Ganong's Review of Medical Physiology, 23rd Edition

Recommendations

Info

686 SECTION VIII Renal Physiology Additional graduations on the upper curved scale of the nomogram (Figure 40–7) are provided for measuring buffer base content; the point where the CO 2 calibration line of the arterial blood sample intersects this scale shows the mEq/L of buffer base in the sample. The buffer base is equal to the total number of buffer anions (principally Prot – , HCO 3 – , and Hb – ) that can accept hydrogen ions in the blood. The normal value in an individual with 15 g of hemoglobin per deciliter of blood is 48 mEq/L. The point at which the CO 2 calibration line intersects the lower curved scale on the nomogram indicates the base excess. This value, which is positive in alkalosis and negative in acidosis, is the amount of acid or base that would restore 1 L of blood to normal acid–base composition at a PCO 2 of 40 mm Hg. It should be noted that a base deficiency cannot be completely corrected simply by calculating the difference between the normal standard bicarbonate (24 mEq/L) and the actual standard bicarbonate and administering this amount of NaHCO 3 per liter of blood; some of the added HCO 3 – is converted to CO 2 and H 2 O, and the CO 2 is lost in the lungs. The actual amount that must be added is roughly 1.2 times the standard bicarbonate deficit, but the lower curved scale on the nomogram, which has been developed empirically by analyzing many blood samples, is more accurate. In treating acid–base disturbances, one must, of course, consider not only the blood but also all the body fluid compartments. The other fluid compartments have markedly different concentrations of buffers. It has been determined empirically that administration of an amount of acid (in alkalosis) or base (in acidosis) equal to 50% of the body weight in kilograms times the blood base excess per liter will correct the acid–base disturbance in the whole body. At least when the abnormality is severe, however, it is unwise to attempt such a large correction in a single step; instead, about half the indicated amount should be given and the arterial blood acid–base values determined again. The amount required for final correction can then be calculated and administered. It is also worth noting that, at least in lactic acidosis, NaHCO 3 decreases cardiac output and lowers blood pressure, so it should be used with caution. CHAPTER SUMMARY ■ The cells of the proximal and distal tubules secrete hydrogen ions. Acidification also occurs in the collecting ducts. The reaction that is primarily responsible for H + secretion in the proximal tubules is Na + –H + exchange. Na is absorbed from the lumen of the tubule and H is excreted. ■ The maximal H + gradient against which the transport mechanisms can secrete in humans corresponds to a urine pH of about 4.5. However, three important reactions in the tubular fluid remove free H + , permitting more acid to be secreted. These are the reactions with HCO 3 – to form CO2 and H 2 O, with HPO 4 2– to form H 2 PO 4 – , and with NH3 to form NH 4 + . ■ Carbonic anhydrase catalyzes the formation of H 2 CO 3 , and drugs that inhibit carbonic anhydrase depress secretion of acid by the proximal tubules. ■ Renal acid secretion is altered by changes in the intracellular PCO 2, K + concentration, carbonic anhydrase level, and adrenocortical hormone concentration. MULTIPLE-CHOICE QUESTIONS For all questions, select the single best answer unless otherwise directed. 