Blood and coagulation

Question 1

3 types of blood vessels

Answer 1

arteries, veins, capillaries

Question 2

Arteries

Answer 2

take blood away from heart (except pulmonary artery), elastin and smooth muscle in their walls to withstand high blood pressure, connective tissue on the outside to connect it to structures around it

Question 3

3 layers in veins and arteries

Answer 3

tunica externa/adventitia, tunica media, tunica intima

Question 4

Vaso, vasodilation, vasoconstriction

Answer 4

blood vessel, expansion, contraction

Question 5

Layers in the arteries

Answer 5

Thick tunica media to allow for expansion of the artery as blood is pumped through under high pressure

Question 6

Layers in the veins

Answer 6

Blood in veins has a lower pressure meaning the tunica media is thinner,

Question 7

Veins

Answer 7

Take blood to the heart (except for pulmonary veins)

Question 8

Capillaries

Answer 8

one cell thick meaning only one layer, blood slows when going through the capillaries

Question 9

Blood

Answer 9

Composed of plasma and formed elements

Question 10

Plasma

Answer 10

55% of blood volume, 91% water, 9% dissolved substances such as nutrients

Question 11

Erythrocytes

Answer 11

Red blood cells, biconcave and don’t contain a nucleus, mitochondria or Golgi body which increases the surface area and volume allowing for it to contain haemoglobin, live for 120 days

Question 12

Leucocytes

Answer 12

White blood cells, very large with an obvious nucleus, different types with specific roles, Neutrophils (most common)- engulf and digest pathogens, B and T lymphocytes and natural killer cells- involved in immune response

Question 13

Thrombocytes

Answer 13

Platelets, small cell fragments, lack a nucleus, made in bone marrow, live for 7 days

Question 14

Transport of oxygen in the blood

Answer 14

3% dissolved in the blood, 97% carried in oxyhaemoglobin= haemoglobin (Hb) + oxygen (O2)—–> oxyhaemoglobin (HbO2)

Question 15

Oxyhaemoglobin

Answer 15

High proportion in oxygenated blood, forms in the capillaries surrounding the alveoli, breaks down into oxygen and haemoglobin near body cells so they can take them in

Question 16

Transport of carbon dioxide in the blood

Answer 16

8% dissolved in the blood, 22% carried attached to the haemoglobin= carbamino haemoglobin, 70% carried as a bicarbonate ion

Question 17

Bicarbonate ions

Answer 17

Carbon dioxide combines with water in the plasma to form carbonic acid, carbonic acid breaks down into hydrogen ions and bicarbonate ions= CO2 +H2O H2CO3 H+ + HCO3- (can be reversed near the lungs to produce carbon dioxide to be exhaled), forms near the cells,

Question 18

Blood coagulation

Answer 18

Formation of a blood clot to stop bleeding from damaged blood vessels, blood loses its fluid consistency and becomes a clot

Question 19

Clot

Answer 19

Semi-solid mass formed mostly from platelets, and fibres called fibrin

Question 20

3 basic steps of coagulation

Answer 20

1. Damaged cells of injured blood vessels release ADP which attracts and activates platelets and causes them to clump together to form a platelet plug, 2. Platelets that come in contact with exposed collagen of the damaged blood vessel degranulate releasing more ADP, serotonin (vasoconstrictor) and platelet factors that initiate coagulation, 3. Enzyme called thrombin converts fibrinogen (soluble protein) into fibrin (insoluble thread-like protein) which forms a mesh-like network with erythrocytes and plasma, forming a clot to form a seal in the blood vessel