1. 15
The Urinary System

2. I. Introduction: A. Parts1) 2) 3) 4)
B. Overall Functions: The blood is modified to produce:
Elimination of:
Nitrogenous wastes
Toxins
Drugs
Kidney
Ureter
Bladder
Urethra

3. Functions of the Urinary System …
2. Regulate Blood Levels of:
Water, which affects Blood Pressure
Electrolytes/ions
H+: To maintain blood pH

4. II. Kidney Anatomy Location: Retroperitoneal = B. Gross Anatomy
At T12 to L3 vertebrae
B. Gross Anatomy
Adrenal Glands
Renal Hilum
Cortex
Medulla
12th rib

5. C. Microscopic Anatomy: The Nephron
Bowman’s Capsule
1. Glomerulus:
2. Renal Tubule:
a. Bowman’s Capsule
Glomerulus
Cortical
nephron
Fibrous capsule
Renal cortex
Collecting
duct
Renal medulla
Renal
cortex
Proximal
convoluted
tubule
Renal pelvis
Glomerulus
Ureter
Distal
convoluted
tubule
Loop
of Henle
Renal
medulla
(a)

6. 3. Nephron …
b. Proximal Convoluted Tubule c. Nephron Loop or Loop of Henle d. Distal Convoluted Tubule
Cortical
nephron
Fibrous capsule
Collecting
duct
Renal
cortex
Proximal
convoluted
tubule
Glomerulus
Ureter
Distal
convoluted
tubule
Loop
of Henle
Renal
medulla
(a)

7. D. Other Microscopic Parts
Collecting Duct
2. Afferent Arteriole  Glomerulus
Renal Artery
Cortical
nephron
Fibrous capsule
Collecting Duct
Collecting
duct
Renal
cortex
Afferent Arteriole
Proximal
convoluted
tubule
Glomerulus
Ureter
Distal
convoluted
tubule
Loop
of Henle
Renal
medulla

8. III. KIDNEY FUNCTIONING:
A. Glomerular Filtration
- Occurs at Glomerulus and Bowman’s Capsule
Review Filtration
1. WHY: to get the plasma with dissolved chemicals into the Kidney tubes for processing
2. Small substances are filtered into Kidney
Water and solutes– are forced through holes in capillary walls
And Nitrogenous : Urea
3. Large substances stay in the blood:
Proteins and blood cells

9. B. Tubular Reabsorption =
Locations: Proximal Convoluted Tubule and Nephron Loop, Collecting duct mostly
2. WHY: to get the nutrients and important chemicals needed by the body back into the blood
3. Materials that are reabsorbed:
Water
Glucose
Amino acids
Ions: amount reabsorbed depends on how high the level are in the blood
4. Wastes usually not reabsorbed:
Nitrogenous waste products– Urea, Uric acid, Creatinine

10. C. Tubular Secretion =
Location: Distal Convoluted Tubule and Loop mostly
2. Substances secreted: Hydrogen and potassium ions
3. WHY: if there are too high of levels in the blood, filtration does not move enough of these chemicals into the kidney tubes. Then more can be put their by secretion.

11. D. Water Balance Must be Maintained in Body
WHY: to keep the proper concentrations of chemicals in blood and cells AND maintain proper Blood Pressure
2. Most water is reabsorbed: occurs automatically throughout the tubes so that the body will not dehydrate
3. Control of amount of water in urine: Only at the end of the Nephron Tubes is the water content of urin controlled
Locations: Nephron Loop & Collecting Duct are most important
Control System: Endocrine System
Hormone: = Antidiuretic hormone (ADH)
High levels cause more water to be reabsorbed to prevent dehydration
Low levels cause more water to stay in urine

12. Hepatic veins (cut) Inferior vena cava Renal artery Adrenal gland
Renal hilum
Aorta
Renal vein
Kidney
Iliac crest
Ureter
Rectum (cut)
Uterus (part
of female
reproductive
system)
Urinary
bladder
Urethra
(a)
Figure 15.1a

13. IV. Characteristics of Urine
A. *Normal amount produced in 24 hr =
B. *Color range:
*How is urine color affected by concentration
How is the amount of water one drinks affect the concentration and color of urine:
C. *pH =
D. Specific Gravity = Weight as compared to pure water:

14. Characteristics of Urine …
E. Solutes in Urine:
1. Ions: Sodium and potassium ions and other ions
2. Nitrogen-containing substances: Urea, uric acid, creatinine, Ammonia
F. *Substances Not in Urine: Bile, and RBC, WBC, Platelets, Protein, Nutrients
G. Kidney Disorders: What abnormal substances in the urine indicates
Kidney Failure: Proteins in urine
Hemodialysis: Blood passes into machine which functions as the kidney; takes hours per day

15. Abnormal Urine Constituents
KNOW
Substance
Name of Condition
Possible Causes
Glucose
Glucosuria
Excess sugary intake; diabetes mellitus
Proteins
Proteinuria
Physical exertion, pregnancy; glomerulonephritis, hypertension
Pus (WBCs and bacteria)
Pyuria
Urinary tract infection
RBCs
Hematuria
Bleeding in the urinary tract
Hemoglobin
Hemoglobinuria
Various: transfusion reaction, hemolytic anemia
Bile pigments
Bilirubinuria
Liver disease (hepatitis)
Indicates Kideny Damage

16. V. Ureters VI. Urinary bladder * = describe *Function
= Smooth, collapsible, muscular sac that connects to the Ureters superiorly and the Urethra inferiorly
*Function:
Ureters
Uterus
Bladder
Urethra

17. VII. Urethra = describe *Function: Location
Females—anterior to the vaginal opening
Males—travels through the prostate and penis

18. VIII. The Link Between Water and Salt
Water easily diffuses between the 3 Compartments
Most important solutes are electrolytes = Ions
Changes in solute concentration of a compartment changes the concentration of water and creates a High  Low
When solutes move from one compartment to another, the water will diffuse and follow the solute. Consequences:
Alters blood volume and blood pressure
Can impair the activity of cells
So, Water Intake Must = Water Output
and the Concentrations of ions must be kept at Homeostasis by the Kidneys

19. Water Intake– controlled by Hypothalamus via making one thirsty
Water Intake– controlled by Hypothalamus via making one thirsty. Stimuli that trigger Thirst are:
Increase in plasma solute content
*Mouth is:
*Blood volume or blood pressure that:
Water loss– via
*Skin: called what?
Evaporation from Lungs
*End Product of Digestive System: ?
KIDNEYS: then compensate for the above water losses by altering the amount of water in the urine :

20. IX. Acid-Base Balance
END