Resipiration and Gas exchange

Question 1

Word equation for anaerobic respiration in plants and in animals

Answer 1

Glucose —> ethanol + carbon dioxide + energy

Question 2

Describe role of intercostal muscles and the diaphragm during inhalation

Answer 2

• the diaphragm contracts and flattens
• The intercostal muscles contract to pull the ribs up and out
• Increased volume in thorax
• Leading to a decrease in air pressure inside the lung relative to the outside the body
• Air is drawn in

Question 3

Describe the role of the intercostal muscles and the diaphragm in exhalation

Answer 3

• Diaphragm relaxes and becomes a domed shape
• The external set of intercostal muscles relax so the ribs drop down and in
• This decreases the volume of the thorax
• Leading to an increase in air pressure inside the lungs relative to outside the body
• Air is forced out

Question 4

The biological consequences of smoking in relation to the lungs and the circulatory system, including coronary heart disease

Answer 4

• Nicotine narrows blood vessels which leads to an increase in blood pressure
• Tar increased the chance of getting cancer. Chronic bronchitis is caused by tar which causes more mucus being produced. Mucus will block the bronchioles

Question 5

Explain how coronary heart disease can cause death

Answer 5

The coronary arteries supply blood to the heart become blocked, due to build-up of fat. This means less blood is carries heart and less oxygenated blood eventually lead to death of muscle cell.