HCS

Question 1

What are the functions of blood

Answer 1

Transport medium for red blood cells, white blood cells, nutrients and waste materials
Protection against pathogens
Protection against loss of blood through blood clotting
Regulate body temperature, pH, water content of cells

Question 2

What is plasma made up of

Answer 2

90% water
10% proteins and other dissolved substances

Question 3

Function of plasma

Answer 3

Transport water, proteins, dissolved substances, platelets, and blood cells around the body

Question 4

How does a biconcave shape help a red blood cell

Answer 4

Increases surface area to volume ratio -> increases rate of diffusion of oxygen

Question 5

How does an absence of nucleus help a red blood cell

Answer 5

Allows more haemoglobin to be packed -> transport more oxygen

Question 6

State 3 characteristics of white blood cells

Answer 6

• Circular/oval/irregular shape
• Contains nucleus
• Some able to move, change its shape or squeeze through narrow capillaries

Question 7

Function of white blood cells

Answer 7

• Produce antibodies that identify and neutralize pathogens
• Engulf pathogens

Question 8

What are platelets

Answer 8

Membrane bound fragments of cytoplasm from the bone marrow

Question 9

Why are platelets not true cells

Answer 9

No nucleus

Question 10

What to platelets contain

Answer 10

Clotting factors and enzymes to help blood clotting

Question 11

What is the function of platelets

Answer 11

Involved in the process of blood clotting which is crucial in preventing excessive bleeding

Question 12

Function of artery

Answer 12

Transport blood away from the heart

Question 13

Function of veins

Answer 13

Transport blood towards heart

Question 14

Function of capillaries

Answer 14

Allow exchange of oxygen, carbon dioxide, nutrients and waste products between tissue fluid and blood by diffusion

Question 15

Thickness of artery walls

Answer 15

Thick, muscular walls with smaller lumen relative to diameter

Question 16

Thickness of vein walls

Answer 16

Thin, muscular walls with larger lumen relative to diameter

Question 17

Thickness of capillary walls

Answer 17

One-cell thick walls

Question 18

Why do capillary walls have such a thickness

Answer 18

Reduce the distance over which diffusion occurs to increase rate of diffusion

Question 19

Why is the rate of blood flow in capillaries slow

Answer 19

To allow diffusion to take place effectively

Question 20

How does the circulatory system pump blood from the feet to the heart against gravity

Answer 20

Contraction of skeletal muscles compressing the veins

Question 21

What is the role of tissue fluid

Answer 21

Allow diffusion of oxygen and glucose from capillaries to cells and diffusion of carbon dioxide and waste products from cells to capillaries

Question 22

Where and why do heart muscles need energy

Answer 22

Get energy from oxygen and glucose through respiration
Need energy for contraction

Question 23

Where do heart muscles get their supply of oxygen and glucose

Answer 23

Coronary arteries that branch off aorta supply heart with oxygenated blood and glucose

Question 24

What does an unhealthy lifestyle cause

Answer 24

Build-up of fatty deposits along the walls of coronary arteries -> narrows lumen -> reduces blood supply -> block coronary artery significantly -> heart starved of oxygen and glucose -> tissue death -> heart attack

Question 25

Why is it when one survives a heart attack their heart still beats faster than before

Answer 25

Rest of healthy heart muscles need to pump blood faster to compensate for damaged heart muscle

Question 26

Risk factors of Coronary Heart Disease

Answer 26

Poor diet: diet high in fats and cholesterol
Poor lifestyle: smoking, lack of exercise, stress
Genetic factors: family history of heart disease