The Cardiovascular System consists of two components which are the heart and the blood vessels. The heart performs the function of pumping blood while the blood vessels act as the channels through which blood is transported to various parts of the body. The process of blood circulation to different parts of the body is divided into two functional structures which are the pulmonary circuit and the systemic circuit. The pulmonary circuit refers to the flow of blood through the lungs while the systemic circuit refers to the movement of blood to other parts of the body. The cardiovascular system has the heart as its primary organ, and it performs vital functions that facilitate circulation of oxygenated blood throughout the body. The contractions of the heart create pressure on the blood vessels which pushes blood to all parts of the body.
The heart also pumps blood through the lungs where it receives oxygen and gets rid of carbon dioxide. This oxygenated blood is usually transported through the arteries while the blood rich in carbon dioxide is transported through the veins. Notably, the blood is responsible for transportation of components such as oxygen, nutrients, waste and even enzymes. The exchange of nutrients and oxygen contained in the blood occurs across the walls of capillaries thus refreshing the blood and tissue fluid.The respiratory system in humans refers to a combination of several organs which are responsible for oxygen intake into the body and expulsion of carbon dioxide.
The lungs are the central organ in the respiratory system as most of the respiratory processes take place in them. When we breathe, air rich in oxygen is taken in through the nostrils, the sinuses into the lungs. The sinuses are hollow spaces in the skull which allow air to go through and help in regulating the temperature of the air breathed in. The trachea which is also called the windpipe carries air down into the lungs, and it branches to into the bronchi which are the two tubes that attach to the to each lung. The trachea is responsible for filtering the air leaving it free of any impurities. The bronchial tubes contain tiny hairs which carry mucus, a sticky substance that traps any impurities that may have invaded the lungs.
Mucus, a viscous fluid, collects dust, germs and other matter that has invaded the lungs. We expel mucus when we sneeze, cough, spit or swallow.The right lung is larger than the left lung as it has three lobes while the left has two. The left lung is smaller so as to give enough space for the heart which also plays a significant role in the respiratory processes. The lung lobes contain small spongy sacs called alveoli, which are the structures that facilitate the exchange of oxygen and carbon dioxide.
The alveoli have very thin walls made up of a single layer tissue called the epithelial cells and tiny blood vessels known as the pulmonary capillaries. Air is exchanged through the capillaries where oxygen is absorbed, and carbon dioxide is expelled and breathed out. The blood rich in oxygen goes back to the heart where it is pumped to the rest of the body. The circulatory and the respiratory system work coherently to ensure proper circulation of oxygen throughout the body and also in the expulsion of carbon dioxide out of the body. Oxygen is a critical component that facilitates cellular functions like oxidation. The blood circulation is done by the heart whereby it pumps blood to the lungs as well as to the other parts of the body.