1. ST120 Concorde Career College, Portland
Urinary System
ST120
Concorde Career College, Portland

2. Objectives Define the term urinary
Describe the functions of the urinary system
List and identify the structures of the urinary system and describe the function of each

3. Objectives Describe the process of urine formation
Trace the flow of urine from the time it begins to form in the kidney until it exits the body
Describe the mechanism by which the urinary system helps to maintain homeostasis

4. Objectives
Describe common diseases, disorders, and conditions of the urinary system including signs and symptoms, diagnosis, and available treatment options
Demonstrate knowledge of medical terminology related to the urinary system verbally and in the written form

5. Urinary Defined
Pertaining to urine - the fluid and dissolved substances secreted by the kidneys.

6. Function of the Urinary System
Excrete water and waste products containing nitrogen and salts
Review - other body systems involved in excretion.
Digestive - eliminates water, some salts, bile, and undigested food in the feces. The liver is responsible for elimination of the products of red blood cell destruction and certain drugs and toxins.
Respiratory - eliminates carbon dioxide and water (vapor).
Integumentary - eliminates water, salts, and nitrogenous wastes in the perspiration.

7. Structures of the Urinary System
Kidneys (2)
Ureters (2)
Bladder (1)
Urethra (1)
Review basic urinary and regional anatomy found in diagram

8. Kidneys - Location Inferior to the diaphragm Protected by the ribs
Enclosed in a fibrous capsule and protected by a fat pad
Contained within the retroperitoneal space
Right is slightly lower than the left
The fibrous (peri)renal capsule is referred to as Gerota’s fascia/capsule and the fat pad is called the paranephric or perirenal fat pad.
Nearby muscles are the psoas (medial), transverse abdominal muscles (lateral), quadratus lumborum (posterior)
Right kidney is in contact with the right lobe of the liver superiorly and lateral to the hepatic flexure inferiorly. Pancreas lies across hilum of left kidney. Superior aspect is against stomach and spleen.

9. Kidneys - General Information
Renal artery delivers oxygenated blood to the kidney
Functional unit of the kidney is called the nephron
Deoxygenated blood leaves the kidney via the renal vein
The kidney is considered a parenchymal (consisting primarily of functional tissue) organ.
Each kidney contains approximately one million nephrons.
Be sure to point out the hilus - the point where the artery, vein, and ureter enter/exit the organ.
Note the “bean-shaped” appearance (refer to kidney beans/kidney basin).

11. GU System Dissection Video
Cadaveric Retroperitoneal Space
Go to video by clicking the link above the picture. You will need a login ID for YouTube in order to view the video.

12. Kidney Structure Three Regions: 1. Cortex 2. Medulla 3. Renal Pelvis
1. Cortex - outer portion of the kidney.
2. Medulla - middle portion of the kidney that contains the pyramids. The tips of each pyramid point toward the renal pelvis.
3. Renal Pelvis - Funnel shaped basin that forms the upper end of the ureter. Extensions of the renal pelvis called calyces surround the tips of the pyramids and collect urine and direct it into the renal pelvis.
The definition of pelvis is any basin-like or cup shaped cavity.

13. A More Detailed View Renal capsule Cortex Medulla Calyces Renal Pelvis
Pyramids
Calyces
Minor
Major
Renal Pelvis
Ureter
The dashed blue line indicates the division between the renal cortex and the medulla.
Be sure to point out the minor and major calyces and the extension of the renal pelvis that forms the proximal ureter.
Portions of each nephron are in the cortex and the medulla (refer to next slide).

14. Surgical specimen. Note the hilum.

15. Microscopic Section of the Kidney
Note position of nephron in cortex and medulla
If all of the nephrons were separated, straightened and laid end-to-end they would cover approximately 120 kilometers or 75 miles!!!

