280 



LECTURE XII. 



Of the Blood-vessels and their action — Circulation of 

 the Blood — Importance of a knowledge of the Struc- 

 ture of Vessels — Views regarding the Structure of the 

 Cajyillaries — Protoplasm Walls of Capillary Vessels 

 — Bioplasm of the Capillaries — Action of the Tissue 

 of the Capillary Walls — Action of the Bioplason — Of 

 the Arteries — Of the Veins — Examination of the 

 Arteries and Veins — Action of the Contractile Fibres 

 of Vessels — Distribution of Nerves to Arteries — Nerves 

 to Veins — Of the Nerves distrihuted. to the Capil- 

 laries — Central Origin and Connections of the Nerves 

 to the Capillaries — Neiv Observations on the Nerves 

 of the Capillaries of the Bafs-vnng — Method of de- 

 monstration — Action of the Nerves of the Capillary 

 Vessels — Are they Sensitive, or Motor, Nutritive, or 

 Secretory ? — Their Connection with Ganglia — Bhy- 

 siological Experiments — Of the Self-acting Mechanism 

 by y;hich the Supp)ly of Blood to the Tissues is Benu- 

 lated — Action of Nerve Fibres in Acute Inj1,ammation 

 — Alteration of Nerve Fibres in Chronic Diseases — 

 Degeneration of Vessels. 



292. Circulation of the blood in the yessels. — The 



imtrition and maintenance, as well as the gi-owth, of 

 every tissue in the body of vertebrate animals are 

 dependent entirely npon the distribution of a due 

 supply of healthy blood in their immediate neigh- 

 bourhood. The blood does not touch the tissue to 

 be nourished, but fluid transudes through the thin 

 walls of the vessels along which the blood is pro- 

 pelled. This is imbibed by the tissue, and being kept 

 constantly moving in its interstices, preserves the 



