4.4 Circulation

Question 1

Compare and contrast the circulatory system of an insect with the structure of the circulatory system of the mammal

Answer 1

Both have hearts
Both have valves
Mammals have closed system
Mammaks have double circulatory system and insects have a single
Mammal have separate pulmonary circulation system unlike insects

Question 2

Describe how atherosclerosis develops in the coronary arteries

Answer 2

Damage to endothelium by high blood pressure/ smoking
Inflammatory response and arrival of macrophages
Deposits of cholesterol
Formation of atheroma

Question 3

Compare and contrast the structure of the frog heart with the structure of a mammalian heart

Answer 3

Both have 2 atria
Both have AV valves
Heart divided into atria and ventricles

Frog has one ventricle only
Frog only has 3 chambers
Frog has no artery valves

Question 4

How double circulatory system ensures a higher hydrostatic pressure than a single circulatory system

Answer 4

Blood lapses through the heart twice

Question 5

Explain how the weakening of cardiac muscle could affect a person

Answer 5

Heart cannot pump as well
Less oxygen delivered to tissues
Fatigue, breathlessness, etc

Question 6

Explain why change in concentration of amino acids results in weakening of cardiac muscle

Answer 6

Less proteins made
Proteins involved in heart muscle so structure will be weaker
Proteins may affect heart function

Question 7

Describe the function of neutrophil in defence

Answer 7

Phagocytosis
Digest pathogens

Question 8

Describe how three factors, other than high blood pressure can increase risk of atherosclerosis

Answer 8

Smoking damages artery lining
Type 2 diabetes increases blood pressure
High cholesterol forms atheroma in arteries
Lack of exercise causing obesity
Inherited alleles from parents who had CVD