Ganong's Medical Physiology Chapter 1

extracellular fluid

The cells that make up the bodies of all but the simplest multicellular animals, both aquatic and terrestrial, exist in an “internal sea” of

interstitial fluid, blood plasma, lymph fluid

the ECF is divided into the

interstitial fluid

part of the ECF that is outside the vascular and lymph systems, bathing the cells

total blood volume

The plasma and the cellular elements of the blood, principally red blood cells, fill the vascular system, and together they constitute the

buffering capacity

Body pH i stabilized by the __ of the body fluids.

buffer

a substance that has the ability to bind or release H+ in solution, thus keeping the pH of the solution relatively constant despite the addition of considerable quantities of acid or base.

isohydric principle

All buffer pairs in a homogenous solution are in equilibrium with the same [H+ ];

diffusion

process by which a gas or a substance in a solution expands or moves from a region to another, because of the motion of its particles, to fill all the available volume

osmosis

the diffusion of solvent molecules into a region in which there is a higher concentration of a solute to which the membrane is impermeable

osmotic pressure

The pressure necessary to prevent solvent migration is the ___ of the solution

osmolarity

number of osmoles per liter of solution

osmolality

number of osmoles per kilogram of solvent; affected by volume and temperature

osmotic presure, hydrostatic pressure, water concentration, temperature, osmolality

factors affecting osmosis

tonicity

describe the osmolality of a solution relative to plasma

isotonic

Solutions that have the same osmolality as plasma are said to

hypertonic

Solutions that have greater osmolality as plasma are said to

hypotonic

Solutions that have lesser osmolality as plasma are said to

nonionic diffusion

if molecules of the undissociated substance diffuse from one side of the membrane to the other and then dissociate, there is appreciable net movement of the undissociated substance from one side of the membrane to the other

donnan effect

When an ion on one side of a membrane cannot diffuse through the membrane, the distribution of other ions to which the membrane is permeable is affected in a predictable way

oxidation

combination of a substance with O2 , or loss of hydrogen, or loss of electrons

nucleotide

When inorganic phosphate is added to the nucleside, a __ is formed