Explain the human respiratory system ( …

Larynx – “Adam‟s apple” 

Glottis – Aperture in laryngopharynx which opens into trachea. 

Epiglottis – A cartilaginous flap present at the anterior margin of glottis. It projects into the pharynx opposite the uvula. During swallowing, larynx moves upward to close the glottis to check the entry of food into it. 

Trachea/ Windpipe – thin walled tube extends downward through the neck. 

Bronchi – Trachea divides into two tubes called bronchi in the middle of the thorax. 

Bronchioles – Bronchi divide and re-divide into tertiary bronchi which divide into alveolar ducts which enter into alveolar sacs. 

Lungs – Human respiratory organ, located in the thoracic cavity.  

Alveolar sac – In the lung, each alveolar duct opens into a blind chamber, the alveolar sac which appears like a small bunch of grapes. 

Alveoli / Air sacs – The central passage of each alveolar sac gives off several small pouches on all sides, the alveoli or air sacs. 

Alveolar wall – is very thin (0.0001 mm) wall composed of simple moist, non-ciliated, squamous epithelium which easily recoil and expand during breathing.