Lecture 23 - MSK Abdominal Wall Flashcards
List the boundaries of the abdominal cavity
cranial - diaphragm
caudal - pelvic inlet
dorsal - vertebral column & hypaxial muscles
ventral - linea alba
Define the flank region
lateral, caudal abdominal wall (no ribs)
What muscle makes up the fold of the flank?
cutaneous trunci
What is the use of this flank fold?
handhold for restraining small ruminants
what abdominal muscles contribute to the paralumbar fossa
internal abdominal oblique
Define the boundaries of the paralumbar fossa
transverse processes of lumbar vertebrae
last rib
tension ridge (IAO)
What is a clinical use of the paralumbar fossa?
site of laparotomy (ruminants) and laparoscopy (equine)
Where does the subiliac lymph node drain?
to the medial iliac lymph node
What animals have a subiliac lymph node?
ruminant, horse, and pig
List the layers of the abdominal wall (superficial to deep)
external abdominal oblique
internal abdominal oblique
transversus abdominis
rectus abdominis
What is the purpose of the elastic abdominal tunic? Where is it found?
provides additional passive support to the abdominal wall
it covers the surface of the external abdominal oblique
What vessel may be disrupted in dorsal flank surgery or laparoscopy?
deep circumflex iliac a.
What is meant by a “heave” line and who gets one?
a prominent musculotendinous junction between hypertrophied muscle of EAO and aponeurosis
severe equine asthma patients
define the inguinal canal
pathway between abdominal wall muscles and their aponeuroses
What forms the rectus sheath? Where are they?
formed by the aponeuroses of the EAO, IAO, TA surrounding the RA
external - superficial RA
internal - deep RA
What is the clinical importance of the external rectus sheath?
strongest suture holding layer when closing a paramedian incision
What is the linea alba?
ventral midline junction of rectus sheaths that extends from xiphoid process to pubis
What are the features of the linea alba that make it a good choice for abdominal incision?
avascular and no nerves, strong suture properties
List the sequential layers for a ventral midline celiotomy
- skin
- SQ tissue
- linea alba
- retroperitoneal fat
- peritoneum
List the sequential layers of a paramedian incision
- skin
- SQ tissues
- external rectus sheath
- rectus abdominis
- internal rectus sheath
- retroperitoneal fat
- peritoneum
List the sequential layers for a laparotomy
- skin
- SQ tissue
- EAO
- IAO
- TA
- peritoneum
When closing, what tissues are considered our strength-holding layers
- TA/IAO
- EAO
- skin
- maybe SQ layer
What are the origins of the external abdominal oblique? Where do the fibers run?
thoracolumbar fascia and lateral surface of ribs
caudoventrally
What are the origins of the internal abdominal oblique? Where do the fibers run?
tuber coxae and thoracolumbar fascia
cranioventrally
What are the origins of the transversus abdominis? Where do the fibers run?
lumbar transverse processes
dorsoventrally
What are the origins of the rectus abdominis? Where do the fibers run?
costal cartilage/sternum and brim of pubis
craniocadually
What is unique about the rectus abdominis?
divided into segments by the tendinous inscriptions (6-pack)
What is unique about the internal abdominal oblique?
covers paralumbar fossa
What is unique about the tranversus abdominis?
spinal nerves on the surface
How is the superficial inguinal ring formed
slit in the aponeuroses of the external abdominal oblique
what passes through the inguinal canal
external pudendal a/v
genitofemoral n.
spermatic cord
vaginal process
how is the deep inguinal ring formed
intersection of the inguinal ligament, caudal border of the IAO, and lateral border of the RA
When would we do a paramedian cut versus a ventral midline cut
if the linea alba is infected or if needing access to a particular organ
Attachment of:
iliocostalis system
ilium to rib 1
Attachment of:
longissimus system
ilium to skull
Attachment of:
transversospinalis system
sacrum to skull
Attachment of:
semispinalis capitis
thoracic vertebrae to the skull
Attachment of:
splenius
spinous processes T1-3 and median raphe to the skull
Attachment of:
longus colli
ventral vertebral bodies and transverse processes T6-C1
Attachment of:
longus capitis
cervical transverse processes to skull
What are the extensors and lateral movers of the vertebral column
iliocostalis, longissimus, and transversospinalis
What are the extensors of the head and neck
semispinalis and splenius
T/F: splenius and semispinalis secondarily laterally flex the neck
True
Action of:
longus colli
flex neck
Action of:
longus capitis
flex atlanto-occipital joint
draw neck ventrally
