cerebrospinal fluid

fluid /flu·id/ (floo´id)

1. a liquid or gas; any liquid of the body.

2. composed of molecules which freely change their relative positions without separation of the mass.

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amniotic fluid  the liquid within the amnion that bathes the developing fetus and protects it from mechanical injury.

cerebrospinal fluid  (CSF) the fluid contained within the ventricles of the brain, the subarachnoid space, and the central canal of the spinal cord.

follicular fluid  the fluid in a developing ovarian follicle.

interstitial fluid  the extracellular fluid bathing most tissues, excluding the fluid within the lymph and blood vessels.

intracellular fluid  the portion of the total body water with its dissolved solutes which are within the cell membranes.

prostatic fluid  the secretion of the prostate gland, which contributes to formation of the semen.

Scarpa's fluid  endolymph.

seminal fluid  semen.

synovial fluid  synovia; the transparent, viscid fluid secreted by the synovial membrane and found in joint cavities, bursae, and tendon sheaths.

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cerebrospinal fluid

n. Abbr. CSF

The serumlike fluid that circulates through the ventricles of the brain, the cavity of the spinal cord, and the subarachnoid space, functioning as a shock absorber. Also called spinal fluid.

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Cerebrospinal fluid (CSF)

Fluid produced within the brain for nutrient transport and structural purposes. CSF circulates through the ventricles, open spaces within the brain, and drains through the membranes surrounding the brain.

Mentioned in: Brain Tumor, Central Nervous System Infections, Congenital Brain Defects, Cryptococcosis, Hydrocephalus, Lyme Disease, Ophthalmoplegia, Subarachnoid Hemorrhage, Ventricular Shunt

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cerebrospinal fluid (CSF),

the fluid that flows through and protects the four ventricles of the brain, the subarachnoid spaces, and the spinal canal. It is composed mainly of secretions of the choroid plexuses in the lateral ventricles and in the third and the fourth ventricles of the brain and is clear and colorless. Changes in the carbon dioxide content of CSF affect the respiratory center in the medulla, helping to control breathing. A brain tumor may press against the cerebral aqueduct and shut off the flow of the fluid from the third to the fourth ventricle, causing fluid accumulation in the lateral and third ventricles, called internal hydrocephalus. Other blockages of the flow of CSF, such as those caused by blood clots, result in serious complications. Certain illnesses and various diagnoses may require microscopic examination and chemical analysis of CSF. Samples of the fluid may be removed by lumbar puncture between the third and the fourth lumbar vertebrae or from the cisterna magna.

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cerebrospinal [ser″ĕ-bro-spi´nal]

pertaining to the brain and spinal cord.

cerebrospinal fluid the fluid within the subarachnoid space, the central canal of the spinal cord, and the four ventricles of the brain. The fluid is formed continuously by the choroid plexus in the ventricles, and, so that there will not be an abnormal increase in amount and pressure, it is reabsorbed into the blood by the arachnoid villi at approximately the same rate at which it is produced.

The cerebrospinal fluid aids in the protection of the brain, spinal cord, and meninges by acting as a watery cushion surrounding them to absorb the shocks to which they are exposed. There is a blood-cerebrospinal fluid barrier that prevents harmful substances, such as metal poisons, some pathogenic organisms, and certain drugs from passing from the capillaries into the cerebrospinal fluid.

The normal cerebrospinal fluid pressure is 5 mm Hg (100 mm H₂O) when the individual is lying in a horizontal position on his side. Fluid pressure may be increased by a brain tumor or by hemorrhage or infection in the cranium. hydrocephalus, or excess fluid in the cranial cavity, can result from either excessive formation or poor absorption of cerebrospinal fluid. Blockage of the flow of fluid in the spinal canal may result from a tumor, blood clot, or severance of the spinal cord. The pressure remains normal or decreases below the point of obstruction but increases above that point.

Cell counts, bacterial smears, and cultures of samples of cerebrospinal fluid are done when an inflammatory process or infection of the meninges is suspected. Since the cerebrospinal fluid contains nutrient substances such as glucose, proteins, and sodium chloride, and also some waste products such as urea, it is believed to play a role in metabolism. The major constituents of cerebrospinal fluid are water, glucose, sodium chloride, and protein. Information about changes in their concentrations is helpful in diagnosis of brain diseases.

Samples of cerebrospinal fluid may be obtained by lumbar puncture, in which a hollow needle is inserted between two lumbar vertebrae (below the lower end of the spinal cord), or into the cisterna cerebellomedullaris just below the occipital bone of the skull (cisternal puncture). Pressure of the cerebrospinal fluid is measured by a manometer attached to the end of the needle after it has been inserted.

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cerebrospinal fluid (s·rēˈ·brō·spīˑ·nl flōōˑ·id),

n colorless, clear fluid that surrounds the central nervous system, that absorbs shocks, delivers nutrients, and removes waste products.

Cerebrospinal fluid.

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cerebrospinal fluid,

n the fluid that flows through and protects the four ventricles of the brain, subarachnoid space, and spinal canal.

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fluid

1. a liquid or gas; any liquid of the body.

2. composed of molecules which freely change their relative positions without separation of the mass.

