Anterior Abdominal Wall/Inguinal Canal

Question 1

Put the following layers of the anterior abdominal wall in order from superficial to deep

external oblique m, tranversalis fascia, superficial fascia, transversus abdominis, skin, peritoneum, internal oblique m, transversus abdominis, extrapertioneal connective tissue, rectus abdominis

Answer 1

skin
superficial fascia 
external oblique 
internal oblique
rectus abdomis
transversus abdominis
transversalis fascia
extrapertioneal connective tissue
peritoneum

Question 2

OINF

external oblique

Answer 2

origin- external surfaces of ribs 5-12

insertion- linea alba, pubic tubercle, anterior half of iliac crest

nerve- ventral rami of six inferior thoracic nerve

function- compresses and supports abdominal viscera, flexes and rotates trunk

Question 3

OINF

internal oblique

Answer 3

Origin- thoracolumbar fascia, anterior 2/3 of iliac crest, lateral half of inguinal ligament

insertion- inferior borders of ribs 10-12, linea alba, pubis via conjoint tendon

nerve- ventral rami of six inferior thoracic and first lumbar nerves

function: compresses and supports abdominal viscera, flexes and rotates trunk

Question 4

OINF

pyramidalis

Answer 4

origin- body of pubis, anterior to rectus abdominis

insertion- linea alba

nerve- iliohypogastric nerve

function- tenses linea alba

Question 5

OINF

rectus abdominis

Answer 5

origin- pubic symphysis, pubic crest

insertion- xiphoid process, costal cartilages 5-7

nerve- ventral rami of six inferior thoracic nerves

function- flexes trunk, compresses abdominal viscera

Question 6

OINF

transversus abdominis

Answer 6

origin- internal surfaces of costal cartilages 7-12, thoracolumbar fascia, iliac crest, lateral third of inguinal ligament

insertion- linea alba with aponeurosis of internal oblique, pubic crest, and pecten pubis via conjoint tendon

nerve- ventral rami of six inferior thoracic and first lumbar nerves

function- compresses and supports abdominal viscera

Question 7

What is the superficial fatty of superficial fascia called? What is it replaced by? *

Answer 7

Fascia of Camper’s

is replaced by the subcutaneous dartos muscle in the scrotum

Question 8

What is the deep membranous of the superficial fascia called? What is it continuous with? *

Answer 8

Fascia of Scarpa’s

continuous with the fascia of perineum (Colles’ fascia)

Question 9

OINF

cremaster muscle *

Answer 9

origin- derived from the lower arched fibers of internal oblique. the muscle fibers descend on the spermatic cord to form loops around it

inserted in pubic tubercle

nerve- genital branch of genitofemoral nerve

function- suspends the testis and its action is of value in the Cremaster reflex

Question 10

What is the rectus sheath?

Answer 10

it is an aponeurotic sheath formed by the fusion of the aponeuroses of the external oblique, internal oblique, and transverse muscles of the abdomen

Question 11

What are the contents of the rectus sheath? *
2 muscles
2 vessels
nerves

Answer 11

2 muscles- rectus abdomis and pyramidalis

2 vessels- superior and inferior epigastric vessels

lower 6 intercostal nerves

Question 12

Describe the anterior and posterior walls of the sheath above the arcuate line.

Answer 12

anterior layer of sheath- aponeurosis of the external and internal oblique (anterior layer) muscles

posterior layer- aponeuroses of the internal oblique (posterior layer) and transverse abdominis muscles

Question 13

Describe the anterior and posterior layers of the sheath below the arcuate line.

Answer 13

anterior layer of the sheath- aponeuroses of the external oblique, internal oblique, and transverse abdominis m.

posterior layer of the sheath- rectus abdominis is in contact with the transversalis fascia

Question 14

What are the 3 lines that the rectus abdominis is related to? *

Answer 14

linea alba
linea semilunaris
arcuate line

Question 15

Describe linea alba.

Answer 15

a tendinous median raphe between the two rectus abdominis muscles, formed by the fusion of the aponeuroses of the external oblique, internal oblique, and transverse abdominal muscles

Question 16

Describe linea semilunaris and arcuate line.

