1. Lecture 24
Urinary System

2. Urinary System Anatomy
Anterior
Kidney
Stomach
Pancreas
Large intestine
Ureter
Liver
Abdominal aorta
Renal vein
Inferior vena
cava
Renal artery
Right kidney
Renal hilum
Fibrous capsule
Spleen
Fat
Urinary bladder
Rib
Left kidney
Fig. 27.2
Urethra
Posterior
(a) Anterior view
Fig. 27.1
External Anatomy of Kidneys
Renal capsule
surrounds each kidney
Hilum
renal artery and nerves enter and renal vein and ureter exit kidneys

3. Internal Anatomy of Kidneys
Renal cortex: Outer area
Renal columns
Renal medulla: Inner area
Renal pyramids
Calyces
Major: Converge to form renal pelvis
Minor: Collects urine from individual renal pyramid
Nephron: Functional unit of kidney
Fig. 27.3

4. The Nephron Renal corpuscle Arterioles Tubules Collecting ducts
Bowman’s capsule
Glomerulus
network of capillaries
Arterioles
Afferent
blood to glomerulus
Efferent
drains
Tubules
Proximal (convoluted) tubule
Loops of Henle
Descending limb
Ascending limb
Distal (convoluted) tubule
Collecting ducts
Fig. 27.5

5. Ureters and Urinary Bladder
tubes through which urine flows from kidneys to urinary bladder
Urinary bladder
stores urine
Urethra
transports urine from bladder to outside of body
difference in length between males and females
sphincters
Internal urinary
External urinary
Ureter
Peritoneum
Ureteral openings
Neck of urinary bladder
Internal urethral
sphincter
External urethral sphincter
Fig. 27.9

6. Review Question
Think back for a moment to the lectures on histology. What type of epithelium would line the inside of the ureters and urinary bladder?
Stratified squamous
Pseudostratified columnar
Simple cuboidal
Transitional
Simple squamous

7. Points to Remember
Kidney filters blood to eliminate metabolic wastes (e.g. urea formed from ammonia that is removed from blood by liver) and reabsorb substances such as sugars, amino acids, sodium and chloride
Functional unit of kidney is nephron
Ureters, urinary bladder and urethra transport urine (product of nephron) outside of body

8. Questions?