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allantoic fluid

the fluid contained within the allantois.

amniotic fluid

the fluid within the amnion that bathes the developing fetus and protects it from mechanical injury.

ascitic fluid

see ascites.

fluid balance

a state in which the volume of body water and its solutes (electrolytes and nonelectrolytes) are within normal limits and there is normal distribution of fluids within the intracellular and extracellular compartments. The total volume of body fluids should be about 60% of the body weight, and it should be distributed so that one-third is extracellular fluid and two-thirds intracellular fluid. Although this distribution remains constant in a healthy animal, there is continuous movement of fluid into and out of the various compartments. See also dehydration, water intoxication.

body f's

the fluids within the body, composed of water, electrolytes and nonelectrolytes. The volume and distribution of body fluids vary with age, sex and amount of adipose tissue. Throughout life there is a slow decline in the volume of body fluids; obesity decreases the relative amount of water in the body.

Although the body fluids are continuously in motion, moving in and out of the cells, tissue spaces and vascular system, physiologists consider them to be 'compartmentalized'. Fluid within the cell membranes is called intracellular fluid and comprises about two-thirds of the total body fluids. The remaining one-third is outside the cell and is called extracellular fluid. The extracellular fluid can be further divided into tissue fluid (interstitial fluid), which is found in the spaces between the blood vessels and surrounding cells, and intravascular fluid, which is the fluid component of blood.

The maintenance of a proper balance between the intracellular and extracellular fluid volumes is essential to health. In patients with heart failure and renal failure the balance becomes upset, producing either localized or generalized edema. Excessive fluid loss produces fluid volume deficit causing cellular dehydration and impaired cellular function.

Bouin's fluid

a histological fixative.

cerebrospinal fluid

the fluid contained within the ventricles of the brain, the subarachnoid space, and the central canal of the spinal cord. See also cerebrospinal fluid.

fluid dram

see fluid dram.

fluid extract

a liquid preparation of a vegetable drug, containing alcohol as a solvent or preservative, or both, of such strength that each milliliter contains the therapeutic constituents of 1 gram of the standard drug it represents.

fetal fluid

allantoic plus amniotic fluids.

interstitial fluid

the extracellular fluid bathing the cells in most tissues, excluding the fluid within the lymph and blood vessels.

isotonic fluid

having the same tonicity or osmotic pressure as blood.

lacrimal fluid

aqueous fluid secreted by the lacrimal glands; called also tears.

fluid line

in radiographs, the interface between fluid and gas, as in the gastrointestinal tract, will show as a straight line.

fluid loss

by vomiting, diarrhea, polyuria, water deprivation. See dehydration.

fluid mosaic model

the modern concept of the structure of a biological membrane developed by S.J. Singer and G.L. Nicolson. In it the membrane consists of protein molecules partly embedded in a discontinuous bilayer of phospholipids that form the matrix of a mosaic of functional cell units.

fluid ounce

see fluid ounce.

pericardial, pleural, peritoneal fluid

normally present in amounts sufficient only to lubricate the movement of viscera within the respective cavities. Composition similar to blood serum.

fluid replacement

see fluid therapy (below).

fluid restriction

the limitation of oral fluid intake to a prescribed amount for each 24-hour period.

fluid retention

see edema.

spinal fluid

the fluid within the spinal canal.

fluid splashing sounds

audible when gas and fluid are free in a cavity, e.g. abomasum in cases of abomasal displacement; can be elicited by shaking a small animal or part of a large animal (i.e. succussion) or by simultaneous percussion and auscultation.

synovial fluid

synovia.

fluid therapy

aims to replace fluids lost by disease process or by restriction of intake, or to maintain a high rate of fluid excretion to ensure removal of toxins, or to administer therapeutic or anesthetic agents slowly over a long period. The amounts and route of administration vary with the need of the patient. Normal solutions include 5% dextrose and Ringer's solution; alkalinizing fluids include lactated Ringer's and 1.3% sodium bicarbonate; acidifying solutions include isotonic saline and 1.9% ammonium chloride.

fluid thrill

see thrill.

fluid volume deficit

an imbalance in fluid volume in which there is loss of fluid from the body not compensated for by an adequate intake of water. The major causes are: (1) insufficient fluid intake, and (2) excessive fluid loss from vomiting, diarrhea, suctioning of gastric contents, or drainage through operative wounds, burns or fistulae. Decreased volume in the intravascular compartment is called hypovolemia. Because water moves freely between the compartments, extracellular fluid deficit causes intracellular fluid deficit (cellular dehydration), which leaves the cells without adequate water to carry on normal function.

fluid volume excess

an overabundance of water in the interstitial fluid spaces or body cavities (edema) or an excess of fluid within the blood vessels (hypervolemia) and water intoxication.

Factors that contribute to the accumulation of edematous fluid are: (1) dilatation of the arteries, as occurs in the inflammatory process; (2) reduced effective osmotic pressure, as in hypoproteinemia, lymphatic obstruction and increased capillary permeability; (3) increased venous pressure, as in congestive heart failure, thrombophlebitis and cirrhosis of the liver; and (4) retention of sodium due to increased reabsorption of sodium by the renal tubules.

fluid wave

see thrill.

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cerebrospinal fluid

Spinal fluid Neurology A clear, colorless fluid that contains small quantities of glucose and protein, which surrounds the brain, spinal cord, ventricles, subarachnoid space, and the central canal of the spinal cord, provides nutrients, and acts as a shock absorber; CSF analysis is accomplished by lumbar puncture; WBCs or bacteria in the CSF indicate bacterial–septic meningitis. See Lumbar puncture.