[HCS] human circulatory system

Question 1

what are the four primary functions of blood?

Answer 1

• transport medium for oxygen, carbon dioxide, nutrients and waste products
• provides protection against pathogens through white blood cells
• provides protection against blood loss through blood clotting
• regulates pH

Question 2

what are the major components of blood, and their respective percentages?

Answer 2

plasma (55%)
red blood cells (45%)
white blood cells and platelets

Question 3

what is the composition of plasma?

Answer 3

• approximately 90% water
• about 10% proteins (including antibodies, enzymes, dissolved substances such as salts, glucose, amino acids and waste products like carbon dioxide and urea)

Question 4

what is the primary role of red blood cells?

Answer 4

red blood cells transport oxygen to other body cells

Question 5

how does oxygenated blood differ from deoxygenated blood in terms of colour?

Answer 5

oxygenated blood: bright red
deoxygenated blood: dark red

Question 6

what is the red colour of blood due to?

Answer 6

heme, a component of haemoglobin

Question 7

what adaptations do red blood cells have for their function?

Answer 7

• biconcanve shape increases surface area to volume ratio, enhancing the rate of diffusion of oxygen
• absence of nucleus allows more space for haemoglobin
• haemoglobin combines reversible with oxygen

Question 8

what are white blood cells?

Answer 8

white blood cells are immune cells

Question 9

what are the key characteristics of white blood cells?

Answer 9

• they contain a nucleus
• the are capable of moving, changing shape and squeezing through narrow capillaries

Question 10

what are the two types of white blood cells?

Answer 10

lymphocytes and phagocytes

Question 11

what are the functions of lymphocytes and phagocytes?

Answer 11

lymphocytes - identify and neutralise pathogens
phagocytes - engulf pathogens

Question 12

what are platelets?

Answer 12

they are membrane-bound fragments of cytoplasm from the bone marrow

Question 13

what is the role of platelets?

Answer 13

they contain clotting factors and enzymes needed for blood clotting and are highly adhesive, sticking to damaged cell surfaces

Question 14

describe the process of blood clotting

Answer 14

1. platelets form a platelet plug at the wound site
2. enzymatic reactions triggered by damaged tissue and platelets form a mesh, trapping blood cells and bacteria
3. the clot solidifies into a scab, protecting underlying layers during cell regeneration

Question 15

what are the four human blood groups?

Answer 15

A,B,AB,O

Question 16

what are blood group O and AB considered as?

Answer 16

O- universal donor
AB- universal recipient

Question 17

what are the main blood vessels?

Answer 17

artery, vein and capillary

Question 18

what is the function of the artery?

Answer 18

it transports blood away from to heart

Question 19

what is the function of the vein?

Answer 19

it transports blood towards the heart

Question 20

what is the function of the capillary?`

Answer 20

it allows for the exchange of oxygen,carbon dioxide, nutrients and waste products between tissue fluid and blood by diffusion

Question 21

what is the purpose of the thick, elastic and muscular wall of arteries?

Answer 21

to withstand the high pressure of blood flow

Question 22

what is the role of valves in veins?

Answer 22

they prevent back flow of blood, helping push blood back to the heart, aided by the contraction of surrounding skeletal muscles

Question 23

what is tissue fluid?

Answer 23

it is an intermediary between blood and body cells

Question 24

what is the role of tissue fluid in nutrient exchange?

Answer 24

it allows material to diffuse from capillaries to cells and vice versa
- the materials include oxygen, nutrients, carbon dioxide and waste products

Question 25

what are the main blood vessels of the heart?

Answer 25

aorta, pulmonary artery, pulmonary vein and vena cava

Question 26

what is coronary heart disease?

Answer 26

it is the result of fatty deposits along the coronary arteries, narrowing the lumen and reducing blood supply to the heart muscle

Question 27

what causes coronary heart disease?

Answer 27

poor diet, lifestyle and genetics

Question 28

what are examples of poor diet?

Answer 28

consuming foods high in cholesterol and fats

Question 29

what are examples of a poor lifestyle?

Answer 29

smoking, lack of exercise and stress

Question 30

what is an example of genetic factors?

Answer 30

having a family history of heart disease