1. GU System (1)
A&P of the Kidneys

3. Functions of Urinary Systems
Urine formation
F & E control
Acid-base balance
Excretion of waste products
BP regulation
RBC
Regulation of Ca-Phos metabolism

4. Sequence of urine flow
Kidneys  Ureters  Urinary bladder  Urethra

5. Location of Kidneys
Retroperitoneal on either side of the vertebral column below the diaphragm

6. Kidney’s Gross Anatomy Structure
Hilus is a notch located near center of medial border. It’s where blood vessels, ureter, & nerves enter/exit the kidney
Renal Capsule outer covering of kidney that’s composed of strong connective tissue

7. Gross Anatomy (con’t)
Renal Cortex just beneath renal capsule & contains millions of renal tubules which are part of the microscopic filtration system
Medulla lies below renal cortex & contains pyramids which are triangular in shape

8. Gross Anatomy (con’t)
Papillae are the pointed ends of the pyramids whose main purpose is to empty urine into calyces
Calyces are cup like extensions of the renal pelvis which guide urine into the renal pelvis

9. Gross Anatomy (con’t)
Renal Pelvis is an expansion of the upper end of the ureter
Ureter drains urine into the bladder

10. Recap
Renal Capsule  Renal Cortex  Medulla  Pyramids  Papillae  Calyces  Renal Pelvis  Ureter  Bladder  Urethra

11. Microscopic Structure
Glomeruli = tightly bound network of capillaries which make  the Renal corpuscle
Glomeruli housed inside Bowman’s Capsule
R & L renal arteries branch abdominal aorta & enter hilus

12. Microscopic Structure (con’t)
R & L renal arteries branch off the Abd aorta & enter the the hilus  continuing branching off until blood is delivered to glomerulus by afferent arteriole
Blood leaves glomerulus via efferent arteriole to peritubular capillary

13. Microscopic Structure (con’t)
Blood reaches renal veins & flows into inferior vena cava

14. Microscopic Structure (con’t)
Renal tubule becomes tightly proximal convoluted tubule  Loop of Henle  distal convoluted tubule which the collecting tubule/duct
Juxtaglomerular apparatus plays a role in BP control
BP determines GFR (glomeruli filtration rate)

15. IV. Nephron Unit Functional unit of the kidney
Responsible for filtering blood & processing urine

16. Nephron Unit (con’t) 3 major functions
Controlling body fluid levels by selectively +/- H20
Assisting w/ pH regulation of blood
Removing toxic waste from the blood

17. V. Hormonal Influence on Nephron Function
BP  d/t:
 fluid loss b/c hemorrhage or blood loss in surgery
Diaphoresis
Vomiting
Diarrhea
NGT/GT secretion

18. Hormonal Influence (con’t)
Posterior pituitary releases ADH
ADH causes distal convoluted tubules to  rate of H20 reabsorption resulting in  in BP

19. VI. Nephron Role in UA Formation
See table 10-1, p. 411 (depending on version )
Glomerulus
Proximal convoluted tubule
Loop of Henle
Distal convoluted tubule & collecting tubules

20. VII. Process of UA formation
Glomerular filtration – filtration of H2O & blood occur in the glomerulus of Bowman’s capsule
Tubular Reabsorption of H2O, glucose, & necessary ion back into the blood occurs in proximal convoluted tubules, Loop of Henle & distal convoluted tubules which will re-absorb needed substances back into body

21. Process of UA formation (con’t)
Secretion of certain ions, nitrogenous wastes & drugs occurs mainly in distal convoluted tubule
Reverse of reabsorption
Substances move from blood to filtrate

22. VIII. Pressure Affecting Glomerular Filtration
Net filtration pressure
Hydrostatic pressure
Osmotic pressure  pressure that develops

23. IX. Hormones Affecting Kidney Function (p. 410-411, Herlihy)
Aldosterone (Aldactone)
Aldosterone is a hormone secreted by the adrenal cortex
 blood volume & also  BP
 aldosterone =
 BP =
 blood volume
Shock

24. Hormones Affecting Kidney Function (con’t)
Renin  an enzyme which initiates a series of events called the renin-angiotensin-aldosterone system
Secreted by the juxtaglomerular apparatus
Stimulated with either BP or blood volume 

25. X. Angiotensin II Production
Renin activates angiotensinogen to form Angiotensin I
Angiotensinogen is secreted by the liver & circulates in the blood in an inactive form
An enzyme called converting enzyme acts in the pulmonary capillaries to change Angiotension I  Angiotensin II

26. Angiotensin II Production (con’t)
Angiotensin II stimulates the adrenal cortex to release aldosterone which stimulates the distal tubule to reabsorb sodium & water
Excretion of potassium

27. RECAP Hormonal Influence
Renin activates Angiotensinogen (from the liver)  converting enzyme (from the lungs) converts Angiotensin I  Angiotensin II

28. XI. Urine Composition & Characteristics
Forms ~ 2 L/d
95% H2O
5% nitrogenous wastes & salts
Influenced by several factors What?
Slightly acidic w/ pH of 4.6  8.0
Healthy urine is sterile
Ammonia odor d/t break of urea

29. XII. Urine Abnormalities – Albumin
Albuminuria
Indicates possible
Kidney disease
 BP
Toxicity of kidney cells from heavy metals
Give examples of heavy metals, please.

30. Urine Abnormalities – Glucose
Glycosuria
Indicates
 Blood sugar (glucose) level
Blood glucose level rises above renal threshold
which kidney tubules can no longer reabsorb
Glucose spills into the urine

31. Urine Abnormalities – Erythrocytes
Hematuria
May indicate
Infection
Tumors
Kidney dz or calculi (stone)

32. Urine Abnormalities – Ketone Bodies
Ketonuria or ketoaciduria occurs when there is an excessive amount of fatty acid which are oxidized/ catabolized
Seen with DM
Starvation
Anorexia Nervosa

33. Urine Abnormalities – Leukocytes
Presence of WBCs (leukocytes) occurs in the presence of an infection or inflammatory process in the urinary tract