B4 - The Blood

Question 1

What is the human circulatory system?

Answer 1

• The blood, blood vessels and heart which transports substances to and from the body cells.

Question 2

What is plasma?

Answer 2

• 55% of the blood capacity.

- Blood cells suspended in it and transports proteins and other chemicals around the body.

Question 3

What are red blood cells?

Answer 3

• 45% of the blood capacity.

- Contains haemoglobin that binds to oxygen to transport it from the lungs to the tissues.

Question 4

What are white blood cells?

Answer 4

• <1% of the blood capacity.

- Help to protect the body against infection.

Question 5

What are platelets?

Answer 5

• <1% of the blood capacity.

- Cell fragments that start the clotting process at wound sites.

Question 6

Characteristics of an artery.

Answer 6

• Small lumen, thick layer of muscle and elastic fibres and thick walls.
• Carry oxygenated blood away from the heart.

Question 7

Characteristics of a vein.

Answer 7

• Large lumen, often have valves and relatively thin walls.

- Carry deoxygenated blood to the heart.

Question 8

Characteristics of a capillary.

Answer 8

• Walls a single cell thick and tiny cells with narrow lumen.
• Substances diffuse in and out of the blood in the capillaries.

Question 9

Why are the valves important?

Answer 9

• Prevent back-flow ensuring blood flows in the right direction.

Question 10

Human beings circulatory system.

Answer 10

• They have a double circulatory system.

Question 11

What are the 4 chambers of the heart?

Answer 11

• Left and right atriums, top of the heart.

- Left and right ventricles, bottom of the heart.

Question 12

What is the function of the aorta and where is it located?

Answer 12

• Carries oxygenated blood around the body and is located above the left atrium.

Question 13

What is the function of the pulmonary vein and where is it located?

Answer 13

• Brings oxygenated blood from the lungs and is located in the left atrium.

Question 14

What is the function of the vena cava and where is it located?

Answer 14

• Brings deoxygenated blood into the heart and is located in the right atrium.

Question 15

What is the function of the pulmonary artery and where is it located?

Answer 15

• Takes deoxygenated blood to the lungs and is located above the right atrium.

Question 16

What do ventricles do?

Answer 16

• Pump blood out of the heart.

Question 17

What does blood do when coming into the atria?

Answer 17

• Comes through the valves to the ventricles and then out via the arteries.

Question 18

What is the heart?

Answer 18

• The heart is an organ that pumps blood around the body.

Question 19

What are stents used for?

Answer 19

• To keep narrowed or blocked arteries open.

Question 20

What are statins used for?

Answer 20

• Reduce cholesterol levels in the blood, reducing the risk of coronary heart disease.

Question 21

How can damaged heart valves be replaced?

Answer 21

• Using biological or mechanical valves.

Question 22

How is the resting heart rate controlled?

Answer 22

• By a group of cells in the right atrium that form a natural pacemaker.

Question 23

What are artificial pacemakers?

Answer 23

• Electrical devices used to correct irregularities in the heart rhythm.

Question 24

What are artificial hearts occasionally used for?

Answer 24

• To keep patient alive while they wait for a transplant or for their heart to rest as an aid to recovery.

Question 25

Where are the lungs?

Answer 25

• The lungs are in your chest cavity protected by your ribcage and separated from your abdomen by the diaphragm.

Question 26

What is the alveoli good for in gas exchange process?

Answer 26

• Provide a large surface area and a rich supply of blood capillaries.
• Means gases can diffuse into and out of the blood as efficiently as possible.

Question 27

Order from top - bottom of tissues in the leaf.

Answer 27

• Upper Epidermis
• Waxy Cuticle
• Palisade Mesophyll
• Spongy Mesophyll
• Guard Cells (in the lower epidermis)
• Stomata (in the lower epidermis)

Question 28

What does the epidermal tissue do in the plant?

Answer 28

• Covers the plant.

Question 29

What does the phloem do in the plant?

Answer 29

• Transports dissolved foods from the leaves to the rest of the plant including the growing regions and the leaves.

Question 30

What does the xylem do in the plant?

Answer 30

• Transports water and minerals ions from the roots to the stem and leaves.

Question 31

What does the mesophyll tissue do in the plant?

Answer 31

• Carries out photosynthesis.

Question 32

What happens in the palisade mesophyll?

Answer 32

• There is many chloroplasts located here for photosynthesis.

Question 33

What happens in the spongy mesophyll?

Answer 33

• Big surface area on these cells for gas exchange.

- Big air spaces.

Question 34

What does the stomata do in the plant?

Answer 34

• Allow gases and water to move in and out of the leaf.

Question 35

What do the guard cells do in the plant?

Answer 35

• Control the opening and closing of the stomata.

Question 36

What are plant tissues?

Answer 36

• Collections of cells specialised to carry out specific functions.

Question 37

What is in the plant organ system?

Answer 37

• The roots, stem and leaves form to transport the substances around the plant.

Question 38

What is transpiration?

Answer 38

• Loss of water vapour from the surface of plant leaves is known as transpiration.
• More rapid in hot, dry, windy, or bright conditions.

Question 39

How is water lost in the plant?

Answer 39

• Stomata opens to let water out and carbon dioxide in for photosynthesis.

Question 40

What factors increase the rate of photosynthesis which will then act on the rate of transpiration?

Answer 40

• Temperature, humidity, air flow and humidity.