Question

What mechanism ultimately provides the force that reabsorbs the materials from the proximal convoluted tubules?

	a.	diffusion powered by body heat
	b.	osmosis
	c.	sodium-potassium (Na+/K+) pumps, powered by the breakdown of ATP
	d.	pinocytosis

he membranes of which of the following are impermeable to water?

	a.	the glomerulus
	b.	the proximal convoluted tubules
	c.	the descending nephron loop
	d.	the ascending nephron loop

Which of the following would cause an increase in urine output?

	a.	a decrease in blood pressure
	b.	an increase in glucose concentration in the urine in the collecting tubules
	c.	an decrease in plasma glucose concentration
	d.	an increase in Na+ transport out of the ascending nephron loop

Which of the following chains of causes and effects is correct?

	a.	decrease in blood pressure –> secretion of ADH –> increase in water reabsorption –> increase in blood pressure
	b.	increase in blood pressure –> secretion of ADH –> increase in water reabsorption –> increase in blood pressure
	c.	increase in blood pressure –> secretion of ADH –> decrease in water reabsorption –> increase in blood pressure
	d.	decrease in blood pressure –> secretion of ADH –> decrease in water reabsorption –> increase in blood pressure

Which of the following is not a passive immune defense?

	a.	dead, dry skin
	b.	mucus coatings of membranes in the stomach lining and elsewhere
	c.	production of antibodies by B lymphocytes
	d.	lysozyme in tears and saliva

Answer 1

-Sodium-potassium pumps help reabsorb nutrients from the proximal convoluted tubules.

-The ascending nephron loop is impermeable to water.

-An increase in glucose concentration in urine in collecting tubules, would lead to increased urine output. High glucose is generally because of diabetes mellitus.

-Decreased blood pressure stimulates ADH release, which increases water reabsorption, thus increasing the blood pressure.

-Production of antibodies is an active immune defense.