1. Exercise 26 Functional Anatomy of The Urinary System

2. Gross Anatomy of the Human Urinary System
Renal capsule
a tough fibrous layer surrounding the kidney and covered in a thick layer of adipose tissue. It provides some protection from trauma and damage.

3. Organs of the Urinary System
Kidneys
Ureters
Urinary bladder
Urethra
Renal Artery
Figure 15.1a

4. Urinary System Organs
Function
Kidneys
Maintains water and electrolyte balance of the blood
Produces urine
Ureters
Transports urine to urinary bladder
Urinary bladder
Serves as a storage area for urine
Urethra
Transports urine to the body’s exterior
Is shorter in women than in men
Renal Artery
Transports arterial blood to the kidney

5. Internal Anatomy of the Kidney
Renal cortex —outer region; contains most of nephron structure
Renal medulla —inside the cortex; contains inner collecting ducts
Renal pelvis – basin continuous with ureter
Renal columns —extensions of cortex-like material inward that separate the pyramids
Calyces —cup-shaped structures, extensions of pelvis that funnel urine
Renal or fibrous capsule -- a tough fibrous layer surrounding the kidney

6. Internal Anatomy of the Kidney

7. Functional Microscopic Anatomy of the Kidneyb a c
Interlobular vein h e d
Interlobular artery g f i j

8. n c g a e h b f d k

9. Glomerulus= site of filtrate formation
Red arrows = Blood
Blue arrows = Filtrate
Glomerulus = a tiny ball-shaped structure composed of capillary blood vessels actively involved in the filtration of the blood to form urine .
Bowman’s Capsule =Fluids from blood in the glomerulus are collected in the Bowman's capsule (i.e., glomerular filtrate) and further processed along the nephron to form urine.

10. Proximal convoluted tubule= primary site of tubular reabsorption
Glucose, Amino Acids, Na+, and Water are being reabsorbed by the Proximal Convoluted Tubule

11. Collecting Ducts- collects the urine from the nephron and send it to the ureter.

12. Peritubular capillaries – receives substances from the tubular cells

13. Bowman’s Capsule: the inner membrane forms part of the filtration mechanism
There are two layers of cells that fluid (with its contents) has to pass through during filtration.
The second layer is the visceral layer of the Bowman’s capsule, formed by podocytes
The first layer is the endothelium of the
glomerular capillary.

14. The renal corpuscle is where plasma is filtered from capillaries into the renal tubules. At the center of renal corpuscle is the glomerulus, a meshwork of capillaries. The glomerulus is surrounded by Bowman's capsule

15. Glomerulus and Bowman’s Capsule
Visceral layer
Parietal layer
Podocytes make up the visceral layer of Bowman’s Capsule

16. Glomerulus is a high-pressure capillary bed
The afferent arteriole feeding the glomerulus is larger than the efferent arteriole which drains the glomerulus
The high pressure forces out fluid and blood components smaller than proteins from the glomerulus into the glomerular capsule

17. Proximal Convoluted Tubule
The cuboidal cells of the proximal convoluted tubule have long microvilli (brush border) on their inside surface that dramatically increase the surface area for reabsorption from the filtrate.
Filtrate
What is the purpose of this brush border epithelium?
Close up of brush border (microvilli)

18. n c g a e h b f d k

19. Glomerular capsule
Proximal convoluted tubule
Loop of Henle
Distal convoluted tubule
Collecting duct
Nephron in Cortex
Renal Cortex = nephron
Medullary pyramid = collecting ducts
Calyces
Renal pelvis
Ureter
(Ureter)
Bladder
Urethra

20. Urinalysis: Characteristics of Urine
In 24 hours, about 1.0 to 1.8 liters of urine are produced
Nitrogenous wastes normally found in urine:
Urea, uric acid, creatine
URIC ACID
UREA
CREATINE

21. Gout
Uric acid is derived from the breakdown of DNA and RNA. This is taking place continuously in the body as large numbers of cells are produced and replaced, particularly from the blood.
Purines are one type of nitrogenous base found in nucleic acids. In DNA and RNA, which are both nucleic acids, the major purines are guanine and adenine. Purines are found in many foods, including meat, shellfish, and sweetbreads
Birds excrete most of their nitrogen in the form of uric acid, an oxidized purine.

22. Substances absent from filtrate and urine
Blood proteins
Red blood cells
Hemoglobin
White blood cells (pus)
RBCs
White blood cells (pus)
Hemoglobin
Albumin

23. Substances present in filtrate but not in urine product
Urine is what remains after the filtrate has lost most of its water, nutrients, and necessary ions

24. Kidney
This is a low power view of a cross section through the kidney. Note the inner medullary tissue (green) surrounded by the outer cortical tissue (blue)

25. Cortex
Identify a glomerulus, which appears as a ball of tightly packed material containing many small nuclei
Notice the vacant appearing region corresponding to the glomerular capsule that surrounds it.
The balance of the kidney tissue consists of renal tubules.

26. Loop of Henle
(D) Descending limbs of the loop of Henle look similar to the proximal tubule, with apical brush borders. (Blue) (A) Ascending limbs are composed of cuboidal cells, but unlike the proximal convoluted tubule, they do not have apical brush borders. (Green) (C) Collecting ducts can also be seen on this slide. They can be easily distinguished by the presence of prominent lateral borders between adjacent cells. (Orange)

27. Loop of Henle
Descending limb, with its brush border similar to that of the proximal tubule. (Blue)
Ascending limb lacks this brush border and its cells have a more squamous appearance. (Red)
Collecting duct can be observed. (Purple)

28. Renal Pelvis
Urine in the collecting ducts eventually empties into the renal pelvis. Renal pelvis is the initial dilated portion of ureter.

29. Ureter

30. Urinary Bladder
The urinary bladder is lined by transitional epithelium, underneath which are thick layers of smooth muscle interwoven in various directions.
Compare the transitional epithelium between a relaxed bladder and a distended bladder.

31. Urethra