Question

- describe the muscle and bones of thorax

- give a clinical summary of mediastinum and related structures

- text is limited for 2 paper

Answer 1

1. The thoracic vertebrae forms the bones of thorax. This includes twelve rib pairs and the sternum. The costal cartilages are the ones that connects the ten pairs of ribs located in the upper portion to the sternum.

The thoracic cavity widens from the first to third rib. It gets more widened from third to seventh forming a cone like structure. The next seventh to twelfth rib pairs, the thoracic cavity gets a bit narrowed down and the rib length are comparatively shorter here.

The sternum which is also known as the breast-bone, is comprised of the three parts namely:

1. The xiphoid process/xiphisternum
2. The body
3. The manubrium

The costal cartilages along with sternum and the ribs form a container like structure for heart and lungs. This opening is filled completely with diaphragm and is usually termed as the inferior or lower thoracic aperture.This also marks the separation of thorax and abdomen.

2.The mediastinum is one of the compartment within the thoracic cavity which is located in the central region. It usually contains the following: the trachea, the heart and its vessels, the lymph nodes of chest, the thoracic duct, the esophagus and cardiac nerves.

The mediastinum is present in the thorax and pleurae is the structure that encloses it from right and left area. The back portion of it is surrounded by the spine, the sides are lined by the lungs and the fron portion has the walls of the chest. The frontal and dorsal regions are extended by sternum and vertebral column respectively.The mediastinum can be categorized as:

1. The superior mediastinum.
2. The inferior mediastinum
3. the thoracic plane,

Hence, the complete central part of the body is composed of the this structure and has most of the main functioning organs and nerves of the body.