VAN 121: Veterinary Gross Anatomy-II (2+2)

ABDOMEN (EXTERIOR)

Abdominal muscles

• Recognise the four abdominal muscles. Details of their attachment cannot be verified at present. Recognise the transverse abdominis in the lateral wall. Its fibres are running across the body. The lower part of the muscle is aponeurotic forming a sheath with the aponeurosis of the internal oblique for the rectus abdominis. In the abdominal floor, the rectus abdominis is situated.

• The four abdominal muscles on either side of the linea alba, arranged in layers; these from without inwards

• Obliquus abdominis externus
• Obliquus abdominis internus
• Rectus abdominis
• Transversus abdominis
• Cremaster externus

Tunica flava abdominalis

• This is a yellow elastic sheet - the abdominal tunic underneath the cutaneous muscle.
• It is very thick and closely adherent to the aponeurotic part of the external oblique muscle but closely covers its muscular part.
• It is thick towards the common prepubic tendon of the abdominal muscles and the linea alba.
• It is reduced to a very thin layer as it reaches the muscular portion of the external oblique muscle and thereafter it disappears.
• Anteriorly, it extends over some of the intercostals and the posterior digitations of the serratus thoracis. Posteriorly, it is attached to the external angle of the ilium and lumbo-dorsal fascia.
• The suspensory ligament of the prepuce in the male and the mammary gland in the female is derived from the external face of this tunic.
• It forms the elastic bandage and supports the abdominal muscles in bearing the weight of the viscera. View