[Part 2]- B4- Organising animals and plants 🫀🪴

Question 1

What is the structure + function of arteries [2]

Hint: carry blood at a high pressure.

Answer 1

• arteries carry very high pressure blood away from the heart + to the organs in the body.
• they have very thick muscular walls, allowing them to withstand the very high pressure of the blood.

Question 2

What is the structure and function of arteries ? [2]

Hint: small, arteries in surges

Answer 2

• Because blood travels through the arteries in surges, every time the heart beats, arteries have elastic fibres.
• these elastic fibres stretch when the surge of blood passes through and then recoil in between the surges- this keeps the blood moving.
• they also have a small lumen

Question 3

Discuss the function + structure of capillaries [2]

Hint: lumen, blood cells and ______.

Answer 3

• capillaries have very thin walls [because they are one-cell thick]- which means there is a short diffusion distance, therefore substances can diffuse rapidly between the blood and the body cells.
• For example, there is a short diffusion distance to move between blood cells and tissue.
• capillaries also have a very narrow lumen.

Question 4

Discuss the function +structure of veins [2]

Hint: large

Answer 4

• Veins carry blood towards the heart and have a wide/large lumen
• ; they also have a thin wall [as they are one-cell thick.] This is because the blood pressure is low, so the wall [of veins] doesn’t need to be thick.

Question 5

Discuss the function +structure of veins [2]

Hint: valves

Answer 5

• many veins also contain valves, which the role of them, is to stop blood from flowing backwards [and instead flow in the correct direction.]
• When the blood is flowing in the correct direction, the valves then open, allowing the blood to flow through; when the blood starts to flow backwards, the valves shut.

Question 6

What are the four components of blood?

Answer 6

• red bloods cells
• white blood cells
• platelets- tiny fragments of cells
• plasma- the liquid part of the blood, containing two different types of blood cells.

Question 7

What is plasma ?

Answer 7

• plasma, is known as the liquid part of the blood, which contains two different types of blood cells, as it also transports dissolved substances around the body

Question 8

What is urea ?

Answer 8

• transported from the liver to the kindeys, and excreted in urine, urea is a waste-product [that is filtered out of the blood as it is poisonous.]
• and is produced from the breakdown of excess amino acids in the liver.

Question 9

What are red blood cells ?

Answer 9

• red blood cells transport oxygen from the lungs to the body cells

Question 10

What are the three adaptations of red blood cells ? [3]

Answer 10

• red blood cells contain the oxygen-carrying molecule, known as haemoglobin
• red blood cells have no nucleus.
• red blood cells have a dimple in the centre of the cell, known as a biconcave disc to scientists.

Question 11

What are white blood cells ?

Hint: form

Answer 11

• white blood cells form part of the immune system [by making antibodies] contain a nucleus.
• their nucleus contains DNA, which encodes the instructions that the white blood cells need to do their job.

Question 12

What are platelets ?

Answer 12

• Platelets are tiny fragments of cells, and their job is to help the blood to clot

Question 13

What are the uses of donated blood uses in medicine ?

Answer 13

• to replace blood during injury
• some people are given platelets, that are extracted from blood to help in clotting
• and proteins extracted from the blood, can be useful [e.g- antibodies]

Question 14

What are the problems of using donated blood ?

Answer 14

• in a blood transfusion, the donated blood has to be the same blood type as the patient’s, otherwise the body’s immune system would reject the blood= the patient will die.
• risk of infection: lots of different diseases can be transmitted via the blood; in the UK, blood is screened for infections= the risk is extremely low.

Question 15

What are cardiovascular diseases ?

Answer 15

• Cardiovascular diseases, are diseases of the heart and blood vessels.
• They are non-communicable diseases, meaning they’re not infectious and can’t be passed from person to person

Question 16

What is an example of a cardiovascular disease ?

Answer 16

• An example of a cardiovascular disease is coronary heart disease. [Also known as CHD]

Question 17

What is the purpose of the coronary artery ?

Answer 17

• the purpose of the coronary artery, is to provide oxygen to the muscle cells of the heart.
• [The oxygen is then used in respiration, providing the energy needed for contraction]

Question 19

Explain how CHD can cause a heart attack [3]

Hint: build up, reduces, lack of oxygen

Answer 19

• in CHD, layers of fatty material build up inside the arteries which causes the arteries to narrows.
• this reduces the flow of blood through coronary artery
• resulting in a lack of oxygen for the heart muscle, which can result in a heart attack [where the heart is starved of oxygen.]

Question 19

How can coronary heart diseases be treated ?

Answer 19

• statins- these are drugs which reduce the level of cholesterol in the blood, slowing down down the rate that fatty materials build up in the arteries.
• stents- sometimes, coronary heart disease can cause almost a total blockage of a coronary artery and a tube is inserted into the coronary artery, to keep it open.

Question 20

What are the advantages and disadvantages of statins ? [4] ✅❌

Answer 20

• statins have been proven to reduce the risk of coronary heart disease [they are effective]; statins have unwanted side- effects [such as liver problems]
• statins can increase the type of HDL cholesterol in the blood, which can help to remove LDL cholesterol ; statins are a long-term drug, which means they must be taken regularly and there is a risk, someone could forget to take them.

Question 21

What are some other advantages and disadvantages of statins ? [2] ✅❌

Hint: time

Answer 21

• some studies suggest that statins can help to prevent other diseases; the effect of statins isn’t instant, because it takes time for their effect to kick in.

Question 22

What are the advantages and disadvantages of stents [5] ? ✅❌

Answer 22

• the blood can flow normally throughout the artery; a stent won’t prevent other regions of the coronary artery from narrowing.
• stents are effective for a long-time and the recovery time from the surgery is relatively quick; stents don’t treat the underlying cause of the disease.
• *[ also, there is a risk of: complications during the operation, infection from surgery + patients developing thrombosis- a blood clot near the stent]

Question 23

What does plasma transport ?

Answer 23

• blood plasma transports soluble digestion products [e.g- glucose], from the small intestine to other organs.
• blood plasma also transports carbon dioxide [produced by aerobic respiration] from the organs to the lungs, to be breathed out.
• blood plasma also transports urea from the liver, to be excreted in urine

Question 24

Why do red blood cells have a concave disc ?

Answer 24

• red blood cells have a dimple in the centre of the cell, known as a biconcave disc.
• this shape gives the red blood cell a greater surface area, allowing oxygen to diffuse in and out rapidly.

Question 25

Why do red blood cells have no nucleus ?

Answer 25

• red blood cells have no nucleus to have more room for the large protein, haemoglobin.

Question 26

Why do red blood cells have haemoglobin ?

Answer 26

• *red blood cells contain the oxygen-carrying molecule, known as haemoglobin** which combines with oxygen in the lungs, to form the molecule oxyhaemoglobin.
• the red blood cells then travels to the organs, where the oxyhaemoglobin releases the oxygen.