1. Which of the following is the principal buffer in interstitial fluid? A) hemoglobin B) other proteins C) carbonic acid D) H 2 PO 4 E) compounds containing histidine 2. Increasing alveolar ventilation increases the blood pH because A) it activates neural mechanisms that remove acid from the blood. B) it makes hemoglobin a stronger acid. C) it increases the PO 2 of the blood. D) it decreases the PCO 2 in the alveoli. E) the increased muscle work of increased breathing generates more CO 2. 3. In uncompensated metabolic alkalosis A) the plasma pH, the plasma HCO 3 – concentration, and the arterial PCO 2 are all low. B) the plasma pH is high and the plasma HCO 3 – concentration and arterial PCO 2 are low. C) the plasma pH and the plasma HCO 3 – concentration are low and the arterial PCO 2 is normal. D) the plasma pH and the plasma HCO 3 – concentration are high and the arterial PCO 2 is normal. E) the plasma pH is low, the plasma HCO 3 – concentration is high, and the arterial PCO 2 is normal. 4. In a patient with a plasma pH of 7.10, the [HCO 3 – ]/[H2 CO 3 ] ratio in plasma is A) 20. B) 10. C) 2. D) 1. E) 0.1. CHAPTER RESOURCES Adrogué HJ, Madius NE: Management of life-threatening acid–base disorders. N Engl J Med 1998;338:26. Brenner BM, Rector FC Jr. (editors): The Kidney, 6th ed. 2 vols. Saunders, 1999. Davenport HW: The ABC of Acid–Base Chemistry, 6th ed. University of Chicago Press, 1974. Halperin ML: Fluid, Electrolyte, and Acid–Base Physiology, 3rd ed. Saunders, 1998. Lemann J Jr., Bushinsky DA, Hamm LL: Bone buffering of acid and base in humans. Am J Physiol Renal Physiol 2003;285:F811. Review. Vize PD, Wolff AS, Bard JBL (editors): The Kidney: From Normal Development to Congenital Disease. Academic Press, 2003.
Answers to Multiple Choice Questions Chapter 1 1. B 2. C 3. B 4. C 5. C 6. D 7. E 8. E. Chapter 2 1. A 2. D 3. D 4. B 5. C 6. C 7. B. Chapter 3 1. C 2. E 3. B 4. C Chapter 4 1. B 2. E 3. B 4. C 5. B Chapter 5 1. B 2. D 3. B 4. C 5. C. Chapter 6 1. E 2. C 3. E 4. B Chapter 7 1. C 2. D 3. C 4. B 5. A Chapter 8 1. C 2. D 3. A 4. E 5. C 6. E 7. A Chapter 9 1. C 2. E 3. C 4. E Chapter 10 1. C 2. C 3. A 4. D Chapter 11 1. D 2. B 3. E 4. D Chapter 12 1. D 2. D 3. B 4. E 5. D 6. B 7. D 8. D Chapter 13 1. E 2. B 3. C 4. E 5. D 6. D 7. E 8. A Chapter 14 1. D 2. C 3. D 4. D 5. D 6. C 7. D 8. E Chapter 15 1. C 2. D 3. C 4. D 5. A 6. C Chapter 16 1. C 2. E 3. E 4. D 5. B 6. A Chapter 17 1. A 2. B 3. D 4. D Chapter 18 1. B 2. E 3. B 4. A 5. A 6. B 7. D 8. D Chapter 19 1. A 2. E 3. C 4. D 5. B 6. D 7. D Chapter 20 1. C 2. D 3. A 4. C 5. B 6. D 7. A 8. C 9. E Chapter 21 1. E 2. D 3. D 4. C 5. E 6. D 7. C Chapter 22 1. D 2. B 3. E 4. D 5. C 6. D 7. D 8. A 9. A Chapter 23 1. C 2. E 3. D 4. A 5. C 6. D 7. E Chapter 24 1. E 2. E 3. A 4. C 5. B 687
Page 2 and 3:
Ranges of Normal Values in Human Wh
Page 4 and 5:
Copyright © 2010 by The McGraw-Hil
Page 6 and 7:
iv Key Features of the 23rd Edition
Page 8 and 9:
About the Authors KIM E. BARRETT Ki
Page 10 and 11:
viii CONTENTS 27. Digestion, Absorp
Page 12 and 13:
This page intentionally left blank
Page 14 and 15:
2 SECTION I Cellular & Molecular Ba
Page 16 and 17:
Page 18 and 19:
Page 20 and 21:
Page 22 and 23:
10 SECTION I Cellular & Molecular B
Page 24 and 25:
Page 26 and 27:
Page 28 and 29:
Page 30 and 31:
Page 32 and 33:
Page 34 and 35:
Page 36 and 37:
Page 38 and 39:
Page 40 and 41:
Page 42 and 43:
Page 44 and 45:
Page 46 and 47:
Page 48 and 49:
Page 50 and 51:
Page 52 and 53:
Page 54 and 55:
Page 56 and 57:
Page 58 and 59:
Page 60 and 61:
Page 62 and 63:
Page 64 and 65:
Page 66 and 67:
Page 68 and 69:
Page 70 and 71:
Page 72 and 73:
Page 74 and 75:
Page 76 and 77:
Page 78 and 79:
Page 80 and 81:
Page 82 and 83:
Page 84 and 85:
