1. The Urinary System

2. Function Remove nitrogenous wastes
Maintain electrolyte, acid-base, and fluid balance of blood
Homeostatic organ
Acts as blood filter
Release hormones: calcitriol & erythropoietin

3. Kidneys as Filters Diuretic- loose water; coffee, alcohol
Antidiuretic- retain water; ADH
Aldosterone- sodium & water reabsorption, and K+ excretion
GFR= 180 liters (50 gal) of blood/day
liters are reabsorbed back into blood
Excrete a protein free filtrate

4. Organs of the Urinary System
kidneys
ureters
urinary bladder
urethra

5. A Kidney Blood and waste enter through renal artery
Filtered blood leaves through renal vein
Excess water and toxic waste leaves through ureter as urine

6. The Urinary System

7. General Functioning of the Kidney

8. Nitrogenous Wastes Proteins Amino acids COOH -NH2 Ammonia Urea
Uric Acid

9. Kidney Anatomy ureter nephron renal cortex renal medulla renal pelvis
renal pyramids
ureter
renal capsule

10. renal cortex renal medulla
Each kidney contains over 1 million nephrons and thousands of collecting ducts
Glomerulus
DCT
renal cortex
renal medulla
PCT
Collecting duct
Loop of Henle

11. DCT
PCT
Glomerulus
Collecting duct
Peritubular capillaries
Loop of Henle
To renal pelvis

12. Glomerular Filtration
afferent arteriole
glomerulus
Bowman’s capsule
efferent arteriole
Filters blood; proteins can’t pass through

13. Composition of Glomerular Filtrate
Water
Small Soluble Organic Molecules
Mineral Ions

14. Proximal Convoluted Tubule
Reabsorbs: water, glucose, amino acids, and sodium.
65% of Na+ is reabsorbed
65% of H2O is reabsorbed
90% of filtered bicarbonate (HCO3-)
50% of Cl- and K+

15. Loop of Henle
Creates a gradient of increasing sodium ion concentration towards the end of the loop within the interstitial fluid of the renal pyramid.
25% Na+ is reabsorbed in the loop
15% water is reabsorbed in the loop
40% K is reabsorbed in the loop

16. Distal Convoluted Tubule
Under the influence of the hormone aldosterone, reabsorbs sodium and secretes potassium. Also regulates pH by secreting hydrogen ion when pH of the plasma is low.
only 10% of the filtered NaCl and 20% of water remains

17. Collecting Duct Allows for the osmotic reabsorption of water.
ADH (antidiuretic hormone)- makes collecting ducts more permeable to water-- produce concentrated urine

18. Urine Water- 95% Nitrogenous waste: urea uric acid creatinine Ions:
sodium
potassium
sulfate
phosphate
From the original 1800 g NaCl, only 10 g appears in the urine

19. Urinary Bladder ureters urethra internal sphincters
external sphincters

20. Diuresis (Micturition)
When bladder fills with 200 ml of urine, stretch receptors transmit impulses to the CNS and produce a reflex contraction of the bladder (PNS)
When is incontinence normal?

21. Urinalysis Why do doctors ask for a urine sample? characteristics:
smell- ammonia-like
pH , ave 6.0
specific gravity– more than 1.0; ~
color- affected by what we eat: salty foods, vitamins

22. Odor odor- normal is ammonia-like
diabetes mellitus- smells fruity or acetone like due to elevated ketone levels
diabetes insupidus- yucky
asparagus---

23. Color Color- pigment is urochrome
Yellow color due to metabolic breakdown of hemoglobin (by bile or bile pigments)
Beets or rhubarb- might give a urine pink or smoky color
Vitamins- vitamin C- bright yellow
Infection- cloudy

24. Specific Gravity Water: s.g. = 1g/liter; Urine: s.g. ~ 1.001 to 1.030
When urine has high s.g.; form kidney stones
Diabetes insipidus- urine has low s.g.; drinks excessive water; injury or tumor in pituitary

25. pH- range ave 6.0
vegetarian diet- urine is alkaline
protein rich and wheat diet- urine is acidic

26. Normal Constitutes of Urine

27. Normal Constitutes of Urine

28. Abnormal Constitutes of Urine
 Glucose
Indicative of:
Excessive carbohydrate intake
Stress
Diabetes mellitus

29. Abnormal Constitutes of Urine
Albumin

30. Abnormal Constitutes of Urine
Ketone
RBC
Hemoglobin
Bile
WBC
Casts

31. INQUIRY List several functions of the kidneys.
What does the glomerulus do?
What are several constitutes you should not find in urine?
What is specific gravity?
What two hormones effect fluid volume and sodium concentration in the urine?
Where are the pyramids located in the kidney?
What vessel directs blood into the glomerulus?
Where does most selective reabsorption occur in the nephron?

32. Moment of Zen