The Liver and Excretion

Question 1

1

Define excretion

Answer 1

the reemoval of waste products of metabolism from the body

Question 2

2

define metabolism

Answer 2

all chemical reactions that happen in the cells

Question 3

4

what does liver break down?

Answer 3

amino acids

Question 3

6

what happens to amino acids in the body?

Answer 3

they are either used to make proteins or are broken down or excreted.

Question 4

3

what are the waste products produced by the cells?

Answer 4

carbon dioxide and nitrogenous waste , most of which are toxic

Question 5

10

define detoxification

Answer 5

when harmful substances are broken down into less harmful compounds

Question 5

7

how are amino acids broken down by the liver?

4 steps of the ornuthine cycle

Answer 5

1. nitrogen containinf amino groups are removed (deaminiation) from excess amino acids and form ammonia and organic acids
2. organic acids are respred to give ATP or converted to carbohdrates to be stored as glycogen.
3. ammonia is to toxic for mammals to excrete directly so its combined with co2 in the ornithine cycle and creates urea.
4. the urea is released into the blood and the kidneys filter it from the blood to remove it as urine

Question 5

5

why does the liver break down amino acids?

Answer 5

they contain nitrogen in their amino groups and so cant be stored by the body so an excess is damaging

Question 6

9

what harmful substance does the liver break down?

Answer 6

alcohol
drugs
unwanted hormones

Question 6

8

which part of the ornithine cycle occurs in the mitochondria of the liver cells?

Answer 6

ornithine convertion to citruline through ammonia + co2 = carbaroyl phosphate

Question 7

11

what is alcohol broken down to?

Answer 7

damages cells so broken down to ethanol and then to acetic acid

Question 8

12

what does excess alcohol cause in the liver?

Answer 8

cirrhosis - cells of the liver die and scar tissue blocks blood flow.

Question 9

14

which hormone is broken down by the liver

Answer 9

insulin

Question 10

15

liver converts excess glucose into

Answer 10

glycogen

Question 10

13

why is paracetamol broken down

Answer 10

excess leads to liver and kidney failure

Question 11

16

function of hepatic artery?

Answer 11

supplies the liver with oxygenated blood from the heart so the liver had a good supply of oxygen for respiration

Question 11

17

function of hepatic vein?

Answer 11

takes deoxygenated blood away from the liver

Question 12

18

function of hepatic portal vein?

Answer 12

brings blood from the duodenum and ileum so its rich in products of digestion so any ingested or harmful substances can be broken down straight away.

Question 13

19

bile duct function

Answer 13

takes bile to the gall bladder to be stored

Question 14

20

what is bile

Answer 14

a substance produced by the liver which emulsifies fats

Question 15

21

what are liver lobules?

Answer 15

cylindirical structures made of cells called hepatocytes that are arranged in rows radiating out from the centre

Question 16

22

what in the lobule connects to the hepatic vein

Answer 16

central vein

Question 17

23

what are connected to liver lobules

Answer 17

many brances of the hepatic portal vein, hepatic arteyr and bile ducts.

Question 18

24

how are hepatic arteries and veins connected to the central vein?

Answer 18

capillaries called sinusoids

Question 19

blood runs through sinusoids and past hepatocytes, which do what?

Answer 19

remove harmful substances and oxygen from the blood.

Question 20

26

harmful substances are broken down by

Answer 20

hepeatocytes into less harmful substances which re enter the blood.

Question 21

27

central veins from all lobules connect to form

Answer 21

the hepatic vein

Question 22

28

what do kuppfer cells do?

Answer 22

attach to the walls of the sinusoids and remove bacteria and break down old red blood cells.

Question 23

29

hepatocytes produce?

Answer 23

bile

Question 24

30

bile is secreted into

Answer 24

bile canalicili whoch drawn into bile ducts and leave the liver

Question 25

IDENTIFYING LIVER UNDER MICROSCOPE

the large white circular shape is

Answer 25

the central vein

Question 26

IDENTIFYING LIVER UNDER MICROSCOPE

red dots of cells are

Answer 26

the nuclei of hepatocytes

Question 27

IDENTIFYING LIVER UNDER MICROSCOPE

many white spaces are

Answer 27

sinusoids