1. The Urinary System
Health Sciences 1

2. Performs the main part of the excretory function in the body
Most important organ of excretory system is the kidney
If kidneys fail, toxic wastes start to accumulate in the body which causes cells to “poison” the body.

3. Gross Anatomy
2 Kidneys 2 Ureters 1 Bladder 1 Urethra 1 Urinary meatus

4. Structures of the urinary system
Kidneys
Most important excretory organ
Bean-shaped
Located between peritoneum and the back muscles (retroperitoneal)
Held in position by connective tissue
Enclosed in an adipose capsule
Protected by the ribs

5. Structures of the urinary system
Kidneys
External structures
Renal capsule
Renal fascia
Renal hilum
Internal structures
Renal cortex
Renal medulla
Renal pelvis

6. Structures of the urinary system
External kidney
-- Renal Capsule
Kidney is enclosed within
Renal fascia
Fibrous layer of connective tissue that covers the kidney
Renal hilum
Indentation that gives the kidney its bean-shaped appearance (passageway for lymph vessels, nerves, renal artery and vein and ureter)

7. Structures of the urinary system
Internal kidney
Renal cortex
Outer layer
Renal medulla
Middle layer
Renal pelvis
Innermost layer

8. Structures of the urinary system
Renal cortex
Composed of millions of microscopic functional units called nephrons

9. Structures of the urinary system
Nephron
Functional unit of kidney
Renal corpuscle
Bowman’s capsule
Glomerulus
Renal tubule
Proximal convoluted tubule
Loop of Henle
Distal convoluted tubule
Collecting tubules
Each kidney contains about
1.3 MILLION nephrons!

10. Structures of the Urinary system
Renal medulla
Inner, striated layer
RENAL PYRAMIDS are the striated cones.
Base of each pyramid faces cortex, while apex empties into cuplike cavities called CALYCES
Renal columns
Located between the pyramids
Cortical tissue
4.01 Remember the structures of the urinary system

11. Structures of the urinary system
Renal pelvis
Funnel shaped structure at the beginning of the ureter
4.01 Remember the structures of the urinary system

12. Structures of the urinary system
Ureters
Muscular tube extending from each kidney to the urinary bladder
Lined by a mucous membrane
10-12” long
Ureters

13. Structures of the urinary system
Urinary bladder
Hollow muscular organ
Located in pelvic cavity
Made of elastic fibers and involuntary muscles

14. Structures of the urinary system
Female
Urethra
Connects the bladder to the outside of the body
Female 1-2” long
Male 4-6” long
Urinary meatus
Opening to the outside of the body
Male

15. What are the structures of the urinary system?

16. Understand the Functions and Disorders of the Urinary System

17. Understand the functions of the urinary system
Excretion
Process of removing nitrogenous waste materials, certain salts and excessive water from the blood

18. Understand the functions of the urinary system
Filtration
Reabsorption
Secretion

19. Filtration Blood from renal artery enters glomerulus
High pressure in glomerulus forces fluid into Bowman’s capsule, where it is filtered

20. Filtration BOWMAN’S CAPSULE
Bowman’s capsule filters out 125cc of fluid/min.
…how many cc’s per hour is this?
As the filtrate continues through nephron, 99% of water is reabsorbed— so only cc of urine are excreted daily.

21. Reabsorption
Substances include water, glucose, amino acids, vitamins, magnesium, sodium and potassium
Reabsorbed by the capillaries around the tubules.
If blood levels of certain substances are high, the substances will not be reabsorbed.
They remain in the tubules and are excreted in the urine.
Ex- glucose in diabetics “spilling” glucose in urine
Ex – medications – hence why medications need to be taken frequently

22. Secretion
This process is the opposite of reabsorption.

23. Secretion
Substances are secreted into the collecting tubules include ammonia creatinine, hydrogen ions, potassium and some drugs.

24. Understand the functions of the urinary system
Fluid and electrolyte balance
Electrolytes are selectively secreted to maintain body’s acid-base balance.

25. Control of urinary secretion
Fluid and electrolyte balance
Chemical control
ADH – Antidiuretic hormone
Aldosterone
4.02 Understand the functions and disorders of the urinary system

26. Understand the functions of the urinary system
Fluid and electrolyte balance
Chemical control
ADH is released by the posterior pituitary gland
* ADH increases size of cell membranes pores, allowing increased permeability to water.

