The Physiology of Fitness physiology | Page 2

Thoracic cavity- The thoracic cavity protects and holds the lungs , heart , trachea , esophagus , endocrine glands , thoracic aorta and the pulmonary artery . Enclosed by the ribs , breast bone and vertebral column it is the second-largest hollow space of the human body .
Lungs- The lungs main function is to help oxygen from the air we breathe enter the red cells in the blood . Red blood cells then carry oxygen around the body to be used in the cells found in our body . The lungs also help the body to get rid of CO2 gas when we breathe out .
Tidal volume is the volume of air you breathe in a single breath . Exercise causes an increase in tidal volume because your requirements for oxygen go up as your working muscles need the oxygen , so the increase in tidal volume is necessary to meet your bodies increase in oxygen requirements . Your breathing rate will also rise as your body needs to get more oxygen to the muscles and to get rid of the carbon dioxide , when an athlete works their breathing rate will rise but slower because they have a higher tidal volume which means they can breathe more oxygen in in one breath . During a game the player ’ s fatigue so they will be trying to take in as much oxygen as they can from each breath so they can carry on performing .
If the breathing rate and tidal volume do not increase during acute exercise they will fatigue very quickly and will not be able to perform , their working muscle will be deprived of oxygen so they will be working anaerobically , this means a lot of waste product such as lactic acid will form and cause the player to stop and recover . So it is essential for both tidal volume and breathing rate to increase .
Cardiovascular system :
The cardiovascular system consists of the heart , blood vessels , and blood . The four major functions of the cardiovascular system are : To transport nutrients , gases and waste products around the body , to protect the body from infection and blood loss , to help the body maintain a constant body temperature and to help maintain fluid balance within the body .
Transportation : the cardiovascular system goes all around the body like a network , this network allows blood to deliver and expel nutrients , gases , waste products and messages throughout the body . Nutrients such as glucose from digested carbohydrate are delivered from the digestive tract to the muscles and organs that require them for energy this is one