The kidney uses a large amount of energy, most of which are dedicated to solute reabsorption, especially Na + , from glomerular filtrate. Reabsorption of Na + drives the cellular and paracellular transport of water and other solutes. The mechanisms…
Cells must avoid gross alterations of volume in order to survive. Obviously, excessive cell swelling will jeopardize the integrity of the cell membrane, and both cell swelling and cell shrinkage will interfere with cytoskeletal architecture. Moreover, cellular function critically depends…
In this chapter we discuss the pathways and mechanisms of water transport across cell membranes and epithelia. The concepts of diffusion and osmosis are presented at the biophysical level and applied to water transport phenomena across lipid bilayers and membrane-spanning…
Ion motive ATPases involved in transcellular ion transport by renal epithelial cells include two molecular families: P-ATPases (Na,K-ATPase and H,K-ATPase) and V-ATPases. Na,K-ATPase is found in the plasma membrane of every vertebrate cell and exchanges three intracellular Na + for…
Ion transport across the cell membrane is essential to maintain the composition of the intracellular milieu . This chapter provides an introduction to ion transport processes in the cell membrane. The cell membrane is a thin sheet containing lipids (phospholipid…
Few cell types more elegantly embody the dictum that “form follows function” than do those of polarized epithelia. It is the unique architecture of renal epithelial cells that permits them to mediate vectorial transport. This transport, in turn, essentially determines…
Chapter 1 1. c 2. e 3. a 4. d 5. c Chapter 2 1. b 2. e 3. c 4. e 5. a 6. b 7. c 8. b 9. d 10. e Chapter 3 1. a 2. b…
Chapter 1 1. A healthy individual weighs 50 kg. What is the volume of this individual’s extracellular fluid compartment? a. 2.5 L b. 7.5 L c. 10.0 L d. 20.0 L e. 30.0 L 2. A healthy individual loses body…
Case 1 1a. The ECF volume of this man is increased above normal. The presence of edema, distention of the neck veins, and rales (sounds related to fluid in the lungs) is evidence of this increased volume. Additional evidence could…
Chapter 1 1. Molarity (mmol/L) Osmolality (mOsm/kg H 2 O) 9 g NaCl 154 308 72 g Glucose 400 400 22.2 g CaCl 2 200 600 3 g Urea 50 50 8.4 g NaHCO 3 100 200 2. The cell…