Excretion

Question 1

What is excretion?

Answer 1

is the removal of toxic substances from the body, the waste products of metabolism and substances that are in excess

Question 2

What effects do excretory substances have on the body?

Answer 2

acidosis is a condition caused by high concentration of carbon dioxide in the blood
ammonia increases the ph in cytoplasm
urea is highly diffusible and passes into cells
uric acid can form crystals in joints causing a form of arthritis called gout
bile pigments

Question 3

How is urea produced?

Answer 3

Ammonia is produced from leftover amino acids, and it must be removed from the body. The liver produces several chemicals that change ammonia into a form called urea, which the body can remove in the urine.
Urea is formed during nitrogen metabolism in our body. Urea formation takes place in the hepatic cells of the liver. Then the urea is released into the bloodstream. The blood reaches the kidney and filteration takes place.

Question 4

What is the functional unit of the kidney?

Answer 4

nephron

Question 5

What does the nephron do in the kidney?

Answer 5

Each nephron includes a filter, called the glomerulus, and a tubule. The glomerulus filters your blood, and the tubule returns needed substances to your blood and removes wastes.

Question 6

What are some features of the kidney that you can see through a light microscope?

Answer 6

glomerulus, loops of henle, proximal convoluted tubules, distal convoluted tubules, collecting ducts

Question 7

What is ultrafiltration?

Answer 7

Ultrafiltration is where large biomolecules such as proteins and sugars are filtered from the blood before the formation of urine.
It occurs under high pressure.
The filtration of blood that occurs through the membranes is so fine that almost all the elements of the plasma, the exception being the proteins move into the lumen of the Bowman’s capsule

Question 8

What is selective reabsorption?

Answer 8

Selective reabsorption is where certain molecules, after being filtered out of the capillaries along with nitrogenous waste products and water in the glomerulus, are reabsorbed from the filtrate as they pass through the nephron.

Question 9

What is the function of the loop of henle?

Answer 9

to reabsorb water and sodium chloride from the filtrate. This conserves water for the organism, producing highly concentrated urine.

Question 10

What is osmoregulation?

Answer 10

Osmoregulation is the process of maintaining osmotic pressure of an organism fluid or balance of the water content in the organisms body

Question 11

What are strips used to test urine for?

Answer 11

glucose- may indicate diabetes
ketones- present if there is not enough glucose to metabolise
albumen- a plasma protein that shouldn’t be filtered in the blood