Body Wall Flashcards
What are the boundaries of the body wall?
dorsal: thoracic vertebrae, lumbar vertebrae, by-axial muscles
lateral: muscles of flank
caudal: pelvic inlet
ventral: rectus abdominus & aponeuroses of abdominal muscles
List paired abdominal wall muscles.
external abdominal oblique
internal abdominal oblique
transverse abdominis
rectus abdominis
Describe the abdominal oblique.
origin = lateral ribs
insertion = aponeurosis midline
runs in craniodorsal -> caudoventral direction
part of rectus sheath
Describe the internal abdominal oblique
origin = tuber coaxae
insertion = aponeurosis midline
runs in caudodorsal -> cranioventral direction
part of rectus sheath
What is an aponeurosis?
sheet-like tendon
translucent
Describe the transverse abdominis.
origin = last ribs & lumbar transverse processes
insertion = aponeurosis midline
runs dosoventrally
part of rectus sheath
Describe the rectus abdominis.
origin = sternum
insertion = pubis via prepubic tendon
runs craniocaudal
fibrous bands across
What provides strength to the abdomen?
lattice-work fibre pattern of abdominal muscles
Explain the actions of the abdominal muscles.
contraction = doming of diaphragm
fixed diaphragm + contraction = increased abdominal pressure
posture & movement
What are the nerve & vascular supplies to the abdominal muscles?
caudal intercaustal nerves
ventral lumbar nerves
cranial superficial epigastric arteries
caudal superficial epigastric arteries
What is the rectus sheath?
external = combined aponeurotic tendons ventral to rectus abdominus
internal = combined aponeurotic tendons dorsal to rectus abdominus
external & internal join = linea alba
What is the falciform ligament?
fold of peritoneum between diaphragm, liver, umbilicus
CRANIAL TO UMBILICUS
- What are the components of the external rectus sheath?
- Internal rectus sheath?
- external abdominal oblique aponeurosis & ventral internal abdominal oblique aponeurosis
- transverse abdominus aponeurosis & dorsal internal abdominal oblique aponeurosis
AT UMBILICUS
- What are the components of the external rectus sheath?
- Internal rectus sheath?
- external abdominal oblique aponeurosis & internal abdominal oblique aponeurosis
- transverse abdominus aponeurosis
CAUDAL TO UMBILICUS
- What are the components of the external rectus sheath?
- Internal rectus sheath?
- external abdominal oblique aponeurosis & internal abdominal oblique aponeurosis & transverse abdominus aponeurosis
- N/A
Describe the linea alba
midline between rectus abdominus muscle bellies
origin = xyphoid
insertion = prepubic tendon
What is an inguinal ring?
superficial = natural opening in aponeurosis of EAO deep = intersection of free caudal edge of IAO, lateral border of RA, transversals fascia between TA &peritoneum
What is the purpose of the inguinal rings?
to allow structures to enter/leave abdominal cavity
What is the inguinal canal?
the space between the deep & superficial inguinal rings
What is a vaginal tunic/process?
blind-end pouch of peritoneum
tunic - male
process - female
goes through inguinal rings
Describe the vaginal tunic.
substantial
surrounding testes & spermatic cord structures
goes through inguinal rings
Describe the cremaster muscle.
alongside vaginal tunic
from caudal border of IAO
pulls testes close to body wall
goes through inguinal rings
Describe the vaginal process.
surrounds round ligament of uterus
goes through inguinal rings
Draw & label a schematic of the inguinal canal of a male dog.
add photo
List the muscles of inspiration.
scalenus serrates dorsalis cranialis rectus thoracic external intercostal muscles internal intercostal muscles
List the muscles of expiration
serrates dorsalis caudalis
internal intercostal muscles
Describe the epaxial muscles.
paired
dorsal to transverse processes of vertebrae
3 systems of muscles on each side
What is the function of epaxial muscles?
locomotion
bilateral contraction = extends vertebral column
unilateral contraction = bends body to one side
Describe the transversospinalis system.
muscle groups with lots
ligamentous has nuchal ligament & supraspinous ligament
Describe the longissimus system.
muscle group from head to ilium
Describe the illiocostalis system.
muscle group from caudal neck to ilium
Draw & label a schematic of the epaxial muscles.
add photo
Describe the hypaxial muscle groups.
ventral to transverse processes
cervical (flexors of head & neck)
thoracic
sub lumbar (flexors of lumbar vertebrae)