16. Nephron Two Divisions: 1. Vascular 2. Tubular
The vascular and the tubular divisions work together to produce urine.
Functions of the Kidneys:
1. Excretion of unwanted substances such as waste products from cell metabolism excess salts, and toxins. The main waste product of amino acid metabolism is a nitrogenous waste chiefly in for form of urea.
2. Maintenance of water balance. The amount of fluid taken in is approximately equal to the amount of fluid lost. Intake = output.
3. Regulation of acid-base balance.
4. Production of renin, an enzyme that is important in blood pressure regulation. If B/P falls too low for effective glomerular filtration, the cells of the juxtaglomerular (JG) apparatus release renin which in turn activates a protein called angiotensin that causes vasoconstriction and raises the blood pressure.
Production of the hormone erythropoietin which stimulates production of RBCs in the red bone marrow. The hormone is produced when the kidneys are not getting enough oxygen.
The glomerulus and Bowman’s capsule make up the renal corpuscle.

17. Nephron Vascular Division: Afferent arteriole Glomerulus
Efferent arteriole
Peritubular capillaries
Venule
Afferent arteriole - Receives blood from the renal artery via the abdominal aorta and supplies the Bowman’s capsule with blood.
Glomerulus - Specialized cluster of capillaries that is surrounded by the Bowman’s capsule.
Efferent arteriole - Carries blood to the peritubular capillaries.
Peritubular capillaries - Surround the tubules.
Venule - Returns blood from the peritubular capillaries to the renal vein which empties into the inferior vena cava.

18. Microscopic View of the Glomerulus

19. Nephron Tubular Division: Bowman’s Capsule Proximal Convoluted Tubule
Loop of Henle
Distal Convoluted Tubule
Juxtaglomerular Apparatus
Collecting Tubule/Duct
Minor Calyx
Major Calyx
Renal Pelvis
Ureter
Bowman’s Capsule - Surrounds the glomerulus; collects fluid from the glomerulus.
Proximal Convoluted Tubule -Coiled portion of the tubule leading from the Bowman’s capsule.
Loop of Henle - Hairpin shaped segment of the tubule.
Distal Convoluted Tubule - Coiled portion of the tubule that follows the loop on Henle. The DCT eventually empties collecting tubule.
Juxtaglomerular Apparatus - Point at which the distal convoluted tubule contacts the afferent arteriole. Releases enzyme renin if BP is too low. Renin activates the protein angiotensin to cause vasoconstriction thereby raising the blood pressure.
Collecting Tubule/Duct - Directs urine toward the calices.
Minor Calyx - Collects urine from the collecting tubules.
Major Calyx - Collects urine from the minor calices.
Renal Pelvis - Collects urine from the major calices.
Ureter - Directs urine from the major calices toward the bladder.

20. Physiology Glomerular filtration Tubular reabsorption
Tubular secretion
Concentration of urine
Glomerular filtration - Allows materials to pass from the blood into the nephron. All large proteins and blood cells are retained in the blood.
Tubular reabsorption - Moves useful substances back into the blood while keeping waste products in the nephron to be eliminated.
Tubular secretion - Additional substances are moved from the blood into the nephron for elimination. Movement of hydrogen ions helps maintain pH.
Concentration of urine - Pituitary hormone ADH allows water to be reabsorbed from the nephron concentrating the urine and reducing the volume excreted.

21. Urochrome is the pigment that gives
Reabsorption: Begins in the proximal convoluted tubules and continues in the loop on Henle, distal convoluted tubules and collecting tubules
Large amounts of water—approximately 178 L per day are absorbed by osmosis
Urochrome is the pigment that gives
urine its normal yellow-amber color
-- Color can be influenced by normal
factors such as the amount of liquid
consumed or by disease or medications
99% of filtrate is reabsorbed in the peritubular capillaries and is not excreted.

22. Kidney – Blood Supply Renal artery Segmental arteries
Interlobular arteries
Arcuate arteries
Intertubular arteries
Afferent arterioles
Renal artery enters kidney at the hilum then divides into segmental, then interlobular arteries that pass between the renal pyramids and across the renal columns. Arcuate arteries are brnached of the interlobular arteries that arise at the junction of the medulla and cortex. These arteries become the intertubular arteries and then become the afferent arterioles that enter the nephrons.

