202 



HEALTH AND DISEASE 



outer condyle behind is a deep depression termed the supra-condyloid 



fossa. 



Patella (fig. 310). — This is a small irregular bone analogous to the 



knee-cap of man, and in the horse fre- 

 quently becomes displaced. Behind it 

 is covered with articular cartilage, and 

 conies into contact with the trochlea 

 of the femur, over which it plays in 

 pulley -like fashion as a part of the 

 stitle-joint. 



Tibia or Second Thigh (fig. 3ii). 



— A long bone extending from the 

 femur to the hock joint. It is broad 

 above and narrow below. The superior 

 extremity articulates with the condyles 

 of the femur, and is divided into two 

 lateral articular portions by a conical 

 projection [tibial spine). In front, and 

 extending for some distance down the 

 bone, is a projecting ridge, inclining 

 somewhat outward; this is known as 



Fig. 309. —Os Femoris (Posteiior Aspect) 



^ (ireat Trochanter. - Trochanteric Fossa. 



■* Trochanter Minor Externus. "* Supra-condyloid 

 Fossa. ^ External Condyle. ^ Inter-condyloid 

 Fossa. ^ Internal Condyle. ** Internal Trochlea. 

 ^ Nutritive Foramen. ^^ Internal Trochanter. 



^^ Fossa for attachment of Ligamentum Teres. 

 12 Head of Femur. 



Fig. 310.— Patella (Superior and Posterior 

 Face) 



' Superior Face. ~ Articular Face. 

 ' External Border. 



the "tibial crest". On the outer side of the head of this bone above, 

 a small smooth space is noticed for articulation with the fibula. 



The lower extremity of the bone, smaller than the upper, presents two 

 deep grooves and three prominent ridges which are covered with cartilage 

 and articulate with the astragalus to form the " true hock joint ". 



