1. THE URINARY SYSTEM The kidneys filter blood
Plasma and they return most of the water and solutes to the bloodstream.
The remaining water and solutes constitute urine, which passes
through the ureters and is stored in the urinary bladder until it is
excreted from the body through the urethra
CONSISTS OF :
1-TWO KIDNEYS
2-TWO URETERS
3-ONE URINARY BLADDER
4- ONE URETHRA

2. THE RENAL HILUM External Anatomy of the Kidneys
A typical adult kidney is:
10–12 cm long
5–7 cm wide
It has a concave medial border
Near the center of the concave border is
THE RENAL HILUM
through which the ureter emerges from the kidney
along with blood vessels, lymphatic vessels, and nerves
Three layers of tissue surround each kidney
The deep layer,
the renal capsule
The middle layer,
the adipose capsule
The superficial layer,
the renal fascia

3. Internal Anatomy of the Kidneys
A frontal section through the kidney reveals two distinct regions:
1-a superficial, called the renal cortex
2-deep, inner region called the renal medulla
The renal medulla consists of several
cone-shaped renal pyramids.
Each pyramid has a base (wider end) faces the renal cortex, and an apex (narrower end), called a renal papilla, points toward the renal hilum
The renal cortex extends from the renal capsule to the bases of the renal pyramids and into the spaces between them.
Those portions of the renal cortex that extend between renal pyramids are called renal columns
The functional units of the kidney—about 1 million microscopic structures called NEPHRONS

4. Nephrons are the functional units of the kidneys.
The Nephron
Parts of a Nephron
Nephrons are the functional units of the kidneys.
consists of two parts:
1-a renal corpuscle
where blood plasma is filtered,
And
2- a renal tubule into which the filtered fluid passes.
The
two components of a renal corpuscle are the
a-glomerulus (capillary network) and the
b-glomerular (Bowman’s)
Capsule
a double-walled epithelial cup that surrounds the
glomerular capillaries.
Blood plasma is filtered in the glomerular
capsule, and then the filtered fluid passes into the renal tubule,

5. THE RENAL TUBULE CONSISTS OF
1) proximal convoluted tubule
2) loop of Henle (nephron loop)
3) distal convoluted tubule
The distal convoluted tubules of several nephrons empty into a single collecting duct.
Collecting ducts then unite and converge
into several hundred large papillary ducts
papillary ducts drain into the minor calyces
and major calyces
Each kidney has 8 to 18 minor calyces and 2 or 3 major calyces.
From the major calyces, urine drains into a single large cavity
called the renal pelvis and then out through the
ureter to the urinary bladder

6. STORAGE, AND ELIMINATION Locations of the urinary bladder
URINE TRANSPORTATION,
STORAGE, AND ELIMINATION
Locations of the urinary bladder
Ureters
Each of the two ureters transports urine from the renal pelvis of one kidney to the urinary bladder.
The ureters are 25–30 cm long
Urinary Bladder
The urinary bladder is a hollow, muscular organ
situated in the pelvic cavity posterior to the pubic symphysis.
Urinary bladder capacity averages 700–800 mL
in females, it is anterior
to the vagina and inferior to the uterus In
males, it is directly anterior to the rectum;

7. In females, it has a length of 4 cm
Urethra
The urethra is a small tube leading from the internal urethral orifice in the floor of the urinary bladder to the exterior of
the body.
In females, it has a length of 4 cm
The opening of the urethra to the exterior, the external urethral orifice, is located between the clitoris and the vaginal opening
Very Short …easily can be infected
In males, the urethra also extends from the internal urethral
orifice to the exterior, but its length and passage through the body
are considerably different than in females
The male urethra first passes through the prostate, then through the
deep muscles of the perineum, and finally through the penis, a
distance of about 20 cm

8. A Foley catheter is a flexible tube that is often passed through the urethra and into the bladder.