A15 Body Wall

Question 1

Describe the abdominal wall

Answer 1

The function of the body wall is to provide a durable & flexible covering to protect abdominal viscera.

Dorsal - caudal thoracic vertebrae, lumbar vertebrae, hypaxial m.
Lateral - muscles of the flank
Cranial - diaphragm
Caudal -pelvic inlet
Ventral - rectus abdominis & aponeuroses of abd. muscles

Question 2

Describe the connective tissue layers

Answer 2

Aponeuroses - sheet of white fibrous tissue that takes the place of a tendon in flat muscle having a wide area of attachment

Question 3

Describe the linea alba

Answer 3

• Midline between the left and right rectus abdominis m.
• origin: xiphoid cartilage
• insertion: prepubic tendon/pubic symphysis
• wider carnally & tapers causally
• umbilical cord attaches at umbilicus

Question 4

Describe the prepubic tendon

Answer 4

Prepublic tendon isn’t paired & is a common attachment for ventral abdominal muscles on the cranial pubis (rectus abdominis, linea alba, pectinous). It may include part of the tendons of origin of hindlimb adductor m.

Question 5

Explain the rictus sheath including its significance & the falciform ligament

Answer 5

• arrangement of abdominal muscle aponeuroses wrap around the rectus abdominis m. & insert along the linea alba
• external rectus sheath = ventral
• internal rictus sheath= dorsal

Falciform ligament is the remnant of embryonic ventral mesentery. it is a fold of peritoneum between the diaphragm & the liver & umbilicus & is where fat is frequently deposited.

Question 6

Describe the anatomy and contents of inguinal rings & canals in male & female

Answer 6

Superficial inguinal ring: a hole in the aponeurosis of external abdominal oblique
Deep inguinal ring: intersection of boundaries of free caudal edge of internal oblique, lateral border of rectus abdomens, transversalis fascia between transverse abdominis & peritoneum

Inguinal: space between deep & superficial inguinal rings where structures can leave/enter the abdominal cavity

A blind-ended portion of peritoneum runs through the inguinal canal & then subcutaneously; vaginal tunic in males, vaginal process in females

Question 7

Describe the muscles of the body wall including their attachments & functions

Answer 7

External abdominal oblique
Origin: from lateral ribs
Insertion: aponeurosis midline
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Internal abdominal oblique
Origin: tuber coax
Insertion: aponeurosis midline
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Transverse abdominis
Origin: last ribs & lumbar transverse processes
Insertion: aponeurosis midline
I

Rictus abdominis
Origin: sternum
Insertion: pubis via the prepubic tendon
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Question 8

Describe the epaxial & hypaxial muscle groups

Answer 8

Epaxial muscles:
- paired
- dorsal to transverse processes of vertebral column
- 3 parallel longitudinal muscle groups
- function: locomotion, extends vertebral column, bend trunk laterally
- transversaspinalis, longissumus, iliocostalis

Hypaxial muscles:
- Paired
- ventral to the transverse processes of vertebrae
- cervical hypaxial m. are flexors of the neck
- sublumbar hypaxial m. (Flexors of lumbar vertebrae)
- thoracic hypaxial m.