Understanding Homeostasis

  • Homeostasis is the process by which the body maintains a constant internal environment, despite changes in the external environment. This involves a series of physiological processes and feedback mechanisms.
  • The main variables that need to be kept constant include body temperature, blood glucose levels, water potential of the blood, and carbon dioxide concentration.

Temperature Regulation

  • During exercise, body temperature increases due to metabolic reactions. This could potentially disrupt enzyme function and cell metabolism.
  • The hypothalamus in the brain controls temperature regulation. When body temperature rises, it triggers vasodilation, where blood vessels widen to increase blood flow and Heat loss.
  • Sweating also increases, providing a cooling effect as the sweat evaporates. This heat loss helps to compensate for the rise in internal temperature due to exercise.

Blood Glucose Regulation

  • Glucose provides the energy for muscle contraction during exercise. As a result, blood glucose levels drop significantly.
  • In response, the pancreas releases the hormone glucagon. This triggers the breakdown of glycogen stored in the muscles and liver into glucose, using the process of glycogenolysis.
  • Furthermore, adrenaline is released during exercise, which also stimulates glycogenolysis, helping to maintain blood glucose levels.

Water and Ion Balance

  • During vigorous exercise, sweating increases to facilitate heat loss. This may result in dehydration if not balanced by fluid intake.
  • The kidney plays a crucial role in maintaining water balance through the process of osmoregulation. The hypothalamus also senses changes in blood water potential and stimulates release of ADH from the pituitary gland, thus influencing urine volume.
  • Intake of isotonic drinks during exercise helps to replace lost water and electrolytes.

Carbon Dioxide Regulation

  • As exercise intensifies, carbon dioxide production from tissues increases due to increased cellular respiration.
  • Carbon dioxide is transported in the blood to the lungs and expelled through exhalation. The concentration of CO2 in the blood is thus regulated by modification of the breathing rate and depth.
  • The brain’s medulla oblongata monitors CO2 levels in the blood and changes the rate and depth of breathing accordingly.

Investigating Homeostasis

  • Exercise provides a good experimental model to understand homeostasis, given it initiates clear alterations to internal conditions.
  • Thermometers and heart rate monitors can be used to study the effects of exercise on body temperature and the circulatory system.
  • Blood glucose levels can be checked using a glucose meter before, during, and after exercise to see how the body responds to maintain glucose homeostasis.
  • Urine samples can be analyzed before and after exercise to determine if dehydration occurred, thus studying water and ion homeostasis regulation.