The respiratory system 
Respiration.
*The respiratory system consists of tubes that filter incoming air and transport it into the microscopic alveoli where gases are exchanged the entire process of exchanging gases between the atmosphere and body cells is called respiration and consists of the following: ventilation, gas exchange between blood and lungs, gas transport in the bloodstream, gas exchange between the blood and body cells, and cellular respiration
*The organs of the respiratory tract can be divided into two groups: the upper respiratory tract (nose, nasal cavity, sinuses, and pharynx), and the lower respiratory tract (larynx, trachea, bronchial tree, and lungs). *The pharynx is a common passageway for air and food. The pharynx aids in producing sounds for speech. *The larynx is an enlargement in the airway superior to the trachea and inferior to the pharynx. It helps keep particles from entering the trachea and also houses the vocal cords. The larynx is composed of a framework of muscles and cartilage bound by elastic tissue. Inside the larynx, two pairs of folds of muscle and connective tissue covered with mucous membrane The upper pair is the false vocal cords. The lower pair is the true vocal cords During swallowing, the false 6 cords and epiglottis close off the glottis * The trachea extends downward anterior to the esophagus and into the thoracic cavity, where it splits into right and left bronchi. The inner wall of the trachea is lined with ciliated mucous membrane with many goblet cells that serve to trap incoming particles. *The bronchial tree consists of branched tubes leading from the trachea to the alveoli. The bronchial tree begins with the two primary bronchi, each leading to a lung. The branches (Figs. 16.8-16.9) of the bronchial tree from the trachea are right and left primary bronchi; these further subdivide until bronchioles give rise to alveolar ducts which terminate in Avioli .It
*The respiratory system consists of tubes that filter incoming air and transport it into the microscopic alveoli where gases are exchanged the entire process of exchanging gases between the atmosphere and body cells is called respiration and consists of the following: ventilation, gas exchange between blood and lungs, gas transport in the bloodstream, gas exchange between the blood and body cells, and cellular respiration
*The organs of the respiratory tract can be divided into two groups: the upper respiratory tract (nose, nasal cavity, sinuses, and pharynx), and the lower respiratory tract (larynx, trachea, bronchial tree, and lungs). *The pharynx is a common passageway for air and food. The pharynx aids in producing sounds for speech. *The larynx is an enlargement in the airway superior to the trachea and inferior to the pharynx. It helps keep particles from entering the trachea and also houses the vocal cords. The larynx is composed of a framework of muscles and cartilage bound by elastic tissue. Inside the larynx, two pairs of folds of muscle and connective tissue covered with mucous membrane The upper pair is the false vocal cords. The lower pair is the true vocal cords During swallowing, the false 6 cords and epiglottis close off the glottis * The trachea extends downward anterior to the esophagus and into the thoracic cavity, where it splits into right and left bronchi. The inner wall of the trachea is lined with ciliated mucous membrane with many goblet cells that serve to trap incoming particles. *The bronchial tree consists of branched tubes leading from the trachea to the alveoli. The bronchial tree begins with the two primary bronchi, each leading to a lung. The branches (Figs. 16.8-16.9) of the bronchial tree from the trachea are right and left primary bronchi; these further subdivide until bronchioles give rise to alveolar ducts which terminate in Avioli .It