(a)(i) Briefly explain the term respiration.
(ii) Name the two types of respiration and write a balanced equation to summarize each of them.
(b) Outline the mechanisms involved in: (i) inhalation; (ii) exhalation in human beings
Explanation
(a)(1) Respiration: This is a process in living organisms cells involving enzyme-catalyzed chemical reactions; in which food substances/glucose are broken down within cells, to release energy, in the presence or absence of oxygen.
(ii) Aerobic respiration;- C(_6)H(_1)(_2)O(_6)+6O(_2) →6H(_2)O + 6CO(_2) + Energy
Anaerobic respiration: C(_6)H(_1)(_2)O(_6)→2C(_2)H(_5)OH+2CO(_)2 + Energy
(b)(i) During Inhalation:
(1) External intercostal muscles contract
(2) Internal intercostal muscles relax
(3) Ribs move up and outwards
(4) Diaphragm contracts/flattens
(5) Volume of thorax cavity increases
(6)Air pressure decreases
(7)Air rushes into the lungs from the atmosphere.
(ii) During Exhalation:
– External intercostal muscles relax
– Internal intercostal muscles contract
– Ribs move down and inwards
– Diaphragm relaxes/becomes dome-shaped
-Volume of thorax cavity decreases
-Air pressure increases
– Air is forced out of lungs into the atmosphere.