Question

Follow a molecule of oxygen thru the upper and lower respiratory system to the respiratory membrane?

Answer 1

Oxygen is very important for survival of body tissues which is provided by atmosphere to the human beings.

Air which contains various gases such as oxygen, nitrogen dioxide, water vapours etc.

Air enter nose via two nasal openings called as nostrils --> it will then travel through nasal cavity --> reaches posterior nasal choana --> and then enter into the nasopharynx -->further to the larynx --> from larynx it further enters into the windpipe that is also known as trachea --> trachea is a cartilaginous tube like structure which further divides into two tubes known as bronchi --> oxygen molecule will enter either left or right bronchi --> will further pass to the secondary bronchi then tertiary bronchi then terminal bronchioles and finally to the respiratory bronchioles --> now, the oxygen molecules will enter the alveolar duct --> finally reaching alveolar sac --> alveolar epithelium, at this level along with epithelium pulmonary capillaries form respiratory membrane where gaseous exchange takes place --> oxygen molecule will diffuse along this membrane and will be taken up by red blood cells which will carry this oxygen molecule to the left atrium of the heart via the pulmonary veins. From left atrium , this molecule will be pumped to left ventricle and left ventricle will further pump this molecule to the aorta which will carry this oxygen molecule to the tissue site.