Physiology

• exhaled by the lungs and water that is absorbed from the

  tissues.
• The intracellular fluid contains smaller amounts of these substances.
• The extracellular fluid is in constant motion throughout the body, transported rapidly in the circulating blood and then mixed between the blood and the tissue fluids by diffusion through the capillary walls.
• In the extracellular fluid are the ions and nutrients needed by the cells to maintain cell life.
• All cells live in essentially the same environment—the extracellular fluid.
• The extracellular fluid is also called the internal environment of the body, or the milieu intérieur, a term introduced more than 100 years ago by the great 19th-century French physiologist Claude Bernard.
• Cells are capable of living, growing, and performing their special functions as long as the proper concentrations of oxygen, glucose, different ions, amino acids, fatty substances, and other constituents are available in this internal environment.
• The extracellular fluid contains large amounts of sodium, chloride, and bicarbonate ions plus nutrients for the cells, such as oxygen, glucose, fatty acids, and amino acids.
• The extracellular fluid also contains carbon dioxide that is exhaled by the lungs and water that is absorbed from the tissues.
• amino acids, and fatty substances.
• Intracellular fluid contains small amounts of these

  ions and nutrients.
• Extracellular fluid is in constant motion throughout the body, transported rapidly in the circulating blood and then mixed between the blood and the tissue fluids by diffusion through the capillary walls.
• In the extracellular fluid are the ions and nutrients needed by the cells to maintain cell life.
• All cells live in essentially the same environment—the extracellular fluid.
• The extracellular fluid is also called the internal environment of the body, or the milieu intérieur, a term introduced more than 100 years ago by the great 19th-century French physiologist Claude Bernard.
• Cells are capable of living, growing, and performing their special functions as long as the proper concentrations of oxygen, glucose, different ions, amino acids, fatty substances, and other constituents are available in this internal environment.
• Transport of extracellular fluid from the cells to the lungs for excretion, and other cellular waste products to the kidneys for excretion, occur through different transport mechanisms.
• The intracellular fluid differs significantly from the extracellular fluid; for example, it contains large amounts of potassium, magnesium, and phosphate ions instead of the sodium and chloride ions found in the extracellular fluid.
• Transport of extracellular fluid from the cells to the lungs for excretion, and other cellular waste products to the kidneys for excretion, occur through different transport mechanisms.
• Special mechanisms for transporting ions through the cell membranes maintain the ion concentration differences between the extracellular and intracellular fluids.
• Homeostasis, as defined by physiologists, is the maintenance of nearly constant conditions in the internal environment.
• The intracellular fluid differs significantly from the extracellular fluid; for example, it contains large amounts of potassium, magnesium, and phosphate ions instead of the sodium and chloride ions found in the extracellular fluid.
• All organs and tissues of the body perform functions that help maintain these relatively constant conditions.
• Special mechanisms for transporting ions through the cell membranes maintain the ion concentration differences between the extracellular and intracellular fluids.
• The lungs provide oxygen to the extracellular fluid to replenish the oxygen used by the cells, the kidneys maintain constant ion concentrations, and the gastrointestinal system provides nutrients.
• Homeostasis, as defined by physiologists, is the maintenance of nearly constant conditions in the internal environment.
• Homeostasis is maintained by the different functional systems of the body working together.
• All organs and tissues of the body perform functions that help maintain these relatively constant conditions.
• Extracellular fluid is transported through all parts of the body in two stages: movement of blood through the body in the blood vessels and movement of fluid between the blood capillaries and the intercellular spaces between the tissue cells.
• The lungs provide oxygen to the extracellular fluid to replenish the oxygen used by the cells, the kidneys maintain constant ion concentrations, and the gastrointestinal system provides nutrients.
• Homeostasis is maintained by the different functional systems of the body working together.
• All the blood in the circulation traverses the entire circulatory circuit an average of once each minute when the body is at rest and as many as six times each minute when a person is extremely active.
• Extracellular fluid is transported through all parts of the body in two stages: movement of blood through the body in the blood vessels and movement of fluid between the blood capillaries and the intercellular spaces between the tissue cells.
• As blood passes through the blood capillaries, continual exchange of extracellular fluid also occurs between the plasma portion of the blood and the interstitial fluid that fills the intercellular spaces.
• All the blood in the circulation traverses the entire circulatory circuit an average of once each minute when the body is at rest and as many as six times each minute when a person is extremely active.
• The walls of the capillaries are permeable to most molecules in the plasma of the blood, with the exception of plasma protein molecules, which are too large to readily pass through the capillaries.
• As blood passes through the blood capillaries, continual exchange of extracellular fluid also occurs between the plasma portion of the blood and the interstitial fluid that fills the intercellular spaces.
• Large amounts of fluid and its dissolved constituents diffuse back and forth between the blood and the tissue spaces, as shown by the arrows.
• This process of diffusion is caused by kinetic motion of the molecules in both the plasma and the interstitial fluid.
• The walls of the capillaries are permeable to most molecules in the plasma of the blood, with the exception of plasma protein molecules, which are too large to readily pass through the capillaries.