Friday, 15 March 2013

Human Respiratory System Functions

Human Respiratory System Functions
The functions of the human respiratory system are carried out by a group of organs that constitute the system. This article will provide you with a brief overview of these functions.
It is a common fact that there are different bodily systems assigned with different functions. This includes the digestive system, nervous system, reproductive system, circulatory system, endocrine system, immune system, integumentary system, muscular system, respiratory system, skeletal system, urinary system and the lymphatic system. These systems comprise various organs, whose joint efforts help in successfully performing their individual function.

Human Respiratory System

In simple words, the respiratory system can be explained as a group of organs that help us to breathe. Breathing involves inhalation of oxygen and exhalation of carbon dioxide. Even though, the process of breathing appears to be very simple, it involves the proper functioning of various organs. The respiratory system parts include the nose, nasal cavity, pharynx, larynx, trachea, bronchi, alveoli and lungs. The respiratory system organs are classified into two sections - the upper respiratory tract that includes the nose, nasal cavity, pharynx and larynx and the lower respiratory tract that contains the trachea, bronchi, alveoli and lungs. These organs enable us to breathe.

Functions of The Respiratory System

Oxygen is required by the body cells for their normal functioning and this requirement is fulfilled by the human respiratory system. During this process, it helps in expelling the carbon dioxide that is discarded by the cells as metabolic waste. So, the most important and primary function of the system is to supply oxygen to the body cells. A basic idea about the respiratory system will be beneficial in understanding these functions.

During inhalation, air is drawn from the atmosphere, through the nose (sometimes, through mouth too). This is caused by the contraction of the diaphragm (the sheet of muscles that separate the thoracic cavity from the abdominal cavity) and the intercostal muscles attached to the ribs. As they contract, the volume of the thoracic cavity increases, thereby decreasing the air pressure. This results in inhalation, that is the process of drawing in air from the atmosphere, so that the thoracic cavity gets filled.

The air taken through the nose is filtered, moistened or heated in the nasal cavity, before it passes to the pharynx. The pharynx is a pathway that is common for both air and food and is continuous with the esophagus. Pharynx function is to facilitate passage of air to the trachea. However, the pharynx opens up to the wind pipe or trachea, in order to facilitate breathing. The flap-like structure (called epiglottis) located just above the opening, closes this orifice, when food is swallowed. This structure ensures that food particles do not enter the trachea. It is near this opening that the voice box or the larynx is situated. This structure performs the function of protecting the trachea and also for production of sound.

The air enters the trachea or windpipe, which is a tube-like structure with tough covering. Trachea functions include facilitating air passage and moistening of the air. The trachea branches into two tube-like structures called bronchi. Each bronchus travels into the left and right lungs respectively. Lungs is the spongy structures that house the bronchi, which divide into numerous tubes called bronchioles. Each bronchiole ends with numerous circular sacs called alveoli. The alveoli are the basic functional units that facilitates gaseous exchange, which is the most important among the human respiratory system functions. The carbon dioxide expelled by the cells are carried by the venous blood to the alveoli. The alveoli contain numerous thin-walled capillaries through which blood passes. Inside the alveoli, the carbon dioxide is released and oxygen is drawn inside the capillaries. The oxygenated blood is carried to the heart, which pumps it to the different parts of the body. So, during inhalation, oxygen is absorbed and carbon dioxide is expelled during exhalation that is caused by relaxation of the diaphragm and the intercostal muscles.
Read more at Buzzle: http://www.buzzle.com/articles/human-respiratory-system-functions.html

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