PELVIC LIMBS 721 



of the long bones of animals, the name was transferred to the bone 

 itself. Celsus first employed the term in human anatomy. Tibia was 

 also used for the whole lower leg, the leg-armor being called tibialia. 

 Galen called the tibia cneme, which is retained in gastrocnemius. 

 Because in man it can be felt through the skin, it is called the shin 

 bone, shin being derived from the old German Schin, the skin, whence 

 the German word das Sohienbein. The French is le tibia. 



Determination. If the tibia be held with the superior extremity 

 upward and the anterior crest toward the student, the malleolus at the 

 lower end will be on the side to which the bone belongs. 



Articulation. The tibia articulates with the femur, the patella, 

 the fibula, and the astragalus. 



Muscular Attachments. To the outer surface is attached the 

 tibialis anticus. To the posterior surface: the popliteus, the tibialis 

 posticus, the flexor longus digitorum, and the flexor longus hallucis. 

 To the tubercle : the ligamentum patella?, or tendon of the quadriceps 

 extensor femoris. To the anterior border of the shaft : the biceps 

 femoris. To the inner tuberosity : the semimembranosus. To the 

 internal surface of the shaft : the sartorius. 



Blood-Supply. The principal blood-supply of the tibia is de- 

 rived from the nutrient artery of the shaft, which springs from a 

 branch of the popliteal forming the upper part of the tibialis posticus, 

 or sometimes from the tibialis anticus. 



Ossification. The tibia develops from four centres, one for the 

 upper extremity, one for the lower extremity, one for the shaft, and 

 one for the tubercle (Fig. 549). 



VARIATIONS IN THE TIBIA. 

 VARIATIONS IN SIZE. 



The measurements of the tibia are taken as follows : 



The maximum length is the distance on the long axis from the 

 highest point on the head to the tip of the malleolus. 



The width at the upper end is the greatest transverse diameter 

 between the lateral prominences of the tuberosities. 



The width at the lower end is the greatest transverse diameter on 

 a transverse line drawn from the greatest convexity of the malleolus 

 to a point opposite the most projecting point of the fibular articular 



facet. 



46 