Page 86 and 87:
Page 88 and 89:
Page 90 and 91:
Page 92 and 93:
80 SECTION II Physiology of Nerve &
Page 94 and 95:
Page 96 and 97:
Page 98 and 99:
Page 100 and 101:
Page 102 and 103:
Page 104 and 105:
Page 106 and 107:
Page 108 and 109:
Page 110 and 111:
Page 112 and 113:
100 SECTION II Physiology of Nerve
Page 114 and 115:
Page 116 and 117:
Page 118 and 119:
Page 120 and 121:
Page 122 and 123:
Page 124 and 125:
Page 126 and 127:
Page 128 and 129:
Page 130 and 131:
Page 132 and 133:
Page 134 and 135:
Page 136 and 137:
Page 138 and 139:
Page 140 and 141:
Page 142 and 143:
Page 144 and 145:
Page 146 and 147:
Page 148 and 149:
Page 150 and 151:
Page 152 and 153:
Page 154 and 155:
Page 156 and 157:
Page 158 and 159:
Page 160 and 161:
Page 162 and 163:
Page 164 and 165:
Page 166 and 167:
Page 168 and 169:
Page 170 and 171:
Page 172 and 173:
Page 174 and 175:
Page 176 and 177:
Page 178 and 179:
Page 180 and 181:
168 SECTION III Central & Periphera
Page 182 and 183:
Page 184 and 185:
Page 186 and 187:
Page 188 and 189:
Page 190 and 191:
Page 192 and 193:
Page 194 and 195:
Page 196 and 197:
Page 198 and 199:
Page 200 and 201:
Page 202 and 203:
Page 204 and 205:
Page 206 and 207:
Page 208 and 209:
Page 210 and 211:
Page 212 and 213:
Page 214 and 215:
Page 216 and 217:
Page 218 and 219:
Page 220 and 221:
Page 222 and 223:
Page 224 and 225:
Page 226 and 227:
Page 228 and 229:
Page 230 and 231:
Page 232 and 233:
Page 234 and 235:
Page 236 and 237:
Page 238 and 239:
Page 240 and 241:
Page 242 and 243:
Page 244 and 245:
Page 246 and 247:
Page 248 and 249:
Page 250 and 251:
Page 252 and 253:
Page 254 and 255:
Page 256 and 257:
Page 258 and 259:
Page 260 and 261:
Page 262 and 263:
Page 264 and 265:
Page 266 and 267:
Page 268 and 269:
Page 270 and 271:
Page 272 and 273:
Page 274 and 275:
Page 276 and 277:
Page 278 and 279:
Page 280 and 281:
Page 282 and 283:
Page 284 and 285:
Page 286 and 287:
Page 288 and 289:
Page 290 and 291:
Page 292 and 293:
Page 294 and 295:
Page 296 and 297:
Page 298 and 299:
Page 300 and 301:
Page 302 and 303:
Page 304 and 305:
Page 306 and 307:
Page 308 and 309:
Page 310 and 311:
Page 312 and 313:
Page 314 and 315:
302 SECTION IV Endocrine & Reproduc
Page 316 and 317:
Page 318 and 319:
Page 320 and 321:
Page 322 and 323:
Page 324 and 325:
Page 326 and 327:
Page 328 and 329:
Page 330 and 331:
Page 332 and 333:
Page 334 and 335:
Page 336 and 337:
Page 338 and 339:
Page 340 and 341:
Page 342 and 343:
Page 344 and 345:
Page 346 and 347:
Page 348 and 349:
Page 350 and 351:
Page 352 and 353:
Page 354 and 355:
Page 356 and 357:
Page 358 and 359:
Page 360 and 361:
Page 362 and 363:
Page 364 and 365:
Page 366 and 367:
Page 368 and 369:
Page 370 and 371:
Page 372 and 373:
Page 374 and 375:
Page 376 and 377:
Page 378 and 379:
Page 380 and 381:
Page 382 and 383:
Page 384 and 385:
Page 386 and 387:
Page 388 and 389:
Page 390 and 391:
Page 392 and 393:
Page 394 and 395:
Page 396 and 397:
Page 398 and 399:
Page 400 and 401:
Page 402 and 403:
Page 404 and 405:
Page 406 and 407:
Page 408 and 409:
Page 410 and 411:
Page 412 and 413:
Page 414 and 415:
Page 416 and 417:
Page 418 and 419:
Page 420 and 421:
Page 422 and 423:
Page 424 and 425:
Page 426 and 427:
Page 428 and 429:
Page 430 and 431:
Page 432 and 433:
Page 434 and 435:
Page 436 and 437:
Page 438 and 439:
Page 440 and 441:
Page 442 and 443:
430 SECTION V Gastrointestinal Phys
Page 444 and 445:
Page 446 and 447:
Page 448 and 449:
Page 450 and 451:
Page 452 and 453:
Page 454 and 455:
Page 456 and 457:
Page 458 and 459:
Page 460 and 461:
Page 462 and 463:
Page 464 and 465:
Page 466 and 467:
Page 468 and 469:
Page 470 and 471:
