Which of the following statements are correct regarding respiration from given statement and choose correct option ?
(i) Lungs are situated in the thoracic chamber which is anatomically an air-tight chamber.
(ii) The thoracic chamber is formed dorsally by the vertebral column, ventrally by the sternum, laterally by the ribs and on the lower side by the dome-shaped diaphragm.
(iii) The movement of air into and out of the lungs is carried out by creating a pressure gradient between the blood and the atmosphere.
(iv) Inspiration can occur if the pressure within the lungs (intra-pulmonary pressure) is less than the atmospheric pressure.
(v) Expiration takes place when the intra- pulmonary pressure is higher than the atmospheric pressure.
(vi) The diaphragm and a specialised set of muscles- external and internal intercostals between the ribs, help in generation of such gradients.
(vii) We have the ability to increase the strength of inspiration and expiration with the help of additional muscles in the abdomen.
(viii) On an average, a healthy human breathes 22-26 times/minute.
