sodium

DEFINITION:

A silver white soft waxy ductile element of the alkali metal group that occurs abundantly in nature in combined form and is very active chemically.

organisms

DEFINITION:

Individual living things, whether animals or plants.

reabsorption

DEFINITION:

The act or process of absorbing again, as the selective absorption by the kidneys of substances (glucose, proteins, sodium, etc.) already secreted into the renal tubules, and their return to the circulating blood.

sodium

DEFINITION:

A silver white soft waxy ductile element of the alkali metal group that occurs abundantly in nature in combined form and is very active chemically.

tubule

DEFINITION:

A small tube.

arcuate renal tubule - A short, curved part of the distal end of the renal tubule (See below), extending from the distal convoluted tubule (See below) to the straight collecting tubule (See below). Called also junctional (connecting) tubule .

collecting tubule - A channel through which fluids pass from the secreting cells.

connecting tubule - Arcuate renal tubule (See above).

distal convoluted tubule - A distal, rolled-together or coiled part of the ascending limb of the renal tubule (See below), extending from the distal straight tubule (See below) to the junctional (connecting) tubule (See below).

distal straight tubule - Part of the renal tubule (See below) primarily on the ascending limb, extending from the thin tubule (See below) to the distal convoluted tubule (See above).

junctional (connecting) tubule - See arcuate renal tubule (above).

proximal convoluted tubule - The most proximal part of the renal tubule (See below), extending from the glomerular capsule to the proximal straight tubule (See below).

proximal straight tubule - Part of the descending limb of the renal tubule (See below), extending from the thin tubule (See below) to the distal convoluted tubule (See above).

renal collecting tubule - The arcuate renal tubule (See above), straight collecting tubule (See below), and papillary duct considered together. Called also collecting duct .

renal tubule - One of the minute, reabsorptive, secretory, and collecting canals, made up of basement membrane lined with epithelium, that form the substance of the kidneys. See also nephron .

straight collecting tubule - The lower straight part of the renal collecting tubule (See above), extending from the arcuate renal tubule (See above) to the papillary duct.

thin tubule - Part of the renal tubule (See above) at the lower end where the walls are especially thin; it extends from the proximal straight tubule (See above) to the distal straight tubule (See above). In juxtamedullary and deep cortical nephrons it makes up most of the length of Henle's loop.

nephron

DEFINITION:

The anatomical and functional unit of the kidney, consisting of the renal corpuscle, the proximal convoluted tubule, the descending and ascending limbs of Henle's loop, the distal convoluted tubule, and the collecting tubule.

functional

DEFINITION:

1. Of or pertaining to a function.

2. Affecting the function but not the structure.

kidney

DEFINITION:

One of a pair of vertebrate organs situated in the body cavity near the spinal column that excrete waste products of metabolism, in man are bean-shaped organs about 4-1/2 inches long lying behind the peritoneum in a mass of fatty tissue, and consist chiefly of nephrons by which urine is secreted, collected, and discharged into a main cavity whence it is conveyed by the ureter to the bladder.

transport

DEFINITION:

The movement of materials in biological systems, particularly into and out of cells and across epithelial layers.

altered

DEFINITION:

1. Having been made or become different.

2. Castrated; spayed.

3. Abbreviation for "alteration."

transport protein

DEFINITION:

See under proteins .

metabolic alkalosis

DEFINITION:

A disturbance in which the acid-base status of the body shifts toward the alkaline side because of retention of base or loss of noncarbonic, or fixed (nonvolatile), acids.

hypokalemia

DEFINITION:

Abnormally low potassium concentration in the blood; it may result from excessive potassium loss by the renal or the gastrointestinal route, from decreased intake, or from transcellular shifts. It may be manifested clinically by neuromuscular disorders ranging from weakness to paralysis, by electrocardiographic abnormalities (depression of the T wave and elevation of the U wave), by renal disease, and by gastrointestinal disorders.

hypertension

DEFINITION:

Abnormally high blood pressure and especially arterial blood pressure.

capacity

DEFINITION:

1. Power or ability to hold, retain, or contain, or the ability to absorb.

2. The volume or potential volume of material (solid, liquid, or gas) that can be held or contained.

3. Capacitance.

4. Mental ability to receive, accomplish, endure, or understand.

concentrate

DEFINITION:

1. To bring to a common center; to gather together at one point.

2. To increase the strength by diminishing the bulk of, as of a liquid; to condense.

3. A drug or other preparation that has been strengthened by the evaporation of its non-active parts.

urine

DEFINITION:

The fluid excreted by the kidneys, passed through the ureters, stored in the bladder, and discharged through the urethra. Urine, in health, has an amber color, a slight acid reaction, a peculiar odor, and a bitter, saline taste.

molecular

DEFINITION:

Of, pertaining to, or composed of molecules.

molecular

DEFINITION:

Of, pertaining to, or composed of molecules.

Bartter's syndrome

DEFINITION:

Hypertrophy and hyperplasia of the juxtaglomerular cells, producing hypokalemic alkalosis and hyperaldosteronism, characterized by absence of hypertension in the presence of markedly increased plasma renin concentrations, and by insensitivity to the pressor effects of angiotensin. It usually affects children, may be hereditary, and may be associated with other anomalies such as mental retardation and short stature. Called also juxtaglomerular cell hyperplasia.

Gitelman's syndrome

DEFINITION:

A syndrome of hypertrophy of juxtaglomerular cells similar to Bartter's syndrome but with hypocalciuria and hypomagnesemia; usually seen in adolescents or adults.

Liddle's syndrome

DEFINITION:

A rare autosomal dominant syndrome characterized by hypertension with excessive renal reabsorption of sodium, depletion of potassium, and low activity of renin and aldosterone.

autosomal nephrogenic diabetes insipidus

DEFINITION:

Nephrogenic diabetes insipidus involving an ordinary paired chromosome that is alike in males and females, as distinguished from sex chromosomes (i.e., as distinguished from X-linked nephrogenic diabetes insipidus).

molecular

DEFINITION:

Of, pertaining to, or composed of molecules.

disorders

DEFINITION:

Derangements or abnormalities of function; morbid physical or mental states.

kidney

DEFINITION:

One of a pair of vertebrate organs situated in the body cavity near the spinal column that excrete waste products of metabolism, in man are bean-shaped organs about 4-1/2 inches long lying behind the peritoneum in a mass of fatty tissue, and consist chiefly of nephrons by which urine is secreted, collected, and discharged into a main cavity whence it is conveyed by the ureter to the bladder.

renal function

DEFINITION:

Kidney function.

vertebrates

DEFINITION:

1. Having a vertebral column.
2. Members of the subphylum Vertebrata.