Physiology Essay Example | Topics and Well Written Essays - 500 words - 2

Physiology - Essay Example In high temperatures, the body can be cooled off through sweating and wearing of a jacket and when temperatures are low, they can be heated by wearing a jacket and through shivering. The pulse is the periodic dilation of the artery that is produced by the rhythmic opening and closing of the aortic valve in the heart. It can be felt through the application of pressure by firm fingertips to the skin where the arteries travel near the surface of the skin. The common pulse points are the radial artery in the wrist, the brachial artery inside the elbow and the carotid artery of the neck (Yagiela, 1995). Pulse rates differ from one person to another and it decreases with age. Alterations between normal and weak pulses indicate heart failure while rapid pulses indicate serious cardiac diseases, vigorous exercises or a relatively mild fever. Head injuries may result in slow pulse rates though this is exceptional in highly trained athletes who were slow pulse rate is considered normal. The maximal heart rate is that of 200 beat/min which is in young people. The maximal heart rate is determined genetically and cannot be modified by exercise or by external factors. According to Yagiela (1995) respiration is the process through which the body acquires oxygen and in turn removes carbon dioxide through the nasal cavity into the lungs (Lombardi, Lown and Verrier, 2005). This simple exchange of gases occurs through a process known as diffusion which requires a concentration gradient. Oxygen concentration has to be kept at higher levels in the alveoli than in the blood and the carbon dioxide concentration in the blood has to be kept at higher levels than in the alveoli. This is done through the active process of breathing that calls for contraction of the skeletal muscles including the diaphragm and the external intercostals muscles. The intercostals muscles are located in between the ribs while the diaphragm is muscle sheet between the