,\58 VISCERAL ANATOMY. 



Veins, open into the splenic and mesenteric veins. 



Nerves, from the solar plexus, forming a Splenic Plexus. 



What is the Lesser Pancreas ? A lobe of the head of the pancreas; 

 sometimes detached therefrom, in which case it opens by a duct into the 

 duodenum about an inch above the orifice of the pancreatic duct. 



THE DUCTLESS GLANDS. 



Name the so-called Ductless Glands. They are the Spleen, Supra- 

 renal Capsules, Thyroid and Thymus Glands. The first two are in the abdo- 

 minal cavity, the thyroid gland is in the front of the trachea, and the thymus 

 gland is in the anterior mediastinum of the thorax. These organs have no 

 excretory ducts, and their functions are unknown. 



THE SPLEEN. 



Describe the Spleen. The spleen is a soft, spongy and very vascular 

 organ, about 5 by 3 by 2 inches, from 6 to 10 ounces in weight, and situated 

 deeply in the left hypochondrium, embracing the cardiac end of the stomach, 

 to which it is connected by the gastro- splenic omentum. Its 



Outer Surface, is convex, corresponds to the 9th, loth and nth ribs, 



and is in relation with the inferior surface of the 

 FIG. 77. 



diaphragm. 



Inner Surface, is concave, and embraces the cardiac 



or splenic end of the stomach. 

 Borders, the anterior is thin and often notched ; the 



posterior is thick and lies on the left kidney. 

 Suspensory Ligament, attaches the upper extremity to 



the diaphragm, and is a fold of peritoneum. 

 Hilum, a vertical fissure about the middle of the con- 

 cave surface. It is pierced by the vessels, lymphatics 

 and nerves. 



Peritoneal, or Serous Coat, covers the whole organ, except at the attach- 

 ments of the suspensory ligaments and the gastro- splenic omentum. 

 Fibro-elastic Coat, or Tunica Propria, is reflected at the hilum upon the 

 vessels, and gives off numerous bands (trabecultz), which bound the 

 lacunar spaces (areolce) of the organ. 



Malpighian Corpuscles, are lymphoid sphenoidal expansions of the 

 outer coat of the small arteries, and average in diameter about the ^ 

 of an inch. They are attached to the arterioles of the organ in groups 

 of 6 or 8, and are usually pierced by an artery. Their reticulum is slender 

 and open, densely filled with lymphoid corpuscles, and well supplied 

 with capillaries. They have no capsule. 



