmonary veins: veins that collect oxygen-rich blood from the pulmonary venules and return it to the left atrium.
• Left atrium: the chamber of the heart that receives oxygen-rich blood from the pulmonary veins.
• Mitral valve (or bicuspid valve): the valve that allows blood to flow from the left atrium into the left ventricle.
• Left ventricle: the final chamber of the heart, where the oxygen-rich blood is pumped out to the rest of the body.

Important Notes

• Arteries carry blood away from the heart, while veins carry blood back to the heart.
• The pulmonary arteries are deoxygenated, while the pulmonary veins are oxygenated.
• Gas exchange occurs in the alveoli, small structural units within the lungs.

Pulmonary Circulation

• Pulmonary circulation pumps blood from the right side of the heart to the lungs for oxygenation and CO2 removal.

Pulmonary Circulation Pathway

• Right ventricle pumps blood through the pulmonary semilunar valve into the pulmonary trunk.
• Pulmonary trunk splits into right and left pulmonary arteries, carrying deoxygenated blood to the lungs.
• Pulmonary arteries branch into pulmonary arterioles, which control constriction and dilation responses.
• Pulmonary arterioles lead to pulmonary capillaries, where gas exchange occurs (oxygen pickup and CO2 removal).
• Oxygen-rich blood from pulmonary capillaries flows into pulmonary venules, then into pulmonary veins.
• Pulmonary veins return oxygen-rich blood to the left atrium, which then flows through the mitral valve into the left ventricle.
• Left ventricle pumps oxygen-rich blood out to the rest of the body.

Key Concepts

• Arteries transport blood away from the heart, while veins transport blood back to the heart.
• Pulmonary arteries are deoxygenated, while pulmonary veins are oxygenated.
• Gas exchange occurs in the alveoli, small structural units within the lungs.