42 



HITCHCOCK'S ANATOMY 



103. General Remarks on the Spinal Column, — The 



Spinal Column viewed as a whole may be considered as 

 made up of four cones, owing to the different sizes of the ver- 

 tebrae. The apex of the upper one commences with the Atlas 

 and extends as far as the first dorsal vertebra. Here the 

 second one commences in an inverted position, extending over 

 the upper three dorsal vertebrae. The third reaches with its 

 base as far as the top of the Sacrum, where the inverted 

 fourth one terminates with the Coccyx. Viewed from the 

 front the spinal column should be in a straight line when in a 

 healthy condition ; but a lateral view shows two curves, one 

 at the lower part of the neck, and the other at the lumbar 

 vertebrae, the design of this curvature being to place the 

 head and its delicate contents upon an elastic and flexible 

 support, and the design of the straight position in the other 

 direction, being to give equal tension to the muscles on both 

 sides. 



104. Intervertebral Cartilage. — Between all the vertebrae 

 is placed a thick cushion of cartilage. This by yielding not 

 only allows a free and ready motion to the column as a whole, 

 but is an additional protection to the brain, by diminishing 

 the severity of any vibration communicated from below. 



105. Bones of the Head. — The Skull may be considered 

 as the superior expansion of the spinal column, when it — the 

 spinal column — is taken as the center of development of the 

 whole body, which contains in the cranium the brain, and in 

 the face most of the organs of sense. 



106. In the Cranium or true skull are eight bones: 



1 Frontal, 2 Temporal, 2 Parietal, 



1 Occipital, 1 Sphenoid, 1 Ethmoid. 



103. Of how many cones may the Spinal Column bo considered as composed? From 

 what direction does the Spinal Column appear in a straight line? W^hat curvatures does 

 a lateral view show ? 104. What substance do we find between the vertebrae? Give 

 its use. 105. What may the Skull be considered as? What organs does it contain? 

 106. Give the bones of the Skull. 



