RESPIRATION AND THE ORGANS OF RESPIRATORY SYSTEM:

 

 Introduction:

 

An important sign of life is breathing. All living things have always been breathing. That is, oxygen enters their body and carbon dioxide is released by this process, oxidation of food takes place, by which chemical energy is converted into kinetic energy. This kinetic energy is used by the cells in performing their activities. This process is necessary for living organisms. If Breathing stops life ends. Oxygen is needed by all living things depending on the size some animals need less and some more oxygen. One cell and lower animals obtain oxygen from their environment. In animals that have an organized circulatory system, oxygen reaches all the cells through the blood itself. The air from the outside goes into the lungs.  Blood vessels that bring blood to the lungs. By dividing, the veins lay a network of capillaries. There is no part of the lungs where there is no capillary network. Oxygen from the air in the lungs penetrates into the red blood cells through the thick walls of the capillary vessels.

Organs of the respiratory system:

 

The respiratory system  is very important for life. Life requires energy and this energy is obtained from the breakdown of digested food. Breaking down process is not possible without oxygen. Respiration is the process by which oxygen is absorbed into the body and carbon dioxide is released. Oxygen is a colourless gas that is present in the air. When we breathe, we take the oxygen gas from the air and carry it to the blood, and from the blood, this gas reaches all the cells of the body. Cells produce carbon dioxide, a waste product of the body, before this gas accumulates in the body to harmful levels and removes it from the blood.

The process of respiration consists of two parts.

 

(1) External respiration.

 

(2) Internal respiration.

 

(1) External respiration:

Oxygen and carbon dioxide are exchanged between body cells and the outside atmosphere

 

 internal disintegration:

 

It involves the transport of oxygen through the blood to the cells and the use of oxygen in the cells. The respiratory system carries oxygen throughout the body. This is consisted of two lungs that are in the chest. They have air pipes which connect them to mouth and nose ,they look like the branches of a bush.

The lungs have a large blood supply and half of the blood from the heart goes to the lungs to get oxygen.

 

 

Nose and mouth:

We can breathe through nose or mouth equally but we mostly breathe only through nose. The need to breathe through the mouth occurs only when we need excess air like during running or exercising.

 

Generally, the air passes through the two nostrils and enters a large space that feeds the nasal cavity.

The walls of the nasal cavity called Turbinate have a single mucous membrane  in which the supply of mucus is relatively high. In the process of breathing, the nasal cavity clears the air and large outer  particles stick to the mucous membrane of the nose. Apart from this, the function of heating the cold air before entering the lungs is also done through the nasal cavity.

 

A piece of tissue in the air called the sinus it  is responsible for sensing odours in the air.

 

Some air sacs called SINUS open into the nasal cavity, which sometimes block due to swelling this condition is called sinusitis.

Air passes through the throat or  through the nasal cavity before entering the lungs. At the end of the palate is a small piece of flesh called the uvula. This can be a cause to block air passages of nose and mouth.

 

 LUNGS:

The lungs are , sponge-like organs located in the upper part of the breast and are located in the chest cavity. There is a slight difference in size and shape between the two lungs. The right lung is relatively large and divided into three parts while the left lung  is slightly smaller in size and divided into two parts. 

The combined weight of both lungs of an adult man is about one kilogram. A thin membrane surrounds the inner wall of the lungs and chest. This process, which is called pleiva, protects the lungs during respiration.

 

The lungs are among the last organs to develop during pregnancy, which is why premature born babies commonly suffer from respiratory diseases. The branching ducts of the airway system are the source of air entering and leaving the lungs.

 

The largest airway that runs from the throat to the upper part of the chest, is called trachea, its diameter is about 5 cm and length is 10 cm. The trachea is strong and flexible, so it remains open during the movement of the head and neck while eating to strengthen it. For its entire length, cartilage consists of many horseshoe-like sections made of a strong rubber-like substance.

 

The respiratory tract is tightly connected to the alimentary canal through which food reaches the stomach. In the upper abdomen, the respiratory tract divides into two air ducts, the right and the left. These two ducts go into the lungs and are strong like the respiratory tract. These two ducts pass repeatedly in lungs making branches and the air is divided into the smallest ducts (Bronchioles).

 

The smallest air ducts are about one millimetre in diameter. All bronchi, trees have a moist salivary membrane inside the trachea, trachea, and finer air ducts. On the lining of the large airways are goblet cells that produce mucus to keep the surface moist and goblet cells produce cilia to keep the system clean.

 

 BELLY VIEL:

The cavity of the breast is made of the shell of the ribs. Ribs not only protect the heart and the lungs from damage, but also

play a very important role in the respiratory process

 

 

The diaphragm is a strong sheet of oblique muscle layers that forms the floor of the chest cavity, separating the thoracic organs, the heart, and the lungs from the abdominal organs. Two major blood vessels, the aorta (Aeortoid) and the great vein pass through the stomach along with the oesophagus. As the diaphragm shortens or contracts behind the abdomen during respiration, it flattens and moves downward into the chest.

 

How do we breathe?

Breathing in a normal  condition is due to the movement of the diaphragm. Due to the contraction of the peritoneum, the volume of the chest cavity increases and air quickly enters the lungs and is trapped in this enlarged space. The respiratory system is like a water pump, it depends on the pressure of the air around us as the chest cavity expands and air enters the lungs. When the diaphragm is relaxed, it returns to its original dome-like shape. Breathing in and the remaining air out again is the normal way of breathing. As the diaphragm contracts or expands, the stomach may be seen moving slowly.

 

Muscles need more oxygen due to tiredness  and we take deep breaths but the diaphragm alone cannot provide such deep breaths. In this way, air quickly enters the lungs and when they contract, the air is forced back out. At the ends of the smallest air ducts are alveoli, tiny air sacs that take in oxygen and release carbon dioxide. An adult human's lungs have about three hundred million alveoli. The walls of the alveoli are very thin and they have a network of fine blood vessels like blood capillaries  and they deliver blood to all parts of the body.

 

Air that is rich in oxygen enters the alveoli and the oxygen passes through the capillaries into the red blood cells. The red blood cells contain a red substance called haemoglobin. Haemoglobin forms these red cells, which now contain oxygen, circulate in the blood and carry oxygen to all the cells of the body. and the carbon dioxide produced by all the cells of the body enters the blood and enters the alveoli. Gas exchange takes place in the walls of the alveoli and when we exhale, the carbon dioxide leaves through the capillaries. The amount of air used during respiration varies from time to time. Under normal conditions, an adult man breathes 10 to 14 times per minute and fills the lungs with air for 5 to 10 minutes. Also 500 ml of air is used during strenuous activities like exercise etc.  It reaches 100 litters per minute to provide extra oxygen to all the muscles.