27. Understand the functions of the urinary system
Fluid and electrolyte balance
Chemical control
The amount of ADH produced is related to the level of body hydration
Under control of the hypothalamus
4.02 Understand the functions and disorders of the urinary system

28. Understand the functions of the urinary system
Fluid and electrolyte balance
Chemical control
Aldosterone
Secreted by the adrenal cortex.
Promotes the excretion of potassium and hydrogen ions.
Aldosterone release is the result of the renin-angiotensin system.

29. Understand the functions of the urinary system
Fluid and electrolyte balance
Nervous control
Accomplished directly through action of nerve impulses within the kidney
Endrocine gland hormonal secretions will also control urinary secretion.

30. Understand the functions of the urinary system The flow of electrolytes
Review urine formation, electrolyte exchange, and some factors that effect urine volume.

31. Understand the functions of the urinary system
Elimination of urine
Bladder acts as a reservoir for urine.
Contains approximately 500 ml of urine.
Becomes distended and uncomfortable, letting us know it needs emptying.
Emptying bladder (voiding) takes place by muscular contractions of the bladder, which are involuntary, although they can be controlled in some extent through the nervous system.

33. Understand the functions of the urinary system
Elimination of urine
Urinary output
Average urinary output = 1500 ml per day
*How many ounces is this?
What effects the color of your urine?

34. Urinalysis An examination of urine What does normal urine look like?
Clear, straw clolored?
What constitutes an abnormal urinalysis?
Presence of blood, bacteria, etc.

35. Where would excess glucose show up?
Urinalysis
Where would excess glucose show up?
What does this mean?

36. 4.02 Understand the functions and disorders of the urinary system
Urinalysis
4.02 Understand the functions and disorders of the urinary system

37. Disorders of the urinary system

38. Disorders of the urinary system
Cystitis
What is cystitis
(cyst= medical term for ____ +itis =___ )
Most common cause: E. Coli
Symptoms
Painful (dysuria) or frequent (polyuria) urination

39. Disorders of the urinary system
Cystitis
More common in females—Why ??
Rx=
antibiotics

40. Disorders of the urinary system
Disease which injures the glomerulus.
What will happen as a result of damaged glomeruli?
Filtration process is
affected
Glomerulonephritis
4.02 Understand the functions and disorders of the urinary system

42. Acute Glomerulonephritis
Sudden onset
Occurs after bacterial infection (usually strep throat in children)
Treated with antibiotics

43. Chronic glomerulonephritis
Filtration membrane is permanently affected
Caused diminished function of the kidney
May result in kidney failure.

44. Renal Calculi Also known as kidney stones
Can be calcium, uric acid or other substances
They grow larger and eventually fill the renal pelvis and possibly obstruct flow of urine.
First symptom – extreme pain in kidney area or lower abdomen (colic)
Nausea and vomiting are common

45. May have painful urination, frequency, chills or fever
Possibility of blood in urine (hematuria)
Diagnosed with ultrasound or CT scan
Treat with increased fluids to flush stone out.
Possibility of lithotripsy (see page 437 medical highlight)
Meds for pain

46. Renal Failure Acute Sudden onset
Caused by inflammation of the nephron (nephritis), shock, injury, bleeding, heart failure or poisoning
Symptoms
Oliguria (scanty or diminished production of urine)
Anuria (absence of urine) – could be dangerous because of build up of toxins

47. Chronic renal failure Gradual loss of kidney functions.
Treat with Dialysis
Passage of blood through a device which rids the blood of harmful waste, extra salt, and water
These devices serve as a substitute kidney.
Two forms
Hemodialysis and peritoneal dialysis

48. Hemodialysis
Process for purifying blood by passing it through a thin membrane and exposing it to a solution which continually circulates around the membrane. Uses a machine called a dialyzer

49. Kidney Transplants
Done in cases of prolonged chronic debilitating diseases and renal failure involving both kidneys.
Usually clients have been on dialysis for a long time waiting for a compatible organ.
Daily meds to prevent rejection
Improve quality of life

50. Peritoneal dialysis
Uses the persons own peritoneal lining instead of a dialyzer to filter the blood.