The mediastinum is a membrane of the thoracic cavity in the body. It resides between the lungs and is made up of a portion of the pleura of the lungs. What is this pleura called?
Parietal Pleura. Parietal pleura is the outermost structure of the lungs as opposed to the visceral pleura which resides on the inside.
The mediastinum is divided into two major categories. Superior and Inferior. Which of the two is further divided into the anterior, middle, posterior compartments? Does the anterior, middle or posterior compartment contain the heart in its pericardial sac?
The Inferior compartment of the mediastinum is divided into anterior, middle, and posterior compartments. The middle mediastinum contains the pericardial sac encasing the heart.
The heart can be used as a reference for the portions of the inferior mediastinum. What two divisions does it make up in the inferior mediastinum if it makes up the middle mediastinum?
The heart is the boundary for the anterior and posterior mediastinum.
Of the posterior and anterior mediastinum, which area is smaller?
The anterior mediastinum is smaller than the posterior mediastinum.
The superior tends to house a lot more items than the anterior mediastinum. It houses the great vessels SVC, brachiocephalic vein, origins of the brachiocephalic artery, left subclavian a. and left common carotid. What else does it house if nerves and viscera are the remaining categories?
As far as nerves go, it houses the vagus, phrenic and left recurrent laryngeal nerves. The viscera that it contains include the espohagus, trachea, thoracic duct, thymus, and lymph nodes.
The anterior mediastinum contains only visceral bodies. If lymph nodes are one of the items. What is the other?
The thymus is also housed in the anterior mediastinum.
The thoracic duct contains lymph that dumps into what vein?
The cephalic vein carries lymph that eventually dumps into the cephalic vein.
The posterior mediastinum is the most busy area of the mediastinum containing many vessels of the heart. What two vessels that we have discussed are in the posterior mediastinum?
The azygos vein and the thoracic aorta.
Is the esophagus or the trachea contained in the posterior mediastinum?
The esophagus is contained in the posterior mediastinum.
The splanchnic nerve is found in what compartment of the mediastinum?
The splanchnic nerve is found in the inferior mediastinum but more specifically the posterior mediastinum
Which sac, the lesser or grater sac is posterior to the stomach?
The lesser sac is posterior to the stomach
Peritoneal folds hold the organs in place. What does the ventral mesentery make up? What does this omentum separate with regards to the stomach and the duodenum?
The lesser omentum is made by the ventral mesentary. It separates the lesser curvature of the stomach and the liver from the duodenum.
The arteries of the gut tube have to move through the dorsal or ventral mesentary?
The arteries of the gut tube have to penetrate the dorsal mesentary.
The stomach has a lesser and greater curvature with the lesser curvature being more superior in the anatomical position. With this being the case, what is the omentum located below the stomach along the grater curvature called? What is it derived from?
The omentum located along the greater curvature of the stomach is called the greater omentum. It is derived from the dorsal mesentery during development.
There are two arteries that run along the greater curvature of the stomach and anastomose with one another. What are their names?
The two arteries are called the left and right gastroepiploic arteries.
Blood supplies cannot penetrate mesentaries. T or F.
True. The blood supply for a particular organ must be found within the mesentery that the organ resides in.
What is the name of the mesentary that suspends the ileum and the jejunum? What is the significance of this boundary with respect to blood supply?
The name of the mesentery is mesentery proper. Therefore the blood supply must be found in the mesentery proper in order to supply the ileum and jejunum.
Men with beer bellies have a lot of fat in the abdominal region. Is this fat found on the outside of the anterior mesentery or within the anterior mesentery?
Men with beer bellies have a significant amount of fat within the inferior mesentery.
Structures that are behind the peritoneum are deemed retroperitoneal while those that are suspended are given what term?
Intraperiotoneal is the term for organs that are suspended within the fold of peritoneum or mesentery.
True or False. The ascending colon started out intraperitoneal but then became retroperitoneal due to the space constraints of the body cavity?
True. In the developing human, the ascending colon started off intraperiotoneal, however, as the human progressed to develop, the structures became retroperitoneal.
There are four quadrants of the abdomen. In the upper right there is the liver, gall bladder, and what other structure of the large intestine?
The transverse colon.
The upper left quadrant of the abdomen contains the jejunum and transverse colon. What are the remaining two organs?
The spleen and the stomach are located in the upper left quadrant of the abdomen.
The lower right contains three structures. The ileum, cecum, and what other structure?
The ascending colon.
The jejunum is present in two quadrants of the body. What are they?
The upper and lower left quadrants.
If the lower left quadrant houses the jejunum and the descending colon, what else is present in the lower left hand quadrant?
The sigmoid colon is present in the lower left quadrant of the abdomen.
What is the name of the sheath that surrounds the lateral, medial, and posterior cords of the breachial plexus?