Urinary System

Question 1

What does it mean that the kidneys are retroperitoneal?

Answer 1

Located behind the parietal peritoneum

Question 2

What are general functions of the urinary system?

Answer 2

Filter blood, removing metabolic wastes, toxins, and ions
* Regulate volume and chemical makeup of blood
* Balance water, salts, acids, and bases

Question 3

The main structural and functional unit of the kidney is the ______

Answer 3

The nephron

Question 4

A renal corpuscle is made of what?

Answer 4

glomerular capsule + glomerulus

Question 5

List in order, from renal corpuscle to collecting duct, the parts of the nephron:

Answer 5

proximal convoluted tubule
loop of Henle
distal convoluted tubule
collecting tubule
collecting duct

Question 6

What are some differences between a cortical and a juxtamedullary nephron?

Answer 6

Cortical nephrons
* Make up 85% of all nephrons
* Are located almost entirely within the cortex
* Nephron loops dip into medulla only a short distance
Juxtamedullary nephrons
* Make up 15% of nephrons
* Are called juxtamedullary because the renal corpuscle is near the cortex-medullary border
* Nephron loops dip deeply into medulla
* Long loops help produce concentrated urine

Question 7

What are some differences between peritubular capillaries and the vasa recta?

Answer 7

Peritubular Capillaries
* Surround renal tubules
* Branch from efferent arteriole
* Designed for absorption and secretion
* Very porous
* Cortical nephrons have only peritubular capillaries
Vasa Recta
* Surround only tubules of juxtamedullary nephrons
* Branch from efferent arteriole of these nephrons
* Descend deep into the medulla of kidney
* Involved with concentrating urine

Question 8

List the 3 overall steps of urine formation and indicate (generally) what occurs in each

Answer 8

1. Filtration: Blood is filtered, filtrate is formed
2. Resorption: Substances to keep in the body are returned to blood
3. Secretion: Substances to be removed from the body enter into filtrate

Question 9

What is the glomerular capsule made of (macroscopically)?

Answer 9

• Parietal layer forms outer layer of capsule
• Visceral layer surrounds capillaries

Question 10

Describe the glomerulus and glomerular capsule

Answer 10

Glomerulus: Ball of fenestrated capillaries
Glomerulus capsule: covers glomerulus

Question 11

Which blood vessel enters the glomerulus?

Answer 11

Afferent arteriole

Question 12

What are podocytes and what do they have to do with the glomerular capsule?

Answer 12

The visceral layer is made of unusual, branching epithelial cells
called podocytes

Question 13

Describe the structure of the filtration membrane. What kinds of substances can cross the filtration membrane?

Answer 13

Filtrate passes into capsule space through filtration slits

Question 14

What are the general events that occur in the different regions of the renal tubule and collecting duct? Can you describe the epithelial linings of these regions?

Answer 14

Involved with resorption and secretion
* Na+/K+ pump (sodium resorbed, potassium secreted)
* Cuboidal cells resorb salt, vitamins, water
* Confined to renal cortex
* Made of simple cuboidal epithelium with microvilli

Question 15

What is hemodialysis used for?

Answer 15

Procedure used to cleanse blood when kidneys arent filtrating

Question 16

What is lithotripsy used for?

Answer 16

treats kidney stones by sending focused ultrasonic energy or shock waves directly to the stone

Question 17

What is the name of the smooth muscle lining the urinary bladder? What prompts its contraction?

Answer 17

Detrusor muscle -> when muscle is streched

Question 18

What type of epithelium lines the urinary bladder?

Answer 18

Peritoneum

Question 19

Describe the sphincters that control the retention and release of urine? How do they differ between the sexes?

Answer 19

Female: * Internal urethral sphincter ->Smooth muscle, Keeps urethra closed when urine not passing through
* External urethral sphincter-> Skeletal muscle; voluntary control
Male: same but like 16 cm distance lol