A portion of Na+ reabsorption in the late portion of the proximal tubule is passive through the paracellular pathway. What is the primary driving force for this passive reabsorption of Na+?

A. a lower luminal than peritubular hydrostatic pressure
B. a higher luminal than peritubular [Na+]
C. a lumen-positive transepithelial voltage
D. a lower interstitial fluid than luminal fluid oncotic pressure


ANS: C

Anatomy & Physiology

You might also like to view...

__________ are chemical messengers secreted in the bloodstream and stimulate physiological responses in distant organs.

Fill in the blank(s) with the appropriate word(s).

Anatomy & Physiology

Which of the following is not a function of the liver?

a. metabolic processing of carbohydrates, proteins, and fats. b. secretion of proteolytic digestive enzymes. c. detoxification and/or degradation of body wastes, hormones, drugs, and foreign compounds. d. synthesis of plasma proteins essential to the clotting process. e. storage of glycogen, fats, iron, copper, and many vitamins.

Anatomy & Physiology

Which of the following sits atop the kidneys?

A) urethra B) kidneys C) ureters D) suprarenal glands E) urinary bladder

Anatomy & Physiology

If a male has his testes removed following testicular cancer, which of the following is likely to occur?

A. Increased inhibin production B. Decreased FSH/LH secretion C. Increased levels of GnRH D. Increased testosterone production

Anatomy & Physiology