internal transport

Question 1

structure of heart

Answer 1

1.divided into 4 chambers
2.two upper chambers called atria, receive blood from lungs or body and transport it to the ventricles
3.two lower chambers called ventricles, pump blood out of the heart and all around the body
4.chambers on the left hand side and right hand side are completely separated by septum

Question 2

systemic circulation

Answer 2

1.left atrium receives blood from the pulmonary vein, which carries blood from the lungs
2.blood flows to the left ventricle through the bicuspid valve
3.the blood in the left ventricle is pumped into the aorta, which takes the blood around the body

Question 3

pulmonary circulation

Answer 3

1.the right atrium receives blood from the rest of the body, arriving through the vena cava
2.blood flows to the right ventricle through the tricuspid valve
3.the right ventricle pumps blood into the pulmonary artery which carries it to the lungs

Question 4

effect of exercise on heart rate

Answer 4

1.heart rate increases so more blood reaches the muscles, more aerobic respiration and energy release, removal of excess co2 and lactic acid
2.during exercise muscles respire more releasing more carbon dioxide which dissolves in the plasma lowering the ph
3.chemoreceptors in cartoid artery and the aorta detect the acidic ph and send impulses to cardiovascular center in the brain medulla which sends impulse to pacemaker of the heart to increase the heart rat3

Question 5

coronary heart disease

Answer 5

fats and glycerol build up in atheroma on walls of coronary artery blocking them, less blood reaches the heart muscle cells, so less o2, and glucose, less aerobic respiration resulting in cell death causing heart attack

Question 6

causes of coronary heart disease

Answer 6

1.smoking
2.diet
3.stress
4.lack of exercise

Question 7

treatment of coronary heart disease

Answer 7

1.stents
2.heart transplant
3.artificial heart
4.statins
5.plant stanol esters
6.beta blockers

Question 8

stents

Answer 8

widen the narrowed or blocked coronary artery, allowing blood to flow through them

Question 9

heart transplant

Answer 9

surgical transplant performed on patients with severe heart failure

Question 10

advantages of heart transplant

Answer 10

lifesaving

Question 11

disadvantages of heart transplant

Answer 11

1.few donors available
2.long recovery time
3.expensive

Question 12

artificial heart

Answer 12

synthetic device made of plastic and some metal alloys, their purpose is to keep people alive while waiting for suitable donor

Question 13

statins

Answer 13

chemicals that lower blood cholesterol, they inhibit an enzyme that is involved in the synthesis of cholesterol

Question 14

plant stanol esters

Answer 14

lowers blood cholesterol levels

Question 15

beta blockers

Answer 15

class of drugs, used to protect against second heart attack, they block receptors of adrenaline in various parts

Question 16

causes of hypertension

Answer 16

genetic factors
high salt content
lack of exercise
obesity
smoking
kidney disease

Question 17

features of arteries

Answer 17

1.very strong walls to withstand high pressure
2.have elastic tissue in their walls that can stretch and recoil
3.narrow lumen to maintain high pressure
4.walls of the arteries have muscles that control size of lumen

Question 18

features of veins

Answer 18

1.lumen is wider in vein than in arteries to decreases resistance to blood flow
2.have valves in them to stop the blood flowing backwards
3.thin walls to be easily squeezed by skeletal muscles

Question 19

adaption of capillary

Answer 19

thin walls for short diffusion distance
wall has pores for rapid exchange

Question 20

function of capillary

Answer 20

1.allows transport of o2, glucose, amino acids, minerals, vitamins from blood to cells
2.allows co2 and urea out of cells to blood

Question 21

plasma:

Answer 21

yellow part of the blood

Question 22

function of plasma

Answer 22

transports water, dissolved nutrients, wastes, hormones, and co2

Question 23

function of red blood cell

Answer 23

transports oxygen

Question 24

adaption of red blood cell

Answer 24

biconcave to increase surface area to increase rate of diffusion
no nucleus to provide more space for haemoglobin