Gases, nutrients, and waste materials travel between capillaries and cells through the IF. Plasma travels through the body in blood vessels and transports a range of materials, including blood cells, proteins (including clotting factors and antibodies), electrolytes, nutrients, gases, and wastes. Approximately 20 percent of the ECF is found in plasma. The ECF accounts for the other one-third of the body’s water content. The second largest volume is the interstitial fluid, which surrounds cells that are not blood cells. In contrast, teeth have the lowest proportion of water, at 8–10 percent.įigure 26.4 A Pie Graph Showing the Proportion of Total Body Fluid in Each of the Body’s Fluid Compartments Most of the water in the body is intracellular fluid. Your brain and kidneys have the highest proportions of water, which composes 80–85 percent of their masses. The percent of body water changes with development, because the proportions of the body given over to each organ and to muscles, fat, bone, and other tissues change from infancy to adulthood ( Figure 26.2). Human beings are mostly water, ranging from about 75 percent of body mass in infants to about 50–60 percent in adults, to as low as 45 percent in old age. An appropriate balance of solutes inside and outside of cells must be maintained to ensure normal function. As a result, water will move into and out of cells and tissues, depending on the relative concentrations of the water and solutes found there. Osmosis is basically the diffusion of water from regions of higher concentration of water to regions of lower concentration of water, along an osmotic gradient across a semi-permeable membrane. In the body, water moves through semi-permeable membranes of cells and from one compartment of the body to another by a process called osmosis. For instance, sodium ions (Na +) and chloride ions (Cl -) are often referred to as electrolytes.

Often in medicine, a mineral dissociated from a salt that carries an electrical charge (an ion) is called an electrolyte. In the human body, solutes vary in different parts of the body, but may include proteins-including those that transport lipids, carbohydrates, and, very importantly, electrolytes. The dissolved substances in a solution are called solutes.

The chemical reactions of life take place in aqueous solutions. Identify the causes and symptoms of edema.Explain the importance of protein channels in the movement of solutes.Contrast the composition of the intracellular fluid with that of the extracellular fluid.Explain the importance of water in the body.Other therapies include elevation of the affected part to assist drainage, massage and compression of the areas to move the fluid out of the tissues, and decreased salt intake to decrease sodium and water retention.By the end of this section, you will be able to: Activities that can reduce the effects of the condition include appropriate exercises to keep the blood and lymph flowing through the affected areas. Therapy for edema usually focuses on elimination of the cause. Underlying medical conditions that can contribute to edema include congestive heart failure, kidney damage and kidney disease, disorders that affect the veins of the legs, and cirrhosis and other liver disorders. Medications that can result in edema include vasodilators, calcium channel blockers used to treat hypertension, non-steroidal anti-inflammatory drugs, estrogen therapies, and some diabetes medications. Otherwise, the venous blood pools in the lower limbs and can leak into surrounding tissues. This is because deep veins in the lower limbs rely on skeletal muscle contractions to push on the veins and thus “pump” blood back to the heart. Mild, transient edema of the feet and legs may be caused by sitting or standing in the same position for long periods of time, as in the work of a toll collector or a supermarket cashier. An allergic reaction can cause capillaries in the hand to leak excess fluid that accumulates in the tissues.

Body fluid compartments usmle