6 
MAMMALIAN ANATOMY 
pectoralis and the latissimus dorsi; the deltoid muscles covering 
the shoulder joint. 
Muscles of the Vertebral Column. —Note that it is only in the 
lumbar region that these are not covered by superficial muscles of 
other groups, and thus contribute to the external contours of the 
body. 
Intercostal Muscles. —Note that these muscles fill in the spaces 
between the successive ribs. 
Abdominal Muscles. —Note particularly the two rectus 
abdominis muscles, arranged longitudinally one upon each side 
of the midventrally located linea alba, which extends from the 
posterior end of the sternum to the symphysis pubis. The other 
abdominal muscles are disposed in three layers forming the 
lateral and latero-ventral walls of the cavity. 
Muscles of the Hip Region. —Note particularly the gluteus 
group and compare with man, in whom these muscles are so 
much more prominently developed to hold the legs in a straight 
line with the axis of the trunk. 
Flexors and Extensors of the Appendages.— Among these, 
note, in the anterior appendage, the biceps brachii and the triceps 
brachii, and the flexors and extensors of the carpus and fore foot 
(hand), with their respective tendons of insertion. In the pos¬ 
terior limb, note the extensor quadriceps femoris with its relation 
to the patella, and the flexors of the leg, forming at the knee joint 
the “outer and inner hamstrings;” the triceps surse (calf of the 
leg) and its tendon of Achilles, and the tibialis anterior and 
other extensors of the foot with their tendons of insertion. 
(The foot is habitually over extended, i.e., ‘‘flexed” in the 
wrong direction.) 
2. Identification of Superficial Muscles and Their Tendons upon 
the Living Human Body. 
Locate these by palpation with the muscles in question strongly 
contracted, and identify the muscles or muscle groups by referring 
to manikins, plaster casts showing muscle dissections, and atlases. 
Record the location of these muscles and tendons upon the outline 
drawings of the human body , noting their relationship to superficial 
skeletal features already recorded. 
