B9.3 & B9.4 - Blood Vessels & Blood

Question 1

What is the muscular wall like for arteries? [1]

Answer 1

thick

Question 2

What is the muscular wall like for veins? [1]

Answer 2

thin

Question 3

What is the muscular wall like for capillaries? [1]

Answer 3

no muscular wall

Question 4

What is the lumen like in arteries? [1]

Answer 4

small

Question 5

What is the lumen like in veins? [1]

Answer 5

large

Question 6

What is the lumen like in capillaries? [1]

Answer 6

very small

Question 7

Does an artery contain valves, why or why not? [2]

Answer 7

• no
• blood is travelling so fast so it won’t go back down

Question 8

Does a vein contain valves? [1]

Answer 8

yes

Question 9

Does a capillary contain valves? [1]

Answer 9

no

Question 10

What is the function of a capillary? [2]

Answer 10

• connect arteries and veins
• allows for exchange of substances between the blood and the cells

Question 11

How is the structure of an artery fit for its function? [4] (2 things with explanation)

Answer 11

• contains thick walls: withstands the high pressure of blood
• has thick layers of elastic tissues: it can stretch and recoil with each surge of blood

Question 12

How is the structure of a vein fit for its function? [6] (3 things with explanation)

Answer 12

• thin walls: blood is at a low pressure
• large lumen: help the blood flow despite the low pressure
• has valves: helps blood flowing in right direction

Question 13

How is the structure of a capillary fit for its function? [2] (1 thing with explanation)

Answer 13

• thin wall made of one cell: diffusion distance is shorter so diffusion rate increases

Question 14

How are capillaries adapted for exchange of substances? [3]

Answer 14

• capillary walls = thin = short diffusion distance
• capillaries are highly branched = large surface area
• capillary beds are supplied with fresh blood = concentration gradient maintained

Question 15

What are the components of blood? [4]

Answer 15

• plasma
• white blood cells
• platelets
• red blood cells

Question 16

What is the function of a red blood cell? [4]

Answer 16

• transport oxygen around the body
• contains haemoglobin
• no nucleus = more space for haemoglobin
• bi concave shape

Question 17

What is the function of white blood cells? [2]

Answer 17

• fights disease by making antibodies
• fights disease by changing shape to engulf microorganisms

Question 18

What are the two types of white blood cells and what does each one do? [4]

Answer 18

• lymphocytes: makes antibodies
• phagocytes: engulf and digests pathogens

Question 19

What is the function of platelets? [2]

Answer 19

• tiny structures
• help the blood clot

Question 20

What is the function of plasma? [4]

Answer 20

• transports dissolved substances
• straw - coloured liquid
• 90%+ of plasma = water
• excess water from large intestines goes to kidneys to be removed

Question 21

What things are dissolved in plasma? [5]

Answer 21

• hormones
• urea
• blood cells
• nutrients
• carbon dioxide

Question 22

What is the role of blood clotting? [2]

Answer 22

• preventing blood loss
• preventing entry of pathogens

Question 23

What happens to the speed of blood as if flows through capillaries and why? [2]

Answer 23

• it gets slower
• because there’s a larger surface area so more friction