A&P of the Urinary System

Transcription

1 A&P of the Urinary System Week 44 1

2 Objectives Identify the organs of the urinary system, from a Identify the parts of the nephron (the functional unit List the characteristics of a normal urine specimen. Give a list of abnormal findings, briefly explain the State normal and minimal urine outputs. 2

3 Objectives Define key words. Describe various procedures used in diagnosis of disease and disorders of the urinary system, giving the nursing responsibilities for each. Differentiate between normal and abnormal laboratory findings. 3

4 Kidneys Two kidneys Retroperitoneal Adipose cushion 4

5 Functions of the kidney Maintenance of ph Regulation of water and electrolyte elimination Elimination of waste products and toxic substances Stimulation of red blood cell production (erythropoieten) Contributes to control of blood pressure 5

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7 Internal Structure 7

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9 Nephrons Functioning part of the kidney 2 types: cortical (superficial) & juxtamedullary In both types the distal tubule empties into the collecting tubules Consists of glomerulus, water and solutes are filtered from the blood Tubules, reabsorb essential minerals from the filtrate and permit waste substances to be eliminated 9

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11 The Nephron Functional unit of the kidney 1 million nephrons per kidney 11

12 Urine is produced by Glomerular filtration Tubular reabsorption Tubular secretion 12

13 Glomerular filtration Filtration = The forcing of fluids and dissolved substances through a membrane by pressure Occurs in the glomerolus Composition of filtrate similar to plasma containing glucose, amino acids, salts urea and uric acid Blood and proteins only when damaged Approximately 600mls blood pass through glomerolus/minute only 120mls becomes filtrate GFR= amount of filtrate formed/minute (about ml) 13

14 Tubular re-absorption 99% of filtrate is re-absorbed allowing body to retain essential nutrients and fluid All glucose should be reabsorbed Majority of sodium and potassium are actively reabsorbed from proximal convoluted tubule Na reabsorption depends on blood pressure ADH makes distal convoluted tubule more permeable therefore more water reabsorbed 14

15 Mechanisms of Reabsorption Active transport Passive transport Osmosis Pinocytosis 15

16 Tubular secretion From blood into filtrate Includes k, H, creatinine and certain drugs If Na is reabsorbed K is secreted (controlled by aldosterone) HCO3 is increase or decreased to regulate ph 16

17 Hormones Aldosterone Atrial natriuretic peptide (ANP) Antidiuretic hormone (ADH) 17

18 Pre-requisite for normal urine production Adequate Blood Supply Pre Renal Normal Kidney Renal No obstruction to urine flow Post Renal 18

19 Definitions Normal urine output > 1ml/Kg/Hr 1 2L/day Oliguria 400 ml/ Day Anuria <100 ml/day Absolute Anuria nil 19

20 Characteristics of Urine Amount: 1-2 liters/24 hours Color: straw or amber, clear Specific gravity: ph: % water Nitrogenous wastes: Urea, creatinine, uric acid, Urobilinogen 20

21 Abnormal Constituents Glucose Protein Blood Bacteria Ketones 21

22 Do not permit urine volume to fall below 0.5mls/Kg/min for more than 2 hours without investigation or treatment If you do Acute tubular necrosis may develop and this is very BAD 22

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24 Other Functions Renin secretion maintain Cardiac output and BP Secretion of erthropoeitin Activation of vitamin D 24

25 Elimination Kidney Ureter Bladder Urethra 25

26 Urination Reflex Urination= micturationvoiding Reflex that can be voluntarily controlled Bladder volume: approx 800mL max Stimulation occurs with mL 26

27 Aging and the Urinary System Number of nephrons decreases Lose ability to concentrate urine Bladder decreases in size Decreased detrusor muscle tone Creatinine clearance decreases Greater incidence of nocturia Incontinence is not normal at any age 27

28 Assessment Skin color, presence of crystals, turgor Respiratory rate and rhythm Edema Tenderness Urine characteristic Palpate bladder 28

29 Labwork Urinalysis Urine culture and sensitivity Creatinine clearance BUN Serum creatinine Serum electrolytes 29

30 Radiographic Studies KUB IVP Arteriogram Cystogram Renal Scan CT MRI Ultrasonography Renal Biopsy Cystoscopy 30

31 Cystogram 31

32 Common Therapeutic Procedures Urethral Catheterization Ureteral Catheterization Nephrostomy tube Urinary stent Nephrectomy Lithotripsy Cystectomy 32