. Biology of the vertebrates : a comparative study of man and his animal allies. Vertebrates; Vertebrates -- Anatomy; Anatomy, Comparative. Production of Motion and Locomotion 655 duction of encircling ribs. Posteriorly in the belly region the original three layers of muscles remain unchanged, but anteriorly in the thoracic region the oblique muscles become broken up into external and internal intercostal muscles, which extend from rib to rib and aid in respiratory movements. In the neck region in front of the ribs the oblique layers furnish material for the scalenus muscles. Among birds the o
. Biology of the vertebrates : a comparative study of man and his animal allies. Vertebrates; Vertebrates -- Anatomy; Anatomy, Comparative. Production of Motion and Locomotion 655 duction of encircling ribs. Posteriorly in the belly region the original three layers of muscles remain unchanged, but anteriorly in the thoracic region the oblique muscles become broken up into external and internal intercostal muscles, which extend from rib to rib and aid in respiratory movements. In the neck region in front of the ribs the oblique layers furnish material for the scalenus muscles. Among birds the oblique muscles are poorly developed, the transversus is absent, and the rectus abdominis, reduced in size, is posteriorly unseg- mentated. This sacrifice of the ventral axial muscles is compensated, how- ever, by an excessive elaboration of the appendicular muscles of flight, which come to overlie the muscles of the body wall. A familiar example of them is the "white meat" on the breast of roast chicken. Cephalohumera! Sternomastoid \ Temporal \ \ Masseter \ \ * Levator Scapulae Ventralis / Acromiotrapezius / / Acromiodeltoid ! 1 / Spinodeltoid J-l-/r~^ /„,„., Latissimus Dorsi .Serratus Ventralis // " J // I J 7. Digastric / j I Geniohyoid ' / Stylohyoid ; Sternohyoid Meditriceps' External Oblique .Tensor Fasciae Latae ,Gluteus Maximus Z^ ..Obturator Internus ^s.*- Ischium M""- Caudofemoralis _ /Illllh^c . . / Tr~Sartonus =__^r~Semitendinosus Brachialis Ectotriceps Biceps Femoris Fig. 587. The muscles of a cat. (After Sayles.) \ Gastrocnemius The oblique muscles in mammals give rise to the intercostal and serratus muscles, which come to assume more of a dorsal than ventral position, although still supplied from the ventral branch of the spinal nerves (Fig. 587). Other mammalian muscles of ventral axial origin are the psoas muscles of the posterior abdominal wall, and the colli muscles of the neck region. Furthermore, even in the reptiles the rectus
Size: 2548px × 981px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, booksubjectanatomycomparative, booksubjectverte
