Physiology of Excretory Systems

Transcription

1 Physiology of Excretory Systems

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3 Fig 12-2 (a) Urea is formed by the ornithine-urea cycle in most vertebrates. Because ATP is required for the first step, nitrogen excretion in ureotelic animals is more energetically expensive than in other animals.

4 Fig 12-2 (b) The uricolytic pathway produces both uric acid and urea. Uric acid arises from a purine ring that is synthesized by a complex union of aspartic acid, formic acid, glycine, and CO 2. Humans lack the enzymes needed to break down uric acid and thus excrete uric acid as the end product of nucleic acid metabolism.

5 Fig 12.3 Schematic of the principal functions of a tubular excretory organ, such as the vertebrate nephron: filtration, secretion, and reabsorption.

6 Fig 12.4 Perfusion of an isolated segment of a renal tubule.

7 Fig 12.5 (a)general schematic for the organization of the protonephridia in a triclad flatworm Dendrocoelum and the detailed structure of a single protonephridium and its flame cell.

8 Fig 12.5 (b) the head region of a crustacean and the location and arrangement of the antennal gland.

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10 Fig 12.7 A nephron in a mammalian kidney.

11 Fig 12.8 Comparison of juxtamedullary and cortical nephrons.(mammalian kidney)

12 Fig 12.9 Layers of the glomerular membrane (mammailan kidney).

13 Fig Bowman s capsule podocytes with foot processes and filtration slits (mammalian kidney).

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15 Fig Adjustments of afferent arteriole caliber to alter the GFR (mammalian kidney). (a) Arteriolar adjustment to reduce the GFR.

16 Fig Adjustments of afferent arteriole caliber to alter the GFR (mammalian kidney). (b) Arteriolar adjustment to increase the GFR.

17 Fig The juxtaglomerular apparatus (mammalian kidney).

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19 Fig Baroreceptor reflex influence on the GFR in long-term regulation of arterial blood pressure (mammal).

20 Fig Change in the number of open filtration slits caused by podocyte relaxation and contration (mammalian kidney).

21 Fig Change in the number of open filtration slits caused by podocyte relaxation and contraction (mammalian kidney).

22 Table 12-2 Fate of Various Substances filtered by Mammalian kidneys. Average Percentage of Filtered Substance Reabsorbed Excreted Water 99 1 Sodium Glucose Urea (a waste product) Phenol (a waste product) Amino acids 100 0

23 Fig Steps of transepithelial transport (mammalian kidney).

24 Fig Sodium reabsorption (mammalian kidney).

25 Fig Renin-angiotensin-aldosterone system in a mammal.

26 Fig Atrial natriuretic peptide (mammal).

27 Fig Potassium secretion (mammalian kidney).

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29 Fig Plasma clearance for substances handled in different ways by mammalian kidney.

30 Fig Plasma clearance for substances handled in different ways by mammalian kidney.

31 Fig Plasma clearance for substances handled in different ways by mammalian kidney.

32 Fig Plasma clearance for substances handled in different ways by mammalian kidney.

33 Fig Vertical osmotic gradient in the human renal medulla.

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35 Fig Countercurrent multiplication in the mammalian renal medulla.

36 Fig Countercurrent multiplication in the mammalian renal medulla.

37 Fig Countercurrent multiplication in the mammalian renal medulla.

38 Fig Countercurrent multiplication in the mammalian renal medulla.

39 Fig Urea recycling in the mammalian renal medulla.

40 Fig Mechanism of action of vasopressin in a mammal.

41 Fig Excretion of urine of varying concentration depending on the mammalian body s needs (valves shown of humans).

42 Fig Excretion of urine of varying concentration depending on the mammalian body s needs (valves shown of humans).

43 Fig Countercurrent exchange in the mammalian renal medulla.

44 Fig The relationship between relative medullary area in the mammalian kidney (taken at the midline in sagittal section) and the maximal urine concentration that can be produced.

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49 Fig Nephrons from the major classes of vertebrates.

50 Fig Nephrons from the major classes of vertebrates.

51 Fig Avian urinary systems.

52 Fig Avian urinary systems.

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54 Fig Malpighian tubules. (a) The arrangement of these tubules in a typical insect. First, K + ions are transported into the proximal end of the tubule, drawing Cl - in by charge attraction and then water by osmosis.

55 Fig Malpighian tubules. (b) Countercurrent flow between the tubule and hindgut in some desert insects, with concentrations shown in mm. In these animals, the tubules bend posteriorly to lie against the rectum.