Circulatory system:
The circulatory system (or cardiovascular system) is an organ system that moves nutrients, gases, and wastes to and from cells, and helps stabilize body temperature and pH to maintain homeostasis. While humans, as well as other vertebrates have a closed circulatory system, some invertebrate groups have open circulatory system. The most primitive animal phyla lack circulatory systems.
Human circulatory system:
The main components of the human circulatory system are the heart, the blood, and the blood vessels.
Furthermore, these components can either belong to the systemic circulation and the pulmonary circulation. The systemic circulation is the main part of the circulatory system, while the pulmonary system oxygenates the blood.
Systemic circulation:
Systemic circulation is the portion of the cardiovascular system which carries oxygenated blood away from the heart, to the body, and returns deoxygenated blood back to the heart.
Arteries always take blood away from the heart, regardless of their oxygenation, and veins always bring blood back. In general, arteries bring oxygenated blood to the tissues; veins bring deoxygenated blood back to the heart. In the case of the pulmonary vessels, however, the oxygenation is reversed: the pulmonary artery takes deoxygenated blood from the heart to the lungs, and oxygenated blood is pumped back through the pulmonary vein to the heart. As blood circulates through the body, oxygen and nutrients diffuse from the blood into cells surrounding the capillaries, and carbon dioxide diffuses into the blood from the capillary cells.
The release of oxygen from red blood cells or erythrocytes is regulated in mammals. It increases with an increase of carbon dioxide in tissues, an increase in temperature, or a decrease in pH. Such characteristics are exhibited by tissues undergoing high metabolism, as they require increased levels of oxygen.
The main components of the human circulatory system are the heart, the blood, and the blood vessels.
Furthermore, these components can either belong to the systemic circulation and the pulmonary circulation. The systemic circulation is the main part of the circulatory system, while the pulmonary system oxygenates the blood.
Systemic circulation:
Systemic circulation is the portion of the cardiovascular system which carries oxygenated blood away from the heart, to the body, and returns deoxygenated blood back to the heart.
Arteries always take blood away from the heart, regardless of their oxygenation, and veins always bring blood back. In general, arteries bring oxygenated blood to the tissues; veins bring deoxygenated blood back to the heart. In the case of the pulmonary vessels, however, the oxygenation is reversed: the pulmonary artery takes deoxygenated blood from the heart to the lungs, and oxygenated blood is pumped back through the pulmonary vein to the heart. As blood circulates through the body, oxygen and nutrients diffuse from the blood into cells surrounding the capillaries, and carbon dioxide diffuses into the blood from the capillary cells.
The release of oxygen from red blood cells or erythrocytes is regulated in mammals. It increases with an increase of carbon dioxide in tissues, an increase in temperature, or a decrease in pH. Such characteristics are exhibited by tissues undergoing high metabolism, as they require increased levels of oxygen.
Pulmonary circulation:
Main article: Pulmonary circulation
Pulmonary circulation is the portion of the cardiovascular system which carries oxygen-depleted blood away from the heart, to the lungs, and returns oxygenated blood back to the heart.
De-oxygenated blood enters the right atrium of the heart and flows into the right ventricle where it is pumped through the pulmonary arteries to the lungs. Pulmonary veins return the now oxygen-rich blood to the heart, where it enters the left atrium before flowing into the left ventricle. From the left ventricle the oxygen-rich blood is pumped out via the aorta, and on to the rest of the body.
Main article: Pulmonary circulation
Pulmonary circulation is the portion of the cardiovascular system which carries oxygen-depleted blood away from the heart, to the lungs, and returns oxygenated blood back to the heart.
De-oxygenated blood enters the right atrium of the heart and flows into the right ventricle where it is pumped through the pulmonary arteries to the lungs. Pulmonary veins return the now oxygen-rich blood to the heart, where it enters the left atrium before flowing into the left ventricle. From the left ventricle the oxygen-rich blood is pumped out via the aorta, and on to the rest of the body.
Systemic circulation is the portion of the cardiovascular system which carries oxygenated blood away from the heart, to the body, and returns deoxygenated blood back to the heart. The term is contrasted with pulmonary circulation.
Main article: Pulmonary circulation
Pulmonary circulation: is the portion of the cardiovascular system which carries oxygen-depleted blood away from the heart, to the lungs, and returns oxygenated blood back to the heart. The term is contrasted with systemic circulation.
Respiratory system:
Among quadrupeds, the respiratory system generally includes tubes, such as the bronchi, used to carry air to the lungs, where gas exchange takes place. A diaphragm pulls air in and pushes it out. Respiratory systems of various types are found in a wide variety of organisms.
In humans and other mammals, the respiratory system consists of the airways, the lungs, and the respiratory muscles that mediate the movement of air into and out of the body. Within the alveolar system of the lungs, molecules of oxygen and carbon dioxide are passively exchanged, by diffusion, between the gaseous environment and the blood. Thus, the respiratory system facilitates oxygenation of the blood with a concomitant removal of carbon dioxide and other gaseous metabolic wastes from the circulation. The system also helps to maintain the acid-base balance of the body through the efficient removal of carbon dioxide from the blood.
Among quadrupeds, the respiratory system generally includes tubes, such as the bronchi, used to carry air to the lungs, where gas exchange takes place. A diaphragm pulls air in and pushes it out. Respiratory systems of various types are found in a wide variety of organisms.
In humans and other mammals, the respiratory system consists of the airways, the lungs, and the respiratory muscles that mediate the movement of air into and out of the body. Within the alveolar system of the lungs, molecules of oxygen and carbon dioxide are passively exchanged, by diffusion, between the gaseous environment and the blood. Thus, the respiratory system facilitates oxygenation of the blood with a concomitant removal of carbon dioxide and other gaseous metabolic wastes from the circulation. The system also helps to maintain the acid-base balance of the body through the efficient removal of carbon dioxide from the blood.
Anatomy:
In humans and other animals, the respiratory system can be conveniently subdivided into an upper respiratory tract (or conducting zone) and lower respiratory tract (respiratory zone), trachea and lungs.
Air moves through the body in the following order:
In humans and other animals, the respiratory system can be conveniently subdivided into an upper respiratory tract (or conducting zone) and lower respiratory tract (respiratory zone), trachea and lungs.
Air moves through the body in the following order:
