3. Brief insight into the
Anatomical & Physiological
Characteristics of the
Trachea
4. The trachea is a flexible pipe which travels from
the throat down into the thorax. It is supported
by rings of a flexible but strong material called
cartilage.
It
prevents
the
trachea
from
collapsing as inspired and expired air move
through it. The cartilage rings also allow for
continue breathing when the neck is bent. The
inside of the trachea is covered by millions of
microscopic hairs called cilia.
5. The cilia are covered with a layer of liquid called
mucus. Very fine dust particles and microbes
get trapped in the mucus and cilia. Although the
cilia are attached at one end, each one is able to
move (beat). As the cilia beat they tend to push
the dust-containing mucus toward the nose and
the mouth. In this way the lungs are kept free of
most of the dust and microbes inhaled.
7. The trachea develops caudal to the larynx.
The endodermal lining of the laryngotracheal
tube differentiates into the epithelium and
glands of the trachea and the pulmonary
epihelium.
8. The epithelium develops from the endoderm
and the tracheal cartilage and muscles develop
from splanchnic mesoderm.
Early in development, the trachea bifurcates
into the left and right bronchi.
9.
10. CLINICAL CORRELATES
Tracheoesophageal fistula is an abnormal communication
between the trachea and esophagus that results from improper
division of foregut by the tracheoesophageal septum. It is
generally
associated
polyhydramnios.
with
esophageal
atresia
and
11. Clinical features include excessive accumulation of saliva or
mucus in the nose and mouth; episodes of gagging and
cyanosis after swallowing milk; abdominal distention after
crying; and reflux of gastric contents into lungs, causing
pneumonitis.
Diagnostic features include inability to pass a catheter into the
stomach and radiographs demonstrating air in the infant's
stomach. There are five different anatomical types of
esophagus and trachea malformations as follows:
12. Esophageal atresia with a tracheoesophageal fistula at the
distal one-third end of the trachea. This is the most common
type, occurring in 82% of cases. The anteroposterior (AP)
radiograph (the image on the next slide) of this malformation
shows an enteric tube (arrow) coiled in the upper esophageal
pouch.
The
air
in
tracheoesophageal fistula.
the
bowel
indicates
a
distal
13. Esophageal atresia with a tracheoesophageal fistula at the distal one-third end of the
trachea
15. H-type tracheoesophageal fistula only. This malformation
occurs in 6% of cases. The barium swallow radiograph (in
the image below) shows a normal esophagus (E), but dye
has spilled into the trachea (T) through the fistula and
outlines the upper trachea and larynx.
16. Esophageal atresia with a tracheoesophageal fistula at
both proximal and distal ends. This malformation occurs in
2% of cases.
17. Esophageal atresia with a tracheoesophageal fistula at the
proximal end. This malformation occurs in 1% of cases