23. Kidney-Blood Supply Arterial flow through the kidney: Aorta
Renal artery
Segmental artery
Interlobular artery
Arcuate artery
Afferent arteriole
Glomerular capillary
Efferent arteriole
Peritubular capillary
Interlobular vein
Arcuate vein
Renal vein
Inferior vena cava
Right atrium
This is the correct order. Make sure to review in depth! Students must know how to trace the pathway throughout this system.

24. Ureters
Muscular tubes that convey urine from the kidney to the bladder by gravity and peristalsis
Approximately inches in length

25. Ureters
Ureter seen during endoscopic hysterectomy. Note how similar it is to surrounding structures such as the uterine artery, or pelvic ligaments. How can you correctly identify the ureter? Grasp with DeBakey forceps to stimulate peristalsis which can be seen coursing throughout the ureter.

26. Bladder Temporary reservoir for urine Layers Trigone Mucous membrane
Rugae
Submucosa
Connective tissue
Muscularis
Three layers
Serosa/Adventitia
Trigone

27. Urination (Micturition)
Internal sphincter
Involuntary
External sphincter
Voluntary (with age)
Urethra
Extends from the bladder to the outside
Meatus

29. Urethra The tube extending from the bladder to the outside of the body
Two urinary sphincters
- One controls the flow of urine
from the bladder into the urethra
- One controls the flow of urine
from the urethra through the
urethral meatus
Female urethra is approximately 1.5 inches long
Male urethra is approximately 8 inches long

30. Urethral Meatus
The urethral meatus is the external opening of the urethra
Female urethra is approximately 1.5 inches long
Male urethra is approximately 8 inches long
Is the meatus in the picture in the normal anatomic location? If not, what condition does this patient have?

31. Control of Urine Volume
Mainly controlled by the amount of water and dissolved substances that are reabsorbed
ANH: increases urine formation
Secreted by the atria of the heart when BP increases
Aldosterone: decreases urine formation
Secreted by the adrenal glands in response to increased K level, decreased sodium levels, decreased blood pressure
ADH: decreases urine
Secreted by the posterior pituitary gland when water level in the body is too low
Aldosterone: stimulated the reabsorption of sodium ions
where sodium goes water follows
Atrial natriuretic hormone: antagonist to aldosterone….expansion of atrial walls in response to ^BP or ^BV stimulates its release
decreases reabsorption of sodium ions
Antidiuretic Hormone: causes the distal convoluted tubules and collecting ducts to increase their reabsorption of water

32. Micturition AKA urination, voiding Passage of urine from the body
As the bladder wall stretches, nerve impulses are sent to the spinal cord and an emptying reflex is initiated
The reflex causes contraction of the bladder wall and relaxation of the internal sphincter and urine enters the urethra

33. Terms Retention Suppression Incontinence Involuntarily Cystitis
Retention: no urine is voided
Suppression: no urine is produced
Incontinence: patient voids urine involuntarily
Cystitis: bladder infection
Note the presence of inflammation in the picture. This is what bladder cystitis looks like.

34. Terms Glycosuria Anuria Oliguria Polyuria
Glyucosuria – A condition characterized by an excess of sugar in the urine, typically associated with diabetes or kidney disease
Anuria- absence of urine
Oliguria- scanty amounts of urine
Polyuria- an unusually large amount of urine; need for frequent urination due to excessive production
Anuria and oliguria can be directly related to benign prostatic hypertrophy (BPH)

35. Kidney Stones Calculi are typically composed of calcium (75%)
Etiology unknown, but likely triggered by diet
Lower calcium diet may decrease stone formation
Recur in 50% of patients
May become lodged and cause obstruction
Hydronephritis
Stones 3mm or smaller typically pass on their own but very painful – prescribed analgesics and inflammatories.
Stones 4mm or greater usually treated surgically: ESWL, percutaneous lithotomy, transurethral extraction/removal, or surgical removal – pg. 358

36. Kidney Stones
Note the staghorn calculus. It gets its shape from being wedged within the renal pelvis or calyces.

37. Nephrectomy Nephrectomy = surgical removal of the kidney
This is a hand-assisted dissection.
Why would a patient need to undergo this procedure?

38. Cystoscopy
Visualization of bladder
Urethroscopy
Ureteroscopy