112 ELEMENTS OF MAMMALIAN ANATOMY 



MUSCLES OF THE BODY WALL 



(176) Scalenus, divisible into several parts which may be 

 described as separate muscles. 



(a) Scalenus mcdius, sixth to ninth ri])s to join rest of muscle 

 near first rib. 



(/)) Scalenus posterior, third or fourth rib, joins rest of muscle 

 as (a). 



(c) Scalenus anterior, second and third ribs, joins either 

 portions of muscle near first rib and the entire muscle is inserted 

 into the transverse processes of all cervical vertebrae. Flexes 

 neck and draws ribs forward. 



(177) Transversus costarum {stemocosialis externus) , sternum 

 to first rib; draws sternum forward. 



(178) Seratus posterior superior, first nine ribs to dorsal 

 medial raphe from the atlas to the tenth thoracic vertebra; 

 draws ribs forward. 



(179) Serratus posterior inferior, last four or five ribs to 

 lumbar spinous processes; draws ribs forward. 



(180) External oblique, last nine or ten ribs and lumbodorsal 

 aponeurosis to the median ventral raphe and linea alba from 

 the seventh costal cartilage to the pubic tubercle; constrictor 

 of abdomen. 



(181) Internal oblique, lumbar aponeurosis from fourth to 

 seventh lumbar vertebrae, aponeurosis from ventral half of iliac 

 crest, and the three crural arches to the ventral midline; com- 

 pressor of abdomen. 



(182) Transverse abdominal, false and floating ribs, trans- 

 verse processes of lumbar vertebrae, ilium, and crural arches to 

 linea alba; constrictor. 



(183) Rectus abdominis, tubercle of pubis to first and second 

 costal cartilages and sternum; retracts ribs and sternum and 

 compresses abdomen. . 



(184) External intercostals, between ribs in intercostal spaces; 

 protractors. 



