Copyright © 2008 Thomson Delmar Learning CHAPTER 16 Renal Failure and Its Effects on the Cardiopulmonary System.

Copyright © 2008 Thomson Delmar Learning

CHAPTER 16

Renal Failure and Its Effects on the Cardiopulmonary System

Copyright © 2008Thomson Delmar Learning

THE KIDNEYS


Urinary System Organs

Fig. 16-1. Organs of the urinary system. Urine is formed by the kidney and flows through the ureters to the bladder, where it is eliminated via the urethra.


Cross-Section of the Kidney

Fig. 16-2. Cross-section of the kidney.


THE NEPHRONS


The Nephron

Fig. 16-3. The nephron.


BLOOD VESSELS OF THE KIDNEYS


Blood Vessels of the Kidneys

Fig. 16-4. Blood vessels of the kidney.


Urine Formation

• Glomerular Filtration• Tubular Reabsorption• Tubular Secretion


Forces of Glomerular Filtration

Table 16-1


Urine Concentration and Volume

• Countercurrent mechanism• Selective permeability


Antidiuretic Hormone (ADH)

Fig. 16-5. Pathway by which antidiuretic hormone (ADH) is controlled. When the baroreceptors in the left atrium sense an increased pressure (increased plasma volume), they send neural impulses to the hypothalamus, causing the production of ADH to decrease. In contrast, a decreased pressure (decreased plasma volume) causes the production of ADH to increase.


Regulation of Electrolyte Concentration

• Kidneys play a major role in a normal cellular environment by regulating the concentration of various ions.

• Important ions regulated:– Sodium– Potassium– Calcium, Magnesium, and Phosphate


Role of Kidneys in Acid-Base Balance

• All the renal tubules are capable of secreting hydrogen ions

• Rate of secretion is directly proportional to hydrogen ion concentration in the blood



• Thus, when the extracellular fluids become too acidic, the kidneys excrete hydrogen ions into the urine



• In contrast, when the extracellular fluids become too alkaline, the kidneys excrete basic substances into the urine

– Primarily sodium bicarbonate



Fig. 16-6. The effect of extracellular fluid pH on urine pH.


Blood Volume

• Adult has normal blood volume of about 5 L

• It rarely increases or decreases more than a few hundred milliliters

• Two major mechanisms responsible for this constancy of the blood volume are the:

– Capillary fluid shift system– Renal system


Renal Failure (Common Causes of Renal Disorders)

• Congenital disorders• Infections• Obstructive disorders• Inflammation and immune responses• Neoplasm


Table 16-2

Factors that Obstruct Urinary Flow


Classification of Renal Disorders

• Prerenal conditions• Renal conditions• Postrenal conditions


Table 16-3

Prerenal Abnormalities


Renal Abnormalities

Table 16-4


Table 16-5

Renal Abnormalities


Mechanical Ventilation as a Cause of Renal Failure

• Positive pressure ventilation decreases urinary output

• Negative pressure ventilation increases urinary output


Cardiopulmonary Disorders Caused by Renal Failure

• Hypertension and edema• Metabolic acidosis• Electrolyte abnormalities

– Chloride abnormalities– Potassium abnormalities


Cardiopulmonary Disorders Caused by Renal Failure

• Anemia• Bleeding• Cardiovascular problems

Copyright © 2008 Thomson Delmar Learning CHAPTER 16 Renal Failure and Its Effects on the Cardiopulmonary System.

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