Answer 16

linea semilunaris- curved line along lateral border of rectus abdominis

arcuate line- crescent shaped line marking the inferior limit of the posterior layer of the rectus sheath. anterior to that line the inferior epigastric artery ascends to enter the sheath

Question 17

When do the testis descend? How do they descend? Where does it descend from and go?

Answer 17

by 26 weeks
they descend retroperitoneally (external to the peritoneum) from the superior lumbar region to the posterior abdominal wall to the deep inguinal rings. It drags its vessels and nerves from the posterior abdominal wall.

Question 18

Describe the gubernaculum testis. What does it do?

Answer 18

is a mesenchymal band extended from the caudal part of testis along the course of its descent (in the inguinal canal) to blend with the scrotal fascia.

forms a path through the anterior abdominal wall for the processus vaginalis to follow during the formation of the inguinal canal. it anchors the testis to the scrotum and guides its descent into the scrotum

Question 19

Describe the processus vaginalis.

Answer 19

It is a diverticulum or outpouching of the peritoneum which develops ventral to the gubernaculum

Question 20

As the testis and ductus deferens descend, they are ensheathed by the fascial extensions of the abdominal wall:

*What does the extension of the transversalis fascia become?
internal oblique muscle?
external oblique aponeurosis?

Answer 20

extension of transversalis fascia becomes internal spermatic fascia

extension of internal oblique muscle becomes cremasteric muscle

extension of external oblique aponeurosis becomes external spermatic fascia

Question 21

Within the scrotum, where does the testis project?

During the perinatal period, what does the connecting stalk of the processus do?

Answer 21

distal end of processus vaginalis

connecting stalk of the processus normally obliterates, forming a serous membrane (tunica vaginalis) which covers front and sides of testis

Question 22

Describe the inguinal canal:

What is it? Where is it?

How long is it? How is it directed?

Where does it begin and terminate?

how would you describe it from inside to out?

Answer 22

it is the oblique passage in the lower part of the anterior abdominal wall just above the medial half of the inguinal ligament

4 cm long, directed downward forwards and medially (like the external oblique) larger in males than females

canal begins at the deep inguinal ring and terminates at the superficial inguinal ring

can be described inside to out- from the deep ring to the superficial ring as this is the pathway of descent of testis

Question 23

What four muscles share in the formation of the inguinal canal?

Answer 23

transversalis fascia, transversus abdominis, internal oblique, external oblique

Question 24

Describe the boundaries of the inguinal canal:

anterior wall
posterior wall
roof
floor

Answer 24

anterior wall- external oblique aponeurosis, internal oblique fibers (lateral 1/3)

posterior wall- transversalis fascia, conjoint tendon (medial 1/3)

roof- arched fibers of internal oblique (low arched) and transversus abdominis (high arched)

floor- inguinal ligament

Question 25

Describe the transveralis fascia:
What does it line?
What does it form?
How is it represented in the scrotum?
What does it have?

Answer 25

lines the inner surface of transversus abdominis m.
forms the posterior wall of canal
represented in scrotum as internal spermatic fascia*
has deep inguinal ring

Question 26

Describe the deep inguinal ring.
Where does it lie?

What does it have in males/females?

Answer 26

it is an oval opening, lies in the transversalis fascia*, just lateral to the inferior epigastric vessels (which share in inguinal triangle)

is found near the midpoint of the inguinal ligament

has spermatic cord in males (or round ligament of uterus in females) and genital branch of gentiofemoral to cremastric muscle are passing through the deep inguinal ring.

Question 27

Describe the boundaries of the Inguinal triangle (Hasselbach’s triangle)
medially
laterally
inferiorly

What is it a common site of?

Answer 27

medially by the linea semilunaris (lateral edge of rectus abdominis)*
laterally by lateral umbilical fold formed by the inferior epigastric vessels*
inferiorly by the inguinal ligament

area of potential weakness and hence is a common site of a direct inguinal hernia *

Question 28

Describe the fibers of the tranversus abdominis.
What forms the conjoint tendon?
What does it form?
Where is it not represented and why?

Answer 28

most are running transverse except for fibers that originate from the inguinal ligament which are High arching fibers

forms the roof of canal

NOT REPRESENTED* in scrotum due to those high arching fibers

Question 29

Describe the internal oblique.

How do the fibers run?
What does it form?
How is it represented in scrotum?

