9.4 Blood

Question 1

what are the components of blood

Answer 1

-red blood cells
-white blood cells
-platelets
-plasma

Question 2

identify red and white blood cells in diagrams and photomicrographs

Question 3

function of red blood cells

Answer 3

-transport oxygen all around the body
-contains a protein called haemoglobin which binds to oxygen, allowing it to be transported around the body to cells

Question 4

function of white blood cells

Answer 4

-defends the body against infections
-fights off infections by carrying out phagocytosis and antibody production

Question 5

function of platelets

Answer 5

-helps in blood clotting

Question 6

function of plasma

Answer 6

-transports blood cells, ions. nutrients, urea, hormones and carbon dioxide

Question 7

function of phagocytes

Answer 7

-engulfs pathogens by a process called phagocytosis
-when a phagocyte comes across a pathogen, it engulfs it, taking it inwards
-then it releases digestive enzymes on it, which digests the pathogen and destroys it

Question 8

function of lymphocytes

Answer 8

-produces antibodies to attack and destroy pathogens

Question 9

identify phagocytes and lymphocytes in diagrams and photomicrograph

Question 10

role and process of blood clotting

Answer 10

-when an injury takes place, platelets help preventing blood loss by forming blood clots
-platelets are fragments of cells present in the blood
-platelets clump together and form a plug to stop the bleeding
-activates the production of thrombin which causes soluble protein fibrinogen in plasma to convert to insoluble fibrin to form a mesh.
-more platelets stick to this mesh, forming a scab and thereby preventing bleeding
-this block at the cut also prevents pathogens from entering the blood vessel

Question 11

why is blood clotting necessary

Answer 11

-prevent serious blood loss
-prevent the entry of microorganisms and foreign substances into the body through damaged blood vessels
-maintain blood pressure
-maintain the circulation of blood in a closed circulatory system

Question 12

function of water

Answer 12

-makes up about 90% of plasma
-a solvent to transport dissolved substances such as glucose and amino acids
-distribute heat

Question 13

ions (sodium, potassium, magnesium, calcium, chloride, bicarbonate)

Answer 13

maintains osmotic balance and the pH of the blood at 7.4

Question 14

plasma proteins (albumin, fibrinogen, antibodies)

Answer 14

-maintains the osmotic pressure between blood and body fluid
-acts as buffers against any pH changes and provide a defence against injuries and diseases
-clotting factor that helps blood clotting when blood vessels are cut
-antibodies that help in body’s defence

Question 15

function of hormones

Answer 15

controls physiological activities in the body

Question 16

function of dissolved substance (glucose, vitamins, waste products, urea, respiratory gases)

Answer 16

-nutrients are important for the production of energy, growth and maintenance of health
-oxygen is needed during cellular respiration