Question

Describe the pathway that air takes beginning with our nose and ending in the bloodstream. Include brief descriptions of each “part” or “area” as the air passes through it.

Answer 1

The pathway -

1. Nose - It is an sensory organ which includes nostrils and nasal cavilty in which hairs and cilia are present to stop the dust and other foreign particles.

2. Pharynx - It is a common passage of food and air.It separates in two parts - trachea(Anteriorly) and esophagus (posteriorly).

3. Larynx - A hollow chamber made of 9 cartilages present in upper initial part of trachea.It is also called the voice box and prevents food from entering the trachea by closing the windpipe with the help of epiglottis.

4.Trachea - It is a 10 - 12 cm long , hollow and straight pipe which enters in media stenum of thoracic cavity.It separates in two parts at 5th thoracic vertebrae in bronchi.

5.Bronchi - These bronchi enter into lungs and further divides in seconday and tertiary bronchi.

6.Bronchioles - The tertiary bronchi further branches into broonchioles which are fine tubules and at the end make alveoli.

7.Alveoli - These are functional units of lungs.Around 300 million alveoli are found in both lungs combindly. The blood capillaries surround these alveoli where gaseous exchange takes place.

Thus air enters in blood stream .