Unit Assignment

Unit 7 Seminar Option 2

Jalena Johnson

Kaplan University

05 November 2013

Discuss the major components of the urinary system and the formation of urine.

Kidneys

According to our text," The kidneys are vital organs. The function they perform, that of forming urine, is essential for homeostasis and maintenance of life. Early in the process of urine formation, fl uid, electrolytes, and wastes from metabolism are fi ltered from the blood and enter the nephron. Additional wastes may be secreted into the tubules of the nephron as substances useful to the body are reabsorbed into the blood."(Thibodeau 2008)

Urethra

To leave the body, urine passes from the bladder, down the urethra, and out of its external opening, theurinary meatus. In other words, the urethra is the lowest part of the urinary tract. this is a structural feature worth noting because it accounts for the fact that an infection of the urethra may spread upward through the urinary tract. The urethra is a narrow tube; it is only about 4 cm (11⁄2 inches) long in a woman, but it is about 20 cm (8 inches) long in a man. In a man, the urethra has two functions: (1) it is the terminal portion of the urinary tract, and (2) it is the passageway for movement of the reproductive fl uid (semen) from the body. (449)

Bladder

The empty urinary bladder lies in the pelvis just behind the pubic symphysis. When full of urine, it projects upward into the lower portion of the abdominal cavity. In women it sits in front of the uterus, whereas in men, it rests on the prostate. Elastic fibers and involuntary muscle fi bers in the wall of the urinary bladder make it well suited for expanding to hold variable amounts of urine and then contracting to empty itself. A specialized type of epithelial membrane lines the urinary bladder.(450)

Ureters

Urine drains out of the collecting tubules of each kidney into the renal pelvis and down the ureter into the urinary bladder. The renal pelvis is the basin-like upper end of the ureter...