Biology 122 Spring, 2008

Laboratory 13

Posterior Mediastinum, Sympathetic nervous system and diaphragm

OBJECTIVES

At the end of this lab you should:

1. Know the morphology and relationships of structures in the posterior mediastinum.

a. understand the relationships of the esophagus, trachea and great vessels from the superior into the posterior mediastinum.

b. understand the position and relationships of the descending aorta and inferior vena cave. Know where these vessels and the esophagus pass through the diaphragm

b. know the course of the Vagus nerve in the posterior mediastinum, including the recurrent laryngeal nerves.

c. understand the arterial supply and venous drainage of the esophagus, venous anastamoses and the significance of the esophageal submucosal venous plexus.

d. know the positions and significance of the azygos and hemiazygos veins and the thoracic duct

2. Be able to diagram and discuss the structure and composition of the sympathetic chain relative to its contributions from spinal nerves; know the position and composition of the sympathetic chain and sympathetic ganglia and the origin, course, and distribution of the gray and white rami communicates and splanchnic nerves.

3. Know the structure of the diaphragm, its parts (costal, sternal & crural diaphragm and central tendon), attachments and innervation.

PRELAB PREPARATION

1. Review the chapters in your textbook covering the lungs and pleural cavities (pp. 112-135). Review material on the mechanisms of respiration and the section on the diaphragm (pp. 325-331).

2. Read and/or review material in M&D covering the superior and anterior mediastinum. Read the section on the posterior mediastinum (pp. 177-184). Review introductory material on the autonomic nervous system (pp. 58-67) specifically on the formation and content of the sympathetic chain. Also you should review the concepts of collateral venous and arterial circulation and be able to diagram collateral routes involving the intercostal arteries and veins.