Research Results For 'Bronchus'

BRONCHI

The bronchi are the tubes which carry air from the trachea to the inner recesses of the lungs, where it can transfer oxygen to the blood in the alveoli. Two main bronchi, the right and left bronchus, branch off of the low end of the trachea in what is called the tracheal bifurcation. One bronchus extends into each of the right and left lung. The bronchi continue to divide into smaller passageways, called bronchioles, forming a tree- like network of branches which extends throughout the spongy lung tissue. The exterior of the bronchi are composed of elastic, cartilaginous fibres and feature annular reinforcements of smooth muscle tissue. The bronchi are able to expand during inspiration, to allow the lungs to expand, and contract during expiration as air is exhaled.
Research Bronchi

BRONCHUS

The bronchus is a pipe connecting the trachea to the lung.
Research Bronchus

OESOPHAGUS

The oesophagus is the region of the alimentary canal following the pharynx. The walls of the
oesophagus are muscular and force food along by contractions. The oesophagus is composed of a thick muscle wall which is voluntary (striped) muscle in the upper part, and involuntary (smooth) muscle in the lower part. The oesophagus ends byjoining the cardiac orifice of the stomach a little less than four cm below the diaphragm. It therefore has three parts. The cervical portion in the lower part of the neck lies immediately behind the trachea with lobes of the thyroid on either side. The thoracic portion lies, in the upper part, close to the back of the trachea in front of the vertebral column. In the lower part the oesophagus passes a little to the left and is crossed by the left bronchus, later .lying immediately behind the pericardium until it pierces the diaphragm.

Except during the passage of food, the oesophagus is flattened like a muscle strap but can distend to 25 mm in diameter. With the exception of the pylorus it is the narrowest portion of the alimentary tract and the oesophagus itself has three constrictions where it becomes narrower than in the rest of its course. The first is at the upper end behind the cricoid cartilage; the second is at the level of the bifurcation of the trachea into right and left bronchus; while the third narrow point is where the oesophagus passes through the diaphragm. Unlike the abdominal parts of the alimentary tract, there is no peritoneal coat on the thoracic and cervical
oesophagus.
Research Oesophagus

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