Answer 29

(raise your hand to the sky)
fibers mostly run upward, forward and medially …except those that originate from the inguinal ligament which are low arching fibers

forms roof of canal with tranversus abdominis

lower free arched fibers of internal oblique has a triple relation (anterior, above, and posterior) to the spermatic cord (or round ligament in females)

represented in scrotum as the cremastric muscle *

Question 30

What forms the conjoint tendon?

Answer 30

high arching fibers of transversus abdominis together with the low arching fibers of internal oblique forms the conjoint tendon.

it descends behind the superficial inguinal ring to be attached to the pubic crest and pectineal line
works as a support to the superficial inguinal ring

Question 31

Describe the external oblique.
How does its fibers run?
What does it form?
How is it represented in the scrotum?
What does it have?

Answer 31

(put your hand in your pocket)
fibers run downward forward and medially

forms anterior wall of canal

represented in scrotum as external spermatic fascia *

has the superficial inguinal ring

Question 32

Describe the inguinal ligament.

What is it?
What does it form?
What does it give partial origin to?
What is the lacunar ligament?

Answer 32

it is the lower thickened border of the external oblique which is folded upon itself

forms the floor of inguinal canal

gives partial origin to internal oblique and transversus abdominis (arching fibers)

lacunar ligament- is a triangular posterior extension from the medial end of inguinal ligament

Question 33

Describe the superficial inguinal ring.
What is it?
What is it supported by?
What passes through?
What is not in the canal?

Answer 33

-triangular opening that lies in the external oblique aponeurosis superolateral to the pubic crest. its base is the pubic crest. sides are medial and lateral crura

supported posteriorly by the conjoint tendon

spermatic cord in males (or round ligament of uterus in females) and ilioinguinal nerve are passing through the superficial inguinal ring

iliohypogastric nerve is NOT in the canal*

Question 34

Describe the pathway of the ilioinguinal nerve.

Answer 34

first pierces transversus abdominis to run between it and internal oblique (neurovascular plane) then it pierces the lower part of the internal oblique then enters the canal to exit through the superficial inguinal ring

iliohypogastric nerve is NOT in the canal*

Question 35

Describe the spermatic cord (loves 3)
3 coverings
3 arteries
3 V's
3 nerves

Answer 35

group of structures that meet at deep inguinal ring and transverse the inguinal canal down to the posterior border of testis at the scrotum

3 coverings:
external spermatic fascia- from external oblique m
cremaster muscle and fascia - from internal oblique
internal spermatic fascia- from transversalis fascia

3 arteries:
testicular, cremastric, and artery of vas

3 V’s:
vas deferens, pampiniform Venous plexus, Vestige of processus Vaginalis

3 nerves:
genital branch of genitofemoral nerve, sympathetic plexus around the testicular artery, sympathetic plexus around the artery of vas

Question 36

What is an inguinal hernia?

Answer 36

protrusion of abdominal contents (usually intestine) within a sac of peritoneum into the inguinal region (canal)

it is much more common in males due to their large canal

Question 37

Describe an indirect inguinal hernia.

Where does it descend?
Where does it lie?
Common?
Congenital or acquired?

Answer 37

passes through the deep ring, inguinal canal, and superficial ring*

descends in the scrotum

lies lateral to the inferior epigastric artery*

more common than direct inguinal hernia

congenital, associated with the persistence of processus vaginalis

Question 38

Describe a direct inguinal hernia.

How does it occur?
Does it reach the scrotum?
Where does it lie?
Congenital or acquired?

Answer 38

occurs through a weakened area of the abdominal wall muscles as the hernia pushes its way directly through the posterior wall of inguinal canal (through the inguinal triangle*)

unusual for the direct hernia to reach the scrotum

lies medial to the inferior epigastric artery*

is acquired

Question 39

Umbilical folds (ligaments).

In suprapubic region, the parietal peritoneum is raised into 5 folds* by 5 structures run in the extra peritoneal tissue. Describe them.

Answer 39

median umbilical fold- raised by median umbilical ligament (fibrosed Urachus*) extend from apex of urinary bladder toward the umbilicus

medial umbilical folds (2) - raised by medial umbilical ligaments (the obliterated portion of the umbilical artery*)

lateral umbilical ligaments (2)- fold of peritoneum over inferior epigastric arteries* on their way to rectus sheath