Excretion

Question 1

What is metabolism?

Answer 1

All the chemical reactions that happen in your cells

Question 2

Why can’t waste products build up in the body?

Answer 2

They are toxic and would cause damage by affecting other metabolic reactions

Question 3

What is excretion?

Answer 3

The removal of the waste products of metabolism from the body

Question 4

What is broken down by the liver?

Answer 4

Excess amino acids

Question 5

Why do excess amino acids need to be broken down?

Answer 5

Amino acids contain nitrogen and nitrogen can’t be stored in the body so they are broken down to prevent damage to the body

Question 6

What occurs in deamination?

Answer 6

Nitrogen containing amino groups (-NH2) removed from excess amino acids - forming ammonia (NH3) and organic acids

Question 7

Why can’t ammonia be excreted directly? How is it excreted?

Answer 7

It is too toxic to be excreted directly, so it is combined with CO2 in the ornithine cycle to create urea

Question 8

Where in the body is ammonia combined with CO2 in the ornithine cycle?

Answer 8

The mitochondria of the liver cells

Question 9

What is alcohol broken down into and where?

Answer 9

Ethanol is broken down by the liver into ethanal

Question 10

What are the four substances broken down by the liver?

Answer 10

1)excess amino acids
2) alcohol
3) paracetamol
4) insulin

Question 11

What part supplies the liver with oxygenated blood from the heart?

Answer 11

The hepatic artery

Question 12

What part takes deoxygenated blood away from the liver?

Answer 12

The hepatic vein

Question 13

What part brings blood from the small intestine, and why?

Answer 13

The hepatic portal vein - it is rich in the products of digestion (no harmful substances also)

Question 14

Where does the bile duct take bile to?

Answer 14

The gallbladder to be stored

Question 15

What is the liver made up of?

Answer 15

Liver lobules - cylindrical structures made of cells called hepatocytes

Question 16

What is in the middle of each lobule in the liver?

Answer 16

Central vein that connects to the hepatic vein

Question 17

What are sinusoids in the liver?

Answer 17

Capillaries in which blood runs through past hepatocytes that remove the harmful substances and oxygen

Question 18

What are the two parts of the liver in which blood runs through that join at the sinusoid to the central vein?

Answer 18

The hepatic artery and the hepatic portal vein

Question 19

What do kupffer cells do and where are they located?

Answer 19

They removed bacteria and breakdown old red blood cells - connected to the walls of the sinusoids

Question 20

What do hepatocytes produce and where does this go?

Answer 20

They produce bile and secreted into the bile canaliculi which drains to the bile ducts

Question 21

Under a light microscope, what does the central vein of the liver look like?

Answer 21

A large white circular shape

Question 22

Under a light microscope, what do hepatocytes in the liver look like?

Answer 22

The largest mass with red nuclei

Question 23

Under a light microscope, what do sinusoids in the liver look like?

Answer 23

Other white spaces that aren’t the central vein

Question 24

What are the two main function of the kidney?

Answer 24

To excrete waste products and regulate water potential of the blood

Question 25

Where does blood enter the kidney?

Answer 25

The renal artery

Question 26

Upon entering the kidney, where does the blood go and what happens to it?

Answer 26

The blood passes through the capillaries and substances are filtered out of the blood

Question 27

What is the name of the process where substances are filtered out of the blood in the kidneys?

Answer 27

Ultrafiltration

Question 28

What is reabsorbed back into the blood from the kidney and why?

Answer 28

Glucose because it is useful

Question 29

Where do the unwanted substances from ultrafiltration go?

Answer 29

Ureter and the bladder to be expelled as urine

Question 30

Once the blood from the kidney has undergone ultrafiltration, where does it go?

Answer 30

Out the kidneys through the renal vein

Question 31

Where does ultrafiltration take place?

Answer 31

The glomerulus that is looped inside the bowmans capsule

Question 32

How do substances move from the capillary into the Bowman capsule?

Answer 32

High pressure forces liquid and small molecules out the blood

Question 33

What are the names of the arterioles before and after the blood enters the glomerulus?

Answer 33

The afferent arterioles and the efferent arteriole

Question 34

Once the substances have entered the Bowman capsule, what path do they travel down?

Answer 34

Through proximal convoluted tubule, the loop of henle and the distal convoluted tubule to the renal vein that heads to the ureter

Question 35

Why can’t larger molecules pass through into the Bowman capsule?

Answer 35

They are too big to pass through the pores in the endothelium

Question 36

What takes place as the filtrate flows along the PCT, loop of Henle and the DCT?

Answer 36

Selective reabsorption

Question 37

What is reabsorbed by the PCT?

Answer 37

Useful solutes (glucose, amino acids and vitamins)

Question 38

What is urine usually made up of?

Answer 38

Water, urea and hormones

Question 39

What doesn’t urine usually contain?

Answer 39

Proteins, blood cells, glucose and amino acids

Question 40

What does the cortex of a nephron look like under a light microscope?

Answer 40

A glomerulus surrounded by a white Bowman capsule which is surrounded by squamous epithelial cells

Question 41

What are the long white lines on a nephron under a light microscope?

Answer 41

Loops of henle