The Urinary System
COMPONENTS:
• Kidneys (2)
• Ureters (2)
• Bladder
• Urethra
Kidneys are responsible for urine formation
General Functions
• Elimination of waste products
• Acid-base balance
• Controls the plasma volume in the body
• Controls the blood pressure
• Produce hormones
Controls the BP= enzyme is RENIN (activates the
RAAS)
Controls the BP
• ENZYME = RENIN
 Activates the ReninAngiotensin-AldosteroneSystem (RAAS)
Renin-Angiotensin-Aldosterone-System
Dehydration/ Excessive bleeding
↓
Decrease blood volume
↓
Decrease BP
↓
Activation of juxtaglomerular cell
(Production of renin)
 Active form of Vitamin D
 1,25-dihydroxycholecalciferol
 ERYTHROPOIETIN
 Stimulates new RBC in the bone
marrow
- Removal of kidney/kidney failue=
decrease erythropoietin= decrease
RBC= anemia= pt. Can't tolerate
exercise
Anatomy of the Kidneys
 Kidney
- bean-shaped
- location: retroperitoneal
- level: T12-L3
- R is lower than L
External Anatomy
 RENAL CAPSULE
 Barrier to trauma
 ADIPOSE TISSUE
 Composed of fats
 RENAL FASCIA
 Anchors the kidney on the
abdominal wall
Increase renin
↓
Renin: Angiotensinogen  Angiotensin I
↓
Increase Angiotensin I
↓
As blood flow occurs in the capillaries of the
lungs
(ACE: Angiotensin I  Angiotensin II)
Renin-Angiotensin-Aldosterone-System
Hormones
 CALCITRIOL
Internal Anatomy
 RENAL CORTEX
 Outer region