Circulatory system

Question 1

What dietary nutrient can contribute to the development of fatty plaques in the walls of the arteries

Answer 1

• saturated fats

Question 2

stages of the development of atherosclerosis in the arteries

Answer 2

• high levels of cholesterol in blood plasma
• macrophages become foam cells and sink into artery walls
• this causes formation of plaques
  -reduces blood flow because the inside of the artery becomes narrow

Question 3

Why is the heart called an organ

Answer 3

• made up of tissues
• carries out a particular function of the body

Question 4

gas exchange in the alveoli

Answer 4

• occurs at the alveoli in the lungs
• alveoli are surrounded by capillaries so oxygen and C02 can diffuse
• high conc of CO2 in blood and low in alveoli so it diffuses into alveoli
• oxygen and C02 combine with haemoglobin
• alveoli walls are thin so CO2 and oxygen can easily pass through