THE SKELETON \J 



cartilage next above it, so that they are united to each other before they 

 reach the sternum. The eleventh and twelfth pairs are not connected at all 

 with the breast-bone. The last five pairs are called false ribs ; and of these 

 the eleventh and twelfth pairs are termed free or floating ribs. 



The collar-bone, which s attached to the sternum, and the 

 shoulder-blade, which lies behind the upper ribs, will be best 

 described with the bones of the arm. 



SUMMARY. 



TABLE OF THE BONES OF THE TRUNK. 



VERTEBRAL 

 COLUMN 



BIBS 



Neck 7 Cervical 



Back 12 Dorsal , 



Loins 5 Lumbar 



Sacrum 5 Sacral 



Coccyx 4 Coccygeal 



7 Pairs true 



5 Fairs false 



Small bodies. 



Processes \ S P inous - 



t Lateral small. 



Give attachment to ribs. 

 Larger bodies. 



{Spinous long. 

 Lateral 

 Articular united with 

 heads of ribs. 

 Very large bodies. 



T f Spinous. 



Long processes { ^^ 



United, forming a wedge. 



Fixed between 'hip-bones. 



Rudimentary. 



Correspond with tail in lower ani- 

 mals. 



Connected by their own cartilages 

 with breast-bone. 



8th, Qth, and loth pairs each con- 

 nected with the cartilage above 

 it. 



nth and I2th pairs floating or 

 free fixed at one end only. 



QUESTIONS ON LESSON II. 



1. Describe the structure of the vertebral column. What is the spinal canal '? 



2. Describe the structure of a vertebra. How many vertebrae belong to the 



neck, back, and loins respectively ? 



3. How are the vertebrae connected with each other ? On what does the 



flexibility of the vertebral column depend ? 



4. In what respects do the cervical, dorsal, and lumbar vertebrae differ from 



each other ? How do these differences affect their uses ? 



5. Describe the sacrtim and coccyx. 



6. Describe the general arrangement of the ribs. In what respects do they 



differ from each other ? 



7. What are the functions of the vertebral column and ribs ? 



