Respiratory System and Circulatory System

Respiratory System

Respiration is the process of releasing energy from the food we take. The respiratory system consists of the nostrils, larynx, pharynx, bronchi, tracheae and lungs. Respiration is the breakdown of absorbed food with the help of oxygen. During this process, carbon dioxide, water and a lot of energy are produced. This energy is made available to the cells of the body.

The necessary steps to be taken to keep our lungs healthy are:

1. Avoid smoking.
2. Take fresh food.
3. Avoid taking drugs.
4. Control air pollution.

Circulatory system

The circulatory system is responsible for transportation of nutrients obtained from the food we ingest. It is also responsible for carrying life supportive oxygen to all our cells for the oxidation of food and release of energy required for smooth functioning of our body. Circulatory System consists of the following parts:

1. Blood
2. Heart
3. Blood Vessels

Blood

Blood is a fluid connective tissue which is red in colour, alkaline in nature and salty in taste. A human adult under normal condition has 4.7 to 5 liters of blood. Blood consists of 45 % of blood cells and 55% of plasma. Blood circulates continuously in every part of the body. Blood comprises Plasma, Red Blood Cells (RBC), White Blood Cells(WBC), and platelets. Blood cells can flow easily through blood vessels because they are a minute.

Heart

The human heart is a cone shaped muscular organ formed by cardiac muscular organ formed by cardiac muscles. Its size is similar to that of a closed fist and weighs about 350 grams. The heart is surrounded by a tough membrane called Pericardium. Our heart has four chambers: two auricles and two ventricles. The right auricle and the right ventricle are connected by tricuspid valves. The left auricle and left ventricle are connected by Bicuspid or Mitral valve.

Blood Vessels

Our body has three types of blood vessels. They are:

1. Arteries
2. Veins
3. Capillaries

Function of Artery, Capillaries and Vein

1. Artery: Arteries carries the oxygenated blood to the different parts of the body, organs and tissues. Except the pulmonary artery, all the other arteries carry oxygenated and pure blood.
2. Capillaries: Arteries further branch out to form small arterioles. These arterioles further branch to form a fine network of blood vessels known as capillaries. Its function is to interconnect the arteriole and venule.
3. Vein: It's function is to transport blood from different parts and organs of the body to the heart. All veins except the pulmonary vein contain deoxygenated blood.

Blood Circulation in our body

The heart is the only organ that pumps blood all over our body. The oxygenated blood pumped out from the left ventricle is carried by aorta which branches into smaller arteries that carry blood to different organs and tissues. These small arteries are further divided into arterioles and capillaries. The capillaries supply blood to all the tissues and organs. The oxygen content of the blood is used up by the cells for respiration. The de-oxygenated blood makes way towards the heart via venules which then unite to form veins. They carry blood back to the right auricle through superior and inferior venacava. Superior Venacava brings impure blood to right auricle from the brain, heart or the upper part of the body and the inferior part of the body brings impure blood to the right auricle from the lower part of the body. As soon as the right auricle is filled with impure blood, the tricuspid valve in between opens. So, the blood moves into the right ventricle. The tricuspid valve closes once the right ventricle is filled with blood. The blood is then pumped towards the pulmonary artery. The pulmonary artery is divided into left and right branches that are joined to the lungs. Through these, blood reaches the alveoli and carbon dioxide passes into the alveoli from the capillaries. This way the process of carrying out carbon dioxide and taking in oxygen into the blood takes place continuously.