GENERAL HISTOLOGY

Detailed explanation-1: -When you breathe in: Air enters your body through your nose or mouth. Air then travels down the throat through the larynx and trachea. Air goes into the lungs through tubes called main-stem bronchi.

Detailed explanation-2: -The lungs and respiratory system allow us to breathe. They bring oxygen into our bodies (called inspiration, or inhalation) and send carbon dioxide out (called expiration, or exhalation). This exchange of oxygen and carbon dioxide is called respiration.

Detailed explanation-3: -The NASAL CAVITY (nose) is the best entrance for outside air into your respiratory system. The hairs that line the inside wall are part of the air-cleansing system. Air can also enters through your ORAL CAVITY (mouth), especially if you have a mouth-breathing habit or your nasal passages may be temporarily blocked.

Detailed explanation-4: -When you breathe in (inhale), air containing oxygen enters your windpipe, passes through the bronchi and eventually reaches the air sacs. These air sacs, called alveoli, are responsible for gas exchange.

Detailed explanation-5: -The nasal cavities are chambers of the internal nose. In front, the nostrils, or nares, create openings to the outside world. Air is inhaled through the nostrils and warmed as it moves further into the nasal cavities. Scroll-shaped bones, the nasal conchae, protrude and form spaces through which the air passes.