Respiratory tract

1. Respiratory tract
In humans the respiratory tract is the part of the anatomy that has to do with the process of respiration.
The respiratory tract is divided into 3 segments:
Upperrespiratory tract: nose and nasal passages, paranasal sinuses, and throat or pharynx
Respiratory airways: voice box or larynx, trachea, bronchi, and bronchioles
Lungs: respiratory bronchioles, alveolarducts, alveolar sacs, and alveoli
2. Nose
Is the protruding part of the face that bears the nostrils. The shape of the nose is determined by the ethmoid bone and the nasal septum, which consistsmostly of cartilage and which separates the nostrils. On average the nose of a male is larger than that of a female.
3. Larynx
Commonly called the voice box, is an organ in the neck of mammals(including humans) and many other vertebrates involved in breathing, sound production, and protecting the trachea against food aspiration.

4. Pharynx
Is the part of the throat situated immediatelyposterior to (behind) the mouth and nasal cavity, the human pharynx is conventionally divided into three sections: the nasopharynx (epipharynx), the oropharynx (mesopharynx), and the laryngopharynx(hypopharynx). The pharynx is part of the digestive system and also the respiratory system; it is also important in vocalization.

5. Nasopharynx , Oropharynx and Laryngopharynx
• Nasopharynx
Is the mostimportant part in digestive and the respiratory system. The nasopharynx is the most cephalad portion of the pharynx. It extends from the base of the skull to the upper surface of the soft palate.
•Oropharynx
Lies behind the oral cavity, extending from the uvula to the level of the hyoid bone
• Laryngopharynx
Is the caudal part of the pharynx; it is the part of the throat that connects to theesophagus.
6. Trachea
Is a tube that connects the pharynx or larynx to the lungs, allowing the passage of air. It is lined with pseudostratified ciliated columnar epithelium cells with goblet...