biology heart mistakes

Question 1

explain why av valves need to close

Answer 1

ventricle needs to contract and force blood into the aorta/ pulmonary artery/ artery, there for valves need to close to prevent back flow of blood back into atria during contraction

Question 2

why are there (blood) pressure differences within the left atrium and left ventricle.

Answer 2

1) differences due to when systole takes place. ( atrial systole takes place before ventricular systole so pressure increases in left atrium first)

1) yet when atrial systole takes place it is lower in pressure that when ventricular systole would take place as ATRIA HAS A THINER CARDIAC MUSCLE WALL AS IT HAS A SHORTER DISTANCE TO TRANSPORT BLOOD TO. gravity aids flow of blood form atria to ventricle.

ventricles have a thicker cardiac muscle as has to transport blood all around body.

Question 3

what is alveolus and aveoli

Answer 3

alveolus is singular aveoli is plural

Question 4

exam question:
During the development of the mammalian heart, there is a hole between the left ventricle and the right ventricle.
This hole usually becomes sealed before the mammal is born. If it is not sealed, the mammal will become easily tired due to a lack of energy.
Explain why a mammal born with a hole between the two ventricles will have these symptoms.

Answer 4

• less oxygen available for aerobic respiration

deoxygenated blood will mix with oxygenated blood

this will reduce oxygen concentration of blood that is circulating the body

due to some deoxygenated blood not leaving to go to lungs, so will go to respiring tissue with require o2 blood

Question 5

exam question: describe the role of LDL in the development of am atheroma

Answer 5

LDL/ low density lipoproteins carry cholesterol in the blood

cholesterol is deposited to form an atheroma

in the endothelium of the artery

Question 6

exam question:
explain how atheresclorosis can result In damed to the heart muscle

atherosclerosis

Answer 6

narrowing of the lumen of the at the coronary arteries

this reduced blood flow to the cardiac (heart) muscle

this reduces aerobic respiration

more anaerobic respiration which can lead to boils up of Lactic acid

Question 7

what do statins do?

Answer 7

statins lower cholesterol in blood however they do not break down blood clots

Question 8

why is a blood clot in an artery at lung detrimental

Answer 8

reduced blood flow to lung

reduced gas exchange

less red blood cells can be oxygenated

Question 9

exam question:
Q7.
Thrombophilia is a condition that increases the risk of blood clots forming.
This condition increases the risk of venous thromboembolism (VTE), a condition where a blood clot forms in a vein. Thrombophilia due to the production of overactive factor V can be inherited.
Factor V is involved in the conversion of prothrombin to thrombin. (i) Describe the role of thrombin in blood clotting.

(ii) Explain why a mutation in the gene coding for the protein factor V may increase the risk of VTE.
(3)

Answer 9

mutation in the gene changes the sequence of amino acids in the factor v molecule

overactive factor v will increase production of thrombin in blood

this will increase blood clotting