Figure 18.1Urinary Sysstem URINARY SYSTEM

- Excretory System - composed of organs that excrete water and waste products in the form of urine

ORGANS: 1. Kidneys 2. Ureter 3. Urinary Bladder 4. Urethra

URINARY SYSTEM

FUNCTIONS: 1. Excretion of unwanted

substances i.e. waste products from cell metabolism, excess salts and toxins

2. Maintenance of water balance 3. Regulation of acid-base balance 4. Production of hormones i.e.

renin

Kidney - paired, reddish brown, retroperitoneal bean-shaped organ in superior lumbar region - extends from vertebral levels T12 superiorly and L3 inferiorly

Structures related to the anterior surface of each kidney.

Structures related to the posterior surface of each kidney.

Kidney

Coverings:

1. Renal capsule

2. perirenal fat (perinephric fat)

3. renal fascia (gerotas fascia)

4. Pararenal (paranephric fat)

2 parts:

1. cortex - outer

2. medulla

inner

- contains tubes that

collect urine

- these form a number of

cone shaped structures

called renal pyramids

- in between the pyramids

are the renal columns of

Bertini

- The tips of the

pyramids are

surrounded by cup

like structures

collecting urine

called minor calyces

- 2 or 3 minor calyces

would unite to form

the major calyces

- The major calyces

unite to form the

Renal Pelvis

Nephron - Structural and functional unit of the kidney

- 1 million nephron each kidney

Consists of the ff:

A. Renal(Malphigian) Corpuscle

1. glomerulus

2. Bowmans capsule

B. Tubules

1. Proximal convoluted tubule

2. Loop of Henle(descending/ascending)

3. Distal convoluted tubule

4. Collecting tubules

Figure 18.4

Ureter

- 10 inches long muscular tube

- 3 anatomical constrictions:

1. at the uretero-pelvic junction

2. where iliac vessels cross the ureter

3. where it joins the urinary bladder

Urinary bladder

Hollow muscular organ

Wall consist of detrussor muscle

Inner- trigone occupied by

ureteral orifices

and urethral orifice

Apex and Base 3 surfaces: 1 Superior and 2 infero-lateral

Surfaces and base are triangular in outline, slightly convex and separated by blunt borders

The base and infero-lateral surfaces meet at the neck and is continous with the urethra

Parts of Urinary Bladder

Male Urethra

1. Male 20 cm - both sperm and

urine passes

a. prostatic

- widest, most dilatable

b. membranous

- traverses urogenital

diaphragm, shortest

and least dilatable

c. penile

- longest, traverses

corpus spongiosum

Female Urethra

- tubes extending from

bladder to the outside

- Female urethra

- About 4 cm long

- Urethral opening is

located in front of

vaginal opening in the

vestibule

THE END

Thank you!

Henedina Eva Casis-Barilea MD;DTM&H; FPSA Associate Professor 1