Page 472 and 473:
Page 474 and 475:
Page 476 and 477:
Page 478 and 479:
Page 480 and 481:
Page 482 and 483:
Page 484 and 485:
Page 486 and 487:
Page 488 and 489:
Page 490 and 491:
Page 492 and 493:
Page 494 and 495:
Page 496 and 497:
Page 498 and 499:
Page 500 and 501:
Page 502 and 503:
490 SECTION VI Cardiovascular Physi
Page 504 and 505:
Page 506 and 507:
Page 508 and 509:
Page 510 and 511:
Page 512 and 513:
Page 514 and 515:
Page 516 and 517:
Page 518 and 519:
Page 520 and 521:
Page 522 and 523:
Page 524 and 525:
Page 526 and 527:
Page 528 and 529:
Page 530 and 531:
Page 532 and 533:
Page 534 and 535:
Page 536 and 537:
Page 538 and 539:
Page 540 and 541:
Page 542 and 543:
Page 544 and 545:
Page 546 and 547:
Page 548 and 549:
Page 550 and 551:
Page 552 and 553:
Page 554 and 555:
Page 556 and 557:
Page 558 and 559:
Page 560 and 561:
Page 562 and 563:
Page 564 and 565:
Page 566 and 567:
Page 568 and 569:
Page 570 and 571:
Page 572 and 573:
Page 574 and 575:
Page 576 and 577:
Page 578 and 579:
Page 580 and 581:
Page 582 and 583:
Page 584 and 585:
Page 586 and 587:
Page 588 and 589:
Page 590 and 591:
Page 592 and 593:
Page 594 and 595:
Page 596 and 597:
Page 598 and 599:
Page 600 and 601:
588 SECTION VII Respiratory Physiol
Page 602 and 603:
Page 604 and 605:
Page 606 and 607:
Page 608 and 609:
Page 610 and 611:
Page 612 and 613:
Page 614 and 615:
Page 616 and 617:
Page 618 and 619:
Page 620 and 621:
Page 622 and 623:
Page 624 and 625:
Page 626 and 627:
Page 628 and 629:
Page 630 and 631:
Page 632 and 633:
Page 634 and 635:
Page 636 and 637:
Page 638 and 639:
Page 640 and 641:
Page 642 and 643:
Page 644 and 645:
Page 646 and 647:
Page 648 and 649: 636 SECTION VII Respiratory Physiol
Page 650 and 651: 638 SECTION VII Respiratory Physiol
Page 652 and 653: 640 SECTION VIII Renal Physiology T
Page 654 and 655: 642 SECTION VIII Renal Physiology m
Page 656 and 657: 644 SECTION VIII Renal Physiology F
Page 658 and 659: 646 SECTION VIII Renal Physiology N
Page 662 and 663: 650 SECTION VIII Renal Physiology G
Page 664 and 665: 652 SECTION VIII Renal Physiology t
Page 666 and 667: 654 SECTION VIII Renal Physiology I
Page 672 and 673: 660 SECTION VIII Renal Physiology C
Page 674 and 675: 662 SECTION VIII Renal Physiology d
Page 676 and 677: This page intentionally left blank
Page 680 and 681: 668 SECTION VIII Renal Physiology p
Page 682 and 683: 670 SECTION VIII Renal Physiology l
Page 684 and 685: 672 SECTION VIII Renal Physiology A
Page 688 and 689: 676 SECTION VIII Renal Physiology E
Page 690 and 691: 678 SECTION VIII Renal Physiology o
Page 692 and 693: 680 SECTION VIII Renal Physiology I
Page 694 and 695: 682 SECTION VIII Renal Physiology C
Page 696 and 697: 684 SECTION VIII Renal Physiology A
Page 700 and 701: 688 Answers to Multiple Choice Ques
Page 702 and 703: 690 INDEX Angiotensin III, 671 Angi
Page 704 and 705: 692 INDEX Cannabinoids, 145, 179 Ca
Page 706 and 707: 694 INDEX Climbing fibers, 255 Clin
Page 708 and 709: 696 INDEX Endocrine functions of pa
Page 710 and 711: 698 INDEX Flaccid paralysis, 244 Fl
Page 712 and 713: 700 INDEX Hearing (continued) affer
Page 714 and 715: 702 INDEX Intrinsic system, 532 Int
Page 716 and 717: 704 INDEX Monoamines (continued) hi
Page 718 and 719: 706 INDEX Pacemaker (continued) imp
Page 720 and 721: 708 INDEX Proprioceptors, 632-633 P
Page 722 and 723: 710 INDEX Respiratory compensation,
Page 724 and 725: 712 INDEX Supratentorial lesions, 2
Page 726 and 727: 714 INDEX Vestibular system, 213-21
show all

Ganong's Review of Medical Physiology, 23rd Edition

Create successful ePaper yourself

Delete template?

Save as template?