Topic 1: Lifestyle, Health, and Risk Flashcards
Define diffusion.
Diffusion is the movement of particles from high to low concentration.
What is mass flow?
Mass flow is the bulk movement of substances over relatively long distances, due to pressure differences.
What do mass transport systems do?
Mass transport systems move substances to and from exchange surfaces.
What are the 5 types of blood vessels?
Arteries, Arterioles, Capillaries, Venules, and Veins.
What is the inner layer in a blood vessel called, and what does it do?
It is called the endothelium (tunica intima), and it provides a smooth passage for blood to flow through.
What is the middle layer in a blood vessel called, and what does it do?
The middle layer is called the tunica media, and it is made of smooth muscle which contracts, and it has elastic fibres, which recoils in order to withstand the high blood pressure.
What is the outer layer in a blood vessel called, and what does it do?
It is called the tunica adventitia, and it is the connective tissue, which is high in collagen.
What is the gap in the middle of the blood vessel called, and what does it do?
It is called the lumen, and it is the passage for the blood to flow through.
What is collagen?
Collagen is a key structural protein, which makes up 25-30% of the body’s protein content.
What makes blood flow in the thinner-walled veins?
Blood flows in the veins due to pressure from skeletal muscles.
Which chamber of the heart has the thickest wall and why?
The left ventricle has the thickest wall, because it needs to pump blood throughout the whole body.
What happens during cardiac diastole?
Blood flows into the atria, from the vena cava and pulmonary vein, with closed atrioventricular valves.
What happens during atrial systole?
The pressure increases in the blood-filled atria, pushing the atrioventricular valves open, and the blood flows into the ventricles. Then, the atria both contract, forcing all of the blood into the ventricles.
What happens during ventricular systole?
The ventricles contract, which forces the atrioventricular valves to close, and the semilunar valves to open, forcing blood into the pulmonary artery and aorta.
What is atherosclerosis?
Atherosclerosis is the process that causes arteries to become too narrow.
What is the 1st stage of atherosclerosis?
The endothelium becomes damaged and dysfunctional.
What is the 2nd stage of atherosclerosis?
Macrophages leave the blood vessel and move into the artery wall.
What is the 3rd stage of atherosclerosis?
Calcium salts and fibrous tissue builds up, resulting in a hard swelling called plaque and the inner wall of the artery.
What is the 4th stage of atherosclerosis?
The lumen becomes narrower due to the plaque, which can cause high blood pressure.
What is the 1st stage of thrombosis?
Platelets and damaged tissue release a protein called thromboplastin.
What is the 2nd stage of thrombosis?
The thromboplastin activates an enzyme which catalyses the conversion of prothrombin into an enzyme known as thrombin.
What is the 3rd stage of thrombosis?
Thrombin catalyses the conversion of fibrinogen into fibrin.
What is the 4th stage of thrombosis?
A mesh of fibrin forms, which traps more platelets and red blood cells, forming a blood clot.
What does it mean if a substance is non-polar?
It is hydrophobic, and doesn’t dissolve in water