It is a long, thick tube about 2 1⁄2 inches in
diameter and about 5 feet long.
It is located just inferior to the stomach
and wraps around the superior and lateral
border of the small intestine.
It absorbs water and vitamins while
converting digested food into Solid waste
products and exit the body through the
1. Ingestion of food Trachea or windpipe
2. Secretion of fluids and digestive enzymes
3. Mixing and movement of food and wastes It is a 5-inch long tube made of C-shaped
through the body hyaline cartilage rings lined with pseudo-
4. Digestion of food into smaller pieces stratified ciliated columnar epithelium.
5. Absorption of nutrients It connects the larynx to the bronchi and
6. Excretion of wastes allows air to pass through the neck and
into the thorax.
RESPIRATORY SYSTEM The rings of cartilage making up the
trachea allow it to remain open to air at all
It allows us to take in vital oxygen and
expel carbon dioxide in a process we call
breathing. It is used to provide a clear airway for air
to enter and exit the lungs.
It consists mainly of the trachea, the
diaphragm and the lungs. Diaphragm
The nose and nasal cavity form the main
external opening for the respiratory system It is the primary muscle used in the
and are the first section of the body’s process of inspiration, or inhalation.
airway—the respiratory tract through It is a dome-shaped sheet of muscle that is
which air moves. inserted into the lower ribs. Lying at the
Red blood cells collect the oxygen from base of the thorax (chest), it separates the
the lungs and carry it to the parts of the abdominal cavity from the thoracic cavity.
body where it is needed. The red blood The nerve that controls the diaphragm is
cells collect the carbon dioxide and the phrenic nerve, which originates at
transport it back to the lungs, where it vertebral level C3-C5.
leaves the body when we exhale.
A decrease in oxygen is known as Lungs
hypoxia and a complete lack of oxygen is These are a pair of large, spongy organs
known as anoxia. found in the thorax lateral to the heart and
superior to the diaphragm.
Each lung is surrounded by a pleural
membrane that provides the lung with
space to expand as well as a negative
pressure space relative to the body’s