Describe how the vertical osmotic gradient is used to create urine of various dilutions
What will be an ideal response?
The counter current system of the loop of Henle establishes the medullary vertical osmotic gradient. The gradient can be established because the cells that make up the loop of Henle have specialized properties that allow them to move water and salts from the filtrate into the interstitial space. The gradient is used by the cells in the collecting ducts to concentrate the tubular fluid so that urine more concentrated than body fluid can be excreted. And because the fluid is hypotonic as it enters the distal portion of the tubules, the kidney can excrete urine more dilute than body fluids. The concentration of urine excreted is dependent upon the body's needs and the presence or absence of vasopressin.
You might also like to view...
Blood colloid osmotic pressure (BCOP) in the glomerulus is generated by
A) blood pressure. B) presence of albumin proteins in blood plasma. C) constriction of the efferent arteriole. D) protein in the filtrate. E) filtrate in the capsular space.
Which of the following is not true of the conditions used to measure basal metabolic rate?
A. The person is in a brightly lit room with a cool temperature. B. The person has not exercised for at least an hour. C. The person has not eaten for 12-14 hours. D. The person is awake and relaxed. E. All of these are true of the conditions used to measure basal metabolic rate.
The ________ stores excess glucose and releases it into the blood when needed.
A. liver B. spleen C. pancreas D. stomach E. small intestine
Which is one of the major inhibitory neurotransmittors in the CNS?
A. Glutamate B. Dopamine C. Norepinephrine D. Gamma-aminobutyric acid (GABA) E. Beta-endorphin