The human body can be compared to a machine, operating continuously as a complicated, yet highly intelligent complex. It is truly amazing when one contemplates bodily processes and its importance in maintaining humans living existence. (Evans, 2004). Therefore the following essay will go on to examine these further.
The respiratory system is an important system, which plays a role in the exchange of gases in and out of the body and essentially helps to provide cells with energy for growth, defence and replication. There are two parts of the respiratory system: the upper and the lower respiratory systems. This essay will fundamentally concentrate on the latter (Schikowski, Sugiri, Ranft, Gehring, Heinrich, Wichmann, Krämer, 2007).
Firstly, oxygen is inhaled into the mouth and passed down into the pharynx (part of the upper respiratory system). It then passes into a slender opening - the glottis - in order to enter into a hollow structure known as the larynx. The larynx, commonly referred to as the voice box, is a structure of incomplete cartilaginous wall, strengthened by ligaments and skeletal muscle. The functions of the larynx are to produce sound from the air breathed in and enable this air to be passed down into the trachea (www.t-enterprise.co.uk).
The goblet cells secrete mucus, a clear fluid-like substance that traps dirt and dust, which may be breathed in through the mouth. The purpose of the cilia is to sweep the mucus upwards towards the pharynx where it is either swallowed or spat out. They work together to prevent harmful particles from entering into the lungs (www.t-enterprise.co.uk).
In combination with the respiratory system, the cardiovascular system allows the exchange of gases, nutrients and hormones between the blood and tissues contained within the body. As this essay will go on to examine, the functions of the cardiovascular system ultimately rely on the heart (www.t-enterprise.co.uk).
Once the oxygen is diffused into the surrounding blood from the alveoli, it bonds with the haemoglobin present in red blood cells. Haemoglobin, the red pigment in red blood cells is responsible for transporting oxygen around the body. The transportation of blood around the body is solely due to the contractions made by the heart. This essay will now go on to investigate this (www.t-enterprise.co.uk).
The circulatory system plays an important role in many of the body's processes including respiration, nutrition, and the removal of wastes and poisons. In respiration it delivers oxygen to the body's cells and removes carbon dioxide from them. In nutrition, it carries digested food substances to the cells. Nutrients from food enter the bloodstream by passing through the walls of the small intestine into the capillaries. The blood then carries most of the nutrients to the liver, where some of these are extracted and stored for release back into the blood as and when the body needs them. Other nutrients are converted by the liver into substances which are required in the production of energy, ...