Chapter 7: Respiration in humans ( how do humans breathe)

Question 1

How are the ribs attached to the body?

Answer 1

dorsally to the vertebral column, ventrally to the sternum

Question 2

What is the breathing mechanism of the diaphragm and the ribcage? ( when breathing in cause exhalation is the opposite)

Answer 2

1. When diaphragm muscles contract, the diaphragm will flatten
2. External intercostal muscles contract while internal intercostal muscles relax
   - ribs and sternum moves up and outwards
3. volume of the thoracic cavity increases, lungs expand
   - pressure inside the lungs decrease
4. atmospheric pressure is higher than pressure within the lungs
   - air moves into lungs

Question 3

What are the 3 major toxic components in tobacco smoke?

Answer 3

nicotine,tar,carbon monoxide

Question 4

What are the harmful effects of nicotine? (adrenaline and clots)

Answer 4

It stimulates the production of adrenaline, increasing heart rate and blood pressure.

It increases the risk of blood clots in arteries , causing them to narrow, increasing risk of coronary heart disease.

Question 5

What are the harmful effects of tar? (cell division and bronchitis)

Answer 5

It causes uncontrolled cell division, increasing the risk of lung cancer.

It paralyses cilia lining the air passages, causing dust particles to get trapped in mucus, increasing the risk of chronic bronchitis and emphysema.

Question 6

What are the harmful effects of carbon monoxide? (haemoglobin and fatty deposits)

Answer 6

It would bind permanently with the haemoglobin to form carboxyhaemoglobin, reducing the efficiency of oxygen transport.

It increases the risk of fatty deposits n the inner arterial wall, increasing the risk of coronary heart disease.

Question 7

What is chronic bronchitis?

Answer 7

There would be inflaming of the lining of air passages, for excessive mucus to be secreted.
It also paralyses cilia, so it cannot sweep away dust particles trapped in mucus. ( blocking air passageways)

Question 8

What is emphysema?

Answer 8

It is persistent and violent coughing due to bronchitis.
The partition walls between alveoli will break down, decreasing surface area for gas exchange.
- lungs lose elasticity and become deflated
- difficulty breathing, causing wheezing and breathlessness