ANATOMY IN A NUTSHELL. 



339 



nient ( a part of the cord with a pair or nerves ) has a blood supply which is 

 made by the anterior and posterior spinal, reinforced by the lateral spinal, 

 making a ring around the segment. Branches are given from each segment 

 to the segment above and below. The blood supply of the vertebral column and 

 its ariculation is the vertebral, occipital, ascending pharyngeal, ascending 

 cervical, intercostal, lumbar, ilio-lumbar, sacra media, and lateral sacral. The 

 nerve supply is from the spinal nerves. 



LESSON XCVI. 



Brain. (Plates CLXVIII -CLXXXIII.) 



There is but one nervous system, consisting of three great divisions. The 



brain and spinal cord make the central system, the twelve pairs of cranial 



and the thirty-one pairs of spinal nerves make the peripheral system, and the 



third division is called the sympathktic system. This last svsteni is called 



PLATE CLIX. 



ASCENDING COLON 



CAECUM. ' ^§^-=^^5^ 4PPFN0IX 



The Ileo-Ctecal Valve. 



the nerve of organic life while the central one is called the nervous system of 

 animal life. The specific gravity of the nervous system is L.036, the brain 

 1.038 and the spinal cord 1.034. The reaction is alkaline, which is Lessened by 

 activity, owing to lactic acid being developed. The white matter is more 

 alkaline than the gray. The brain is a collection of gray ganglia connected by 

 white commissures. 



The following are the principal transverse commissures! 



1. Anterior commissure. 



2. Middle commissure. 



3. Posterior commissure; 



4. Corpus callosum. 



5. Optic commissure. 



6. Pons Varolii. 



