Each divides into 2 to 11 alveolar ducts.
Small fingers (extensions) of the main bronchial tubes that bring air into
your lungs. This allows for greater air distribution. Theses divide into
alveoli ducts, which lead to the alveoli.ALVEOLI (AIR SACS)
Only a thin, single-celled membrane which separates air from blood.
Your lungs contain over 300,000,000 alveoli (or air sacs) that allow over
2,500 gallons of air to pass into your blood stream each day.
There is over 750 sq. ft. of pulmonary capillary surface area for the
exchange of oxygen.PHARYNX
The pharynx is a muscular tube that connects the nasal cavity to the larynx. It
also connects the mouth with the esophagus. It extends from the base of your
skull to your sixth cervical vertebra. There it divides into anterior (behind),
which becomes the esophagus, and inferior (in front), which becomes the
larynx.
LARYNX
The larynx consists of nine cartilages, bound together by an elastic membrane
and controlled by muscles. It connects with the epiglottis, hyoid bone, thyroid
cartilage, vocal cords and cricoid cartilage at one end, and the trachea at the
other.
TRACHEA (WINDPIPE)
Your trachea is a 4.5-inch-long cartilaginous tube. The trachea bridges the
larynx to the primary or main bronchi. It extends from the sixth cervical to
the fifth dorsal (thoracic) vertebra. At this point it divides into two main
bronchi, one leading to each lung. The mucosa is made of ciliated epithelia
that sweep mucus, trapped dust and pathogens upward.