LECTURE IV 

 POSTERIOR LIMB 



The posterior limb contains 20 bones, and is divided for study 

 into pelvis, thigh, leg^, and foot. 



Pelvis. — The pelvis is divided into two halves, each half being 

 composed of three bones closely united. These are: (a) the 

 ilium, the external angle of which forms the prominence of the 

 hip. Its internal angle articulates with the sacral vertebrae at 

 the highest point of the croup. Its shaft articulates at the 

 cotyloid cavity with the ischium and pubis. The three bones of 

 the pelvis form at this point the cotyloid cavity into which fits 

 the head of the humerus at the hip joint. (6) The ischium 

 forms the posterior portion of the floor of the pelvic cavity 

 through which the young must pass at birth. It articulates at 

 the cotyloid cavity with the two other bones of the pelvis. Its 

 posterior angle forms the prominence commonly known as the 

 pin bone, (c) The pubis forms the front part of the floor of the 

 pelvic cavity and articulates with the ilium and ischium at the 

 cotyloid cavity. To the breeder, the pelvis is for obvious rea- 

 sons, a most important part. These bones are distinct in early 

 life, but become united as the animal grows older. The two 

 halves of the pelvis bound the nelvic cavity, w'hich contains the 

 rectum, bladder, and sexual organs. Each half of the pelvis 

 articulates with the sacrum at the croup. 



Thigh. — One bone only, the femur, is contained in the thigh. 

 This bone articulates above with the pelvis and below with the 

 larger of the two leg bones, the tibia, and with the patella. The 

 femur belongs to the group which we have classified as long 

 bones, and is the heaviest and strongest bone in the body. This 

 bone offers for study a shaft and upper and lower extremities. 

 The shaft shows four faces, — external, internal, and anterior, 

 w^hich are smooth and convex, and a posterior face which is 

 rough and irregular on the surface. On the upper extremity we 

 find a smooth rounded head which articulates with a deep cavity 

 in the pelvic bone above. On the external side and projecting 



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