Module 5: Excretion

Question 1

Define the term excertion

Answer 1

Removal of unwanted toxic waste proudcts of metabolism like co2, urea etc

Question 2

What is the main function of the liver

Answer 2

break down metabloic waste proudcts and other substances that can be harmful

roles
deamination

Question 3

What is the role of the hepatic atery

Answer 3

brings oxygenated blood from the heart to the liver

Question 4

What is the role of the hepatic portal vein

Answer 4

brings blood from the duodenum and ileum of small intestine, has the products of digestion in blood

Question 5

What is the role hepatic vein

Answer 5

takes deoxyganted blood away from the liver

Question 6

What is the role of bile duct

Answer 6

takes bile to the gall bladder to be stored

Question 7

What is the liver made up of

Answer 7

Liver nobules

Question 8

What are sinusoids

Answer 8

types of capilaries found in liver

Question 9

What is a hepatacyte and its role

Answer 9

Liver cell

roles: produce bile,

Question 10

What is the role of kupffer cells

Answer 10

remove bacteria and breakdown red blood cell

Question 11

What is the role of the bile canaliculi

Answer 11

tubes that drain bile into the bile duct

Question 12

How are excess amino acids broken down

Answer 12

1. Amine group are removed from excess amino acids, forming ammonia and organic acids
2. This is known as deamination
3. organic acids can respired to give ATP or can be converted into carbohydrates and then into glycogen
4. Ammonia is combined with CO2 in the orinithine cycle to make urea and water
5. urea is released from liver into the blood, this is filtred out by kidneys

Question 13

What is detoxification

Answer 13

liver breaks down harmful substances into less harmful substances so it can be excreted from the body

Question 14

Give three examples of harmful substances the liver breaks down

Answer 14

Alcohol: broken down by liver into ethanal and then into acetic acid, excess alcohol consumption can lead to cirrhossis (liver cells die and scar tissue blocks blood flow)

Paracetamol: excess can lead to liver and kidney failure

Insulin

Question 15

What are the different parts of the kidney?

btw you need to know the gross structure

Answer 15

renal artery
renal vein
cortex
medulla
renal calyx
renal capsule

other structures: ureter, baldder, uretha

Question 16

How does a pregnancy test detect a pregnancy

Answer 16

human chorionic gonadotrophin / hCG ;
2 hormone small so can pass from blood into filtrate
3 monoclonal / immobilised ,
antibodies / immunoglobulin , on stick ;
4 antibodies attached to , marker / dye ;
5 hormone , binds / complementary , to antibody ;
6 (triggers) appearance of colour / line becomes visible

Question 17

Describe the features of the glomerulus and Bowman’s capsule that allow them to perform their function effectively.

Answer 17

ultrafiltration ;
2 afferent arteriole is wider than efferent arteriole ;
3 high blood pressure in glomerulus /
high(er) hydrostatic pressure in glomerulus
(than in Bowman’s capsule) ;
4 idea that endothelium / wall of capillary , has gaps to ,
allow / prevent , passage (of substances / cells) ;
5 idea that basement membrane stops removal of ,
large molecules / cells ;
6 podocytes / epithelial cells of Bowman’s capsule ,
have (finger-like) projections / processes ;
7 (projections) ensure gaps to allow passage
(of substances)

Question 18

Explain the loop of henles role during Urine production

Answer 18

1 role of loop of Henle is to
cause a decrease in water potential in
establish water potential gradient going down , medulla ;
2. in the ascending limb active transport outwards of ,
solutes / (sodium and chloride) ions ;
3 (walls of) descending limb are permeable to water ;
4 water removed from descending limb ;
5 water potential of tissues surrounding collecting duct is low(er) than fluid inside it ;
6 water removed from , filtrate / urine (in collecting duct) ;