Porth's Essentials of Pathophysiology Chapter 8 Exam Questions and Complete Solutions.

Porth's Essentials of Pathophysiology Chapter 8 Exam Questions and Complete Solutions Diuresis - Ans: excessive production of urine Osmoreceptors - Ans: respond to the osmolarity of the blood Baroreceptors - Ans: Receptors that respond to pressure-induced stretch of vessel walls. List the different fluid compartments - Ans: Intracellular and extracelluar (includes interstitial, plasma, and transcellular) Tonicity - Ans: The tension that the effective osmotic pressure of a solution with impermeable solutes exerts on cell a because of water movement across a cell membrane. How does a hypotonic solution affect cells? - Ans: Causes swelling How does a hypertonic solution affect cells? - Ans: Causes crenation (shrinking) How does an isotonic solution affect cells? - Ans: They stay the same size. What are the four causes of edema? - Ans: Increased capillary pressure, decreased colloidal osmotic pressure, increased capillary permeability, and obstruction of lymphatic flow. What are the three forms of extra cellular calcium in the body? - Ans: Protein bound, free, and complexed. What are the three main mechanisms of pH regulation? - Ans: The chemical buffer system, the lungs (CO2 elimination), and the kidneys (eliminate H+ and reabsorb + make more HCO3-) Diffusion - Ans: Movement of charged or uncharged particles along a concentration gradient. Osmosis - Ans: Movement of water across a semipermeable membrane. Describe the factors that control capillary fluid exchange between the vascular and interstitial fluid compartments - Ans: 1. Capillary filtration pressure: pushes water out of the capillary and into interstitial. 2. Capillary colloidal osmotic pressure: pulls water back into capillary. 3. Interstitial hydrostatic pressure: oppose movement of water outside capillary. 4. Tissue colloidal osmotic pressure: pulls water out of capillary into interstitial. What is third spacing? - Ans: The accumulation of ECF in the interstitial space (often transcellular space eg. pericardial sac, peritoneal cavity, pleural cavity) Hypodipsia - Ans: Decrease in the ability to sense thirst often associated with cerebral lesions in the hypothalamus. Polydipsia - Ans: excessive thirst