MASS TRANSPORT : BLOOD VESSELS

Question 1

important blood vessels entering and leaving

Answer 1

1. heart = attatched to venacava, aorta, pulmonary artery and pulmonary vein.
2. lungs = pulmonary artery and pulmonary vein
3. kidneys = rena; artery and renal vein.

Question 2

blood vessels

Answer 2

arteries, arterioles, capillaries and veins
- arteries = carry blood away from the heart
- veins = carries blood in the heart
- capillaries = connects the arterioles to the veins.
- arterioles = smaller than arteries and connected to capillaries

Question 3

lumen

Answer 3

the hole in the middle from where bllod flows through

Question 4

arteries

Answer 4

arteries trasnports blood quickly at a high pressure.

Question 5

adaptation of arteries

Answer 5

MEW
M - muscle walls are thick so that constriction and dilation can occur to maintain the volume of the blood.
E - elasticity in the walls of arteries so that walls can stretch and recoil in response to the heart beat.
W - walls are thicker to prevent the burstin of arteries because of high blood pressure.

Question 6

three layers of artery

Answer 6

1. tunica interna = made up of smooth cells to minimise the friction during the transport of blood.
2. tunica media - smooth muscles, elastin and collagen
3. tunica externa = elastic fibre and collagen fibre.

Question 7

arterioles

Answer 7

as blood goes from artery to arterioles, the cross sectional area increases , pressure lowers and speed of blood slows down as well.

Question 8

which is the largest artery

Answer 8

aorta

Question 9

veins -

Answer 9

• veins contain valves which prevents the backflow of blood.
• veins have a relative,y thin wall because the blood pressure is low.
• the thinness in veins means that the vessels are easily flattened which helps the flow of blood upto the heart.

Question 10

capillaries

Answer 10

tiniest blood vessels formed from the brancing of arterioles.

Question 11

function of capillaries

Answer 11

• to transport the blood as close as possible to all cells inorder to allow for rapid transfer of substances between cells and blood.

Question 12

adaptation of capillaries

Answer 12

• really thin. made up of single layer of endothelial cells . very short diffusion distance between blood and cells which maximises the rate of diffusion.
• red blood cells can only just fit through the capillaries and squashed against the walls which slows down the movement and maximises rate of diffusion.
• capillaries are in large number and have a highly branched structure providing a larger surface area.

Question 13

important blood vessels

Answer 13

pulmonary artery and aorta = carries blood away from the heart
pulmonary vein and venacava = carries blood towards the heart
renal artery and renal vein

Question 14

tissue fluid

Answer 14

• liquid surrounding the cells
• controls exchange of substances
• formed from blood plasma.

Question 15

what does tissue fluid consists

Answer 15

water, glucose, amino acid, oxygen etc.

Question 16

tissue fluid mechanism

Answer 16

• capillaries have small gaps so that the liquid and molecules can pass out.
• as the blood flows into the capillaries from the arterioles, because of the small diameter there is a hugh hydrostatic pressure and small molecules like glucose and amino acids are filtered out. this process is called ultrafiltration.
• small molecules are forced out however larger molecules such as proteins and RBCs stay in the capillaries and reduces the water potential.
• at the venous end of the capillaries the hydrostatic pressure and the the water potential is low because of the loss of the water.
• water is re absorbed into capillaries by osmosis.
• however not all liquids are absorbed by osmosis. so the remaining tissue fluids are absorbed by the lymphatic system and drained to the bloodstream near the heart.