The development of the human body; a manual of human embryology . the sac into theveins being guarded by a valve due to the oblique direc-tion taken by the outgrowth. From each lymph heartbranches, which anastomose and radiate in all directions,grow outward toward the skin which they reach in em-bryos of about 18 mm., and in later stages continue toextend in a radiating manner until they form a subcu-taneous network over the anterior half of the body. Inthe mean time the lymph hearts have separated from theirpoints of origin (Fig. 153, A, ALH), with which, however,they remain connected by a du
The development of the human body; a manual of human embryology . the sac into theveins being guarded by a valve due to the oblique direc-tion taken by the outgrowth. From each lymph heartbranches, which anastomose and radiate in all directions,grow outward toward the skin which they reach in em-bryos of about 18 mm., and in later stages continue toextend in a radiating manner until they form a subcu-taneous network over the anterior half of the body. Inthe mean time the lymph hearts have separated from theirpoints of origin (Fig. 153, A, ALH), with which, however,they remain connected by a duct, and from this a branchgrows backward, following the line of the vagus nerve (Fig153, A, TD). The branch on the left side soon meets withthe aorta and, using this as a guide, grows more rapidlythan its fellow on the right and becomes the thoracic duct, 2Q2 THE DEVELOPMENT OF THE HUMAN BODY. or, rather, since it divides just before it reaches the aortaand sends a branch backward on either side of that vessel,it gives rise to two thoracic ducts (Fig. 153, B).. Fig. 153.—Diagrams showing the Arrangement of the LymphaticVessels in Pig Embryos op (A) 20 mm. and (S) 40 mm. ACV, Jugular vein; ADR, suprarenal body; ALH, anterior lymph heart;Ao, aorta; , deep lymphatics to. the arm; D, diaphragm; Dubranches to duodenum; FV, femoral vein; H, branches to heart; K,kidney; LegD, deep lymphatics to leg; Lu, branches to lung; MP,branches to mesenteric plexus; CE, branch to oesophagus; PCVcardinal vein; PLH, posterior lymph heart; RC, receptaculumchyh; RLD, right lymphatic duct; ScV, subclavian vein; SV sciaticvein; St, branches to stomach; TD, thoracic duct; WB, Wolffianbody.—(Sabin.) THE LYMPHATICS. 293 In embryos of 20 mm. a second pair of lymph heartsdevelops at the junction of the sciatic veins with the cardi-nals (Fig. 153, A, PLH), and from these branches grow to-ward the surface and radiate subcutaneously, similarly tothose from the anterior hearts, with which they eventual
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectembryol, bookyear1902
