Urinary System

URINARY SYSTEM NOTES

I. INTRODUCTION

A. The primary function of the urinary system is to help maintain homeostasis by controlling the composition and volume of blood through the removal and restoration of selected amounts of water and solutes. It also eliminates wastes from the body.

B. Among the organs that contribute to the elimination of wastes are the kidneys, lungs, skin, and gastrointestinal tract.

C. The organs of the urinary system are the kidneys, ureters, urinary bladder, and urethra

D. The specialized branch of medicine that deals with structure, function, and diseases of the male and female urinary systems and the male reproductive system is known as nephrology. The branch of surgery related to male and female urinary systems and the male reproductive system is called urology.

II. KIDNEYS

A. External Anatomy; Internal Anatomy

1. The paired kidneys are retroperitoneal organs attached to the posterior abdominal wall

2. Near the center of the concave medial border of the kidney is a notch called the hilus, through

which the ureter leaves and blood vessels, lymphatic vessels, and nerves enter and exit

3. Three layers of tissue surround each kidney: the innermost renal capsule, the adipose capsule, and the outer renal fascia.

4. Nephrotosis (floating kidney) is a downward displacement or dropping of the kidney. Thin persons are most susceptible because their adipose capsule or renal fascia may be deficient, allowing slippage of the kidney from its original position. It is dangerous because the ureter may kink, blocking urine flow and resulting in pressure damage to kidney tissue.

5. Internally, the kidneys consist of a cortex, medulla, pyramids, papillae, columns, calyces, and pelvis

6. The nephron is the functional unit of the kidney.

a. A nephron consists of a renal corpuscle where fluid is filtered, and a renal tubule into which the filtered fluid passes

1. The renal corpuscle has two components: a tuft...