The kidney

Question 1

what is the main function of the kidneys?

Answer 1

to excrete waste products, such as urea. regulate the water potential of blood

Question 2

Describe the process of Ultrafiltration

Answer 2

As the blood passes through capillaries in the cortex (outer layer) of the kidneys, substances are filtered out of the blood and into long tubules that surround the capillaries

Question 3

What is selective reabsorption

Answer 3

Useful substances, such as glucose and the right amount of water, are then reabsorbed back into the blood.

Question 4

What happens to the unwanted substances

Answer 4

unwanted substances pass along to the bladder and are excreted as urine.

Question 5

what are nephrons

Answer 5

long tubules along with the bundle of capillaries where the blood is filtered

Question 6

How many nephrons in the kidney

Answer 6

one million

Question 7

describe the first stages of how blood is filtered at the start of the Nephrons

Answer 7

Blood from the renal artery enters smaller arterioles in the cortex of the kidney. Each arteriole splits into a structure called a glomerulus

Question 8

What is the glomerulus? and what is a bowman’s capsule?

Answer 8

A bundle of capillaries looped inside a hollow ball called a Bowman’s capsule. Top part of the nephron that encloses the glomerulus. This is where Ultrafiltration takes place

Question 9

Describe the process of Ultrafiltration 5 steps

Answer 9

1. Blood enters from the renal artery into smaller arterioles
2. The afferent arteriole takes blood to the glomerulus
3. High pressure forces out liquid and small molecules into the Bowman’s capsule
4. The liquid and small molecules pass through three layers to get into the Bowman’s capsule and enter the nephron tubules and the epithelium of the Bowman’s capsule.
5. Larger molecules like proteins and blood cells can’t pass through, so stay in the blood. The substance that enter the Bowman’s capsule are known as the glomerular filtrate.

Question 10

What happens at the glomerular filtrate and the last stage of Ultrafiltration

Answer 10

The glomerular filtrate passes along the rest of the nephron and useful substances are reabsorbed along the way Finally, the filtrate flows through the collecting duct and passes out of the kidney along the ureter

Question 11

———–are reabsorbed along the Nephron Tubules

Answer 11

Useful

Question 12

Where does selective reabsorption take place

Answer 12

at the glomerular filtrate flows along the proximal convoluted tubule (PCT), through the loop of Henle, and along the distal convoluted tubule (DCT).

Question 13

Describe the process of selective reabsorption

Answer 13

1) Useful substances leave the tubules of the nephrons and enter the capillary network that’s wrapped around them
2) The epithelium of the wall of the PCT has microvilli to provide a large surface area for the reabsorption of useful materials from the glomerular filtrate (in the tubules) into the blood (in the capillaries).
3) Useful solutes, like glucose, are reabsorbed along the PCT by active transport and facilitated diffusion.
4) Water enters the blood by osmosis because the water potential of the blood is lower than that of the filtrate. Water is reabsorbed from the PCT, loop of Henle, DCT and the collecting duct
5) The filtrate that remains is urine, which passes along the ureter to the bladder.

Question 14

What is Urine made up of

Answer 14

Wter and dissolved salts

Urea

hormones and excess vitimins

Question 15

What doesnt Urine normally contain

Answer 15

Protein and blood(To big to filter)

Gluecose becouse they are actively reabsorbed back into blood