Question 1:
State the function of the spiracle in the breathing mechanism of insects.
Answer:
Spiracles are air pores that connect the respiratory structure of insects with the external environment.
State the function of the spiracle in the breathing mechanism of insects.
Answer:
Spiracles are air pores that connect the respiratory structure of insects with the external environment.
Question 2:
How do abdominal muscles help insects to breathe?
Answer:
• During inhalation, the abdominal muscles relax and the spiracle valves open. This reduces the internal pressure of the trachea causing air to be drawn into the trachea through the spiracle.
• During exhalation, the abdominal muscles contract. This increases the internal pressure of the trachea forcing air out through the spiracle.
How do abdominal muscles help insects to breathe?
Answer:
• During inhalation, the abdominal muscles relax and the spiracle valves open. This reduces the internal pressure of the trachea causing air to be drawn into the trachea through the spiracle.
• During exhalation, the abdominal muscles contract. This increases the internal pressure of the trachea forcing air out through the spiracle.
Question 3:
State the two differences between the respiratory mechanisms of fish and humans.
Answer:
• Fishes have filaments and gills as their respiratory structures while humans have alveoli.
• The respiratory tract/opening of fish is the mouth and operculum while in humans, it is the nose.
State the two differences between the respiratory mechanisms of fish and humans.
Answer:
• Fishes have filaments and gills as their respiratory structures while humans have alveoli.
• The respiratory tract/opening of fish is the mouth and operculum while in humans, it is the nose.
Question 4:
Explain the mechanism of inhalation in humans.
Answer:
• The external intercostal muscles contract, the internal intercostal muscles relax.
• The action causes the rib cage to move upwards and outwards.
• At the same time, the diaphragm muscles contract and the diaphragm is lowered and flattened.
• Both movements cause the volume of the thoracic cavity to increase and its pressure to decrease.
• The higher atmospheric pressure outside forces air into the lungs.
Explain the mechanism of inhalation in humans.
Answer:
• The external intercostal muscles contract, the internal intercostal muscles relax.
• The action causes the rib cage to move upwards and outwards.
• At the same time, the diaphragm muscles contract and the diaphragm is lowered and flattened.
• Both movements cause the volume of the thoracic cavity to increase and its pressure to decrease.
• The higher atmospheric pressure outside forces air into the lungs.