1. Urinary System

2. Functions of the Urinary System
Primary: Elimination of waste products:
Nitrogenous waste
Toxins
Drugs
Secondary: Regulate homeostasis
Water balance
Electrolytes
Acid-base balance
Blood pressure
RBC formation

3. Organs of Urinary System
Kidneys
Ureters
Urinary Bladder
Urethra

4. Location of Kidneys

5. Kidney Regions Renal cortex—outer region
Renal medulla—inside the cortex
Renal pelvis—inner collecting tube

6. Kidney Structures
Renal or medullary pyramids—triangular regions of tissue in the medulla
Renal columns—extensions of cortex-like material inward that separate the pyramids
Calyces—cup-shaped structures that funnel urine towards the renal pelvis

7. Kidney Functions
One-quarter of the total blood supply of the body passes through the kidneys each minute
Renal artery provides each kidney with arterial blood supply
Renal artery divides into segmental arteries  interlobar arteries  arcuate arteries  cortical radiate arteries

8. Nephrons The structural and functional units of the kidneys
Responsible for forming urine
Main structures of the nephrons
Glomerulus
Renal tubule

9. Nephrons Glomerulus Knot of capillaries
Capillaries are covered with podocytes from the renal tubule
Glomerulus sits within a glomerular (Bowman’s) capsule (the first part of the renal tubule)

10. Nephron
Renal tubule extends from glomerular capsule and ends at the collecting duct
Glomerular (Bowman’s) capsule
Proximal convoluted tubule (PCT)
Loop of Henle
Distal convoluted tubule (DCT)

15. Angiotensin II formed in blood Peripheral resistance
Falling systemic blood pressure volume
Reduced filtrate volume or solute content in renal tubules
JG cells of kidneys
(+)
(+) = stimulates
Renin-angiotension system
Neural regulation (sympathetic nervous system effects)
Effects of ADH release
Renin
Release
Leads to
Angiotensin II formed in blood
Systemic arterioles
Vasoconstriction
Peripheral resistance
Adrenal cortex
Aldosterone
Kidney tubules
Na+ reabsorption (and H2O absorption)
Blood volume
Rising blood pressure
Causes
Results in
Secretes
Targets
Releases
Inhibits baroreceptors in blood vessels
Sympathetic nervous system
Hypothalamic osmoreceptors
Posterior pituitary
ADH (antidiuretic hormone)
Collecting ducts of kidneys
H2O reabsorption
KEY:

16. Urinary System Video

17. Kidney Transplant Video