Renal System

Question 1

What makes us the urinary system?

Answer 1

• 2 Kidneys
• Ureters
• Bladder
• Urethra

Question 2

What are the ureters?

Answer 2

They are tubes that lead from the kidneys and carry urine to the bladder

Question 3

What is the bladder?

Answer 3

Smooth muscle receptacle that stores urine

Question 4

What is the urethra?

Answer 4

A tube that leads from the bladder and drains the urine out of the body. Features two sphincters - internal sphincter in involunatrily while the external in voluntarily

Question 5

Describe the positioning of the kidneys in as much detail as you can

Answer 5

• Bean shaped
• Located between 12th thoracic and 3rd lumber vertebrae
• The right lies low than the left because it is pushed down by the liver
• Cushioned and held in place by fat, renal fascia and abdominal organs
• Blood supply originates from the abdominal aorta and then the renal artery
• Blood travels away from the kidney via renal vein and then the inferior vena cava

Question 6

What are the functions of the kidney?

Answer 6

1. Excretion
2. Homeostatic function
3. Secretion - Hormonal secretory function
4. Endocrine hormonal metabolic function

Question 7

What are the 3 steps in the formation of urine?

Answer 7

1. Filtration
2. Re-absorption
3. Secretion

Question 8

What happens during filtration?

Answer 8

Water and solutes smaller than proteins are forced through the capillary walls and pores of the glomerular capsule into the renal tube

Question 9

What happens during reabsorption?

Answer 9

Water, glucose, amino acids and needed ions are transported out of the filtrate into the tubule cells and then entre the capillary blood

Question 10

What is secretion?

Answer 10

H+, K+, creatinine and drugs are removed from the peritubular blood and secreted by the tubule cells into the filtrate

Question 11

What happens in the Bowman’s capsule?

Answer 11

It revieces the filtrate

Question 12

What happens in the proximal convoluted tubule?

Answer 12

Reabsoption of water and solutes

Question 13

What happens in the Nephron Loop/Loop of Henle

Answer 13

Regulates concentration of urine

Question 14

What happens in the distal convoluted tubule and Collecting duct?

Answer 14

Reabsoption of water and electrolytes, ADH, aldosterone, ANP and tubular secretion

Question 15

Explain how filtration occurs

Answer 15

The difference in diameter between the two arterioles creates a pressure in the glomerular capillaries (filtration pressure)
Small molecules pass through the fenestrations and are captured in the glomerular capsule
Larger molecules remain in the clood stream
The filtered liquid is termed glomerular filtrate
In a healthy adult approximately 120mL/min are formed and this is termed the GLOMERULAR-FILTRATION RATE (GRF)

Question 16

What is tubular reabsorption?

Answer 16

The process by which solutes and water and removed from the tubular fluid and transported into the blood. It is called reabsorption because these substances have already been absorbed once

Question 17

What is tubular secretion?

Answer 17

The transfer of materials from peritubular capillaries into renal tubular lumen. Tubular secretion is caused mainly by active transport.
Usually only a few substances are secreted. These substances are present in great excess or are natural poisons.
Many drugs re eliminated by tubular secretion