Small Cell Lung Cancer
Small
Cell Lung Cancer:
The paired lungs develop from lung buds in
the human embryo during a period of rapid cell division.
The main type of cell in the lungs is called"epithelial", meaning a lining
cell. Mucous is formed by
"adeno" cells which fold into glands. Another type of cell, called
the"type II" cell, secretes
"surfactant" which provides the stiffness for lung tissue. All of these
cells divide quickly during
womb life, infancy and puberty, but growth slows dramatically by
adulthood. In adults, the cells
only divide to replace ones lost to injury or old age. Air breathed in
passes though the throat into
the larynx, where the vocal cords can form sounds. Below the larynx is the
trachea, a tube ringed
with cartilage which helps keep it from collapsing. The trachea splits
("bifurcates") in an upside-
down "Y" with the arms of the "Y" going into each lung. The part of the
trachea that actually
enters each lung is called the"mainstem bronchus" ; there is a right and a
left one to correspond
with each lung. The area where the mainstem bronchi enter is called the
"hilum" of each lung, the
main blood vessels also enter at the hilum. The main bronchi branch out
into smaller"lobar"
and"segmental" bronchi to carry the air into the lungs. The right lung is
made up of 3 lobes, and
the left lung of 2 lobes. Each lobe is made up of smaller segments. The
air breathed into the lungs
ultimately gets to the tiny air sacs, called"alveoli", which provides the
surface for the oxygen in air
to mix with the blood..
Non-Small
Cell Lung Cancer:
Non-small
cell lung cancer is a disease in which malignant (cancer) cells form in
the tissues of the
lung. The lungs are a pair of cone-shaped breathing organs that are found
within the chest. The
lungs bring oxygen into the body and take out carbon dioxide, which is a
waste product of the
body's cells . Each lung has sections called lobes . The left lung has 2
lobes. The right lung, which
is slightly larger, has 3 lobes. A thin membrane called the pleura
surrounds the lungs. Two tubes
called bronchi lead from the trachea (windpipe) to the right and left
lungs. The bronchi are
sometimes also involved in lung cancer . Tiny air sacs called alveoli and
small tubes called
bronchioles make up the inside of the lungs..
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