brain control of body fluid compartments

This fluid volume tends to be very stable, because the amount of water in living cells is closely regulated. The ICF makes up about 60 percent of the total water in the human body, and in an average-size adult male, the ICF accounts for about 25 liters (seven gallons) of fluid ( Figure 3). The ICF lies within cells and is the principal component of the cytosol/cytoplasm. Materials travel between cells and the plasma in capillaries through the IF. Blood plasma is the second part of the ECF. The interstitial fluid (IF) is part of the extracellular fluid (ECF) between the cells. The intracellular fluid (ICF) is the fluid within cells. Extracellular fluid has two primary constituents: the fluid component of the blood (called plasma) and the interstitial fluid (IF) that surrounds all cells not in the blood ( Figure 2). Extracellular fluid (ECF) surrounds all cells in the body. The intracellular fluid (ICF) compartment is the system that includes all fluid enclosed in cells by their plasma membranes. Fluid Compartmentsīody fluids can be discussed in terms of their specific fluid compartment, a location that is largely separate from another compartment by some form of a physical barrier. Water content varies in different body organs and tissues, from as little as 8 percent in the teeth to as much as 85 percent in the brain.

Water Content of the Body’s Organs and Tissues. In contrast, teeth have the lowest proportion of water, at 8–10 percent. 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 1). Human beings are mostly water, ranging from about 75 percent of body mass in infants to about 50–60 percent in adult men and women, 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 to regions of lower concentration, 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 and 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.

Describe the electrolyte composition of the three major fluid compartments in the body.

Specify the three primary fluid compartments of the body.

Because both acute and chronic dehydration are associated with physiological stresses, such as exercise and sustained exposure to microgravity, the present research will aid in achieving a better understanding of how vital information is handled by the nervous system for maintenance of the body's fluid matrix which is critical for health and well-being.By the end of this section, you will be able to: Over recent years, our laboratory has generated a substantial body of information indicating that: (1) a fall in systemic arterial pressure facilitates the ingestion of rehydrating solutions and (2) that the actions of brain amine systems (e.g., norepinephrine serotonin) are critical for precise correction of fluid losses. That is, in the face of loss of fluids from intracellular or extracellular fluid compartments, animals seek and ingest water and ionic solutions (particularly Na(+) solutions) to restore the intracellular and extracellular spaces. Neural control mechanisms and body fluid homeostasis The goal of the proposed research was to study the nature of afferent signals to the brain that reflect the status of body fluid balance and to investigate the central neural mechanisms that process this information for the activation of response systems which restore body fluid homeostasis.

Brain control of body fluid compartments