Lecture 23 - MSK Abdominal Wall

Question 1

List the boundaries of the abdominal cavity

Answer 1

cranial - diaphragm

caudal - pelvic inlet

dorsal - vertebral column & hypaxial muscles

ventral - linea alba

Question 2

Define the flank region

Answer 2

lateral, caudal abdominal wall (no ribs)

Question 3

What muscle makes up the fold of the flank?

Answer 3

cutaneous trunci

Question 4

What is the use of this flank fold?

Answer 4

handhold for restraining small ruminants

Question 5

what abdominal muscles contribute to the paralumbar fossa

Answer 5

internal abdominal oblique

Question 5

Define the boundaries of the paralumbar fossa

Answer 5

transverse processes of lumbar vertebrae
last rib
tension ridge (IAO)

Question 6

What is a clinical use of the paralumbar fossa?

Answer 6

site of laparotomy (ruminants) and laparoscopy (equine)

Question 7

Where does the subiliac lymph node drain?

Answer 7

to the medial iliac lymph node

Question 8

What animals have a subiliac lymph node?

Answer 8

ruminant, horse, and pig

Question 9

List the layers of the abdominal wall (superficial to deep)

Answer 9

external abdominal oblique
internal abdominal oblique
transversus abdominis
rectus abdominis

Question 10

What is the purpose of the elastic abdominal tunic? Where is it found?

Answer 10

provides additional passive support to the abdominal wall

it covers the surface of the external abdominal oblique

Question 11

What vessel may be disrupted in dorsal flank surgery or laparoscopy?

Answer 11

deep circumflex iliac a.

Question 12

What is meant by a “heave” line and who gets one?

Answer 12

a prominent musculotendinous junction between hypertrophied muscle of EAO and aponeurosis

severe equine asthma patients

Question 13

define the inguinal canal

Answer 13

pathway between abdominal wall muscles and their aponeuroses

Question 14

What forms the rectus sheath? Where are they?

Answer 14

formed by the aponeuroses of the EAO, IAO, TA surrounding the RA

external - superficial RA
internal - deep RA

Question 15

What is the clinical importance of the external rectus sheath?

Answer 15

strongest suture holding layer when closing a paramedian incision

Question 16

What is the linea alba?

Answer 16

ventral midline junction of rectus sheaths that extends from xiphoid process to pubis

Question 17

What are the features of the linea alba that make it a good choice for abdominal incision?

Answer 17

avascular and no nerves, strong suture properties

Question 18

List the sequential layers for a ventral midline celiotomy

Answer 18

1. skin
2. SQ tissue
3. linea alba
4. retroperitoneal fat
5. peritoneum

Question 19

List the sequential layers of a paramedian incision

Answer 19

1. skin
2. SQ tissues
3. external rectus sheath
4. rectus abdominis
5. internal rectus sheath
6. retroperitoneal fat
7. peritoneum

Question 20

List the sequential layers for a laparotomy

Answer 20

1. skin
2. SQ tissue
3. EAO
4. IAO
5. TA
6. peritoneum

Question 21

When closing, what tissues are considered our strength-holding layers

Answer 21

1. TA/IAO
2. EAO
3. skin
4. maybe SQ layer

Question 22

What are the origins of the external abdominal oblique? Where do the fibers run?

Answer 22

thoracolumbar fascia and lateral surface of ribs

caudoventrally

Question 23

What are the origins of the internal abdominal oblique? Where do the fibers run?

Answer 23

tuber coxae and thoracolumbar fascia

cranioventrally

Question 24

What are the origins of the transversus abdominis? Where do the fibers run?

Answer 24

lumbar transverse processes

dorsoventrally

Question 25

What are the origins of the rectus abdominis? Where do the fibers run?

Answer 25

costal cartilage/sternum and brim of pubis

craniocadually

Question 26

What is unique about the rectus abdominis?

Answer 26

divided into segments by the tendinous inscriptions (6-pack)

Question 27

What is unique about the internal abdominal oblique?

Answer 27

covers paralumbar fossa

Question 28

What is unique about the tranversus abdominis?

Answer 28

spinal nerves on the surface

Question 29

How is the superficial inguinal ring formed

Answer 29

slit in the aponeuroses of the external abdominal oblique

Question 30

what passes through the inguinal canal

Answer 30

external pudendal a/v
genitofemoral n.
spermatic cord
vaginal process

Question 31

how is the deep inguinal ring formed

Answer 31

intersection of the inguinal ligament, caudal border of the IAO, and lateral border of the RA

Question 32

When would we do a paramedian cut versus a ventral midline cut

Answer 32

if the linea alba is infected or if needing access to a particular organ

Question 33

Attachment of:

iliocostalis system

Answer 33

ilium to rib 1

Question 34

Attachment of:

longissimus system

Answer 34

ilium to skull

Question 35

Attachment of:

transversospinalis system

Answer 35

sacrum to skull

Question 36

Attachment of:

semispinalis capitis

Answer 36

thoracic vertebrae to the skull

Question 37

Attachment of:

splenius

Answer 37

spinous processes T1-3 and median raphe to the skull

Question 38

Attachment of:

longus colli

Answer 38

ventral vertebral bodies and transverse processes T6-C1

Question 39

Attachment of:

longus capitis

Answer 39

cervical transverse processes to skull

Question 40

What are the extensors and lateral movers of the vertebral column

Answer 40

iliocostalis, longissimus, and transversospinalis

Question 41

What are the extensors of the head and neck

Answer 41

semispinalis and splenius

Question 42

T/F: splenius and semispinalis secondarily laterally flex the neck

Answer 42

True

Question 43

Action of:

longus colli

Answer 43

flex neck

Question 44

Action of:

longus capitis

Answer 44

flex atlanto-occipital joint
draw neck ventrally