1. Anterior abdominal wall

Question 1

What are the muscles of the anterior abdominal wall?

Answer 1

External oblique
Internal oblique
Transverse abdominis
Rectus abdominis

Question 2

In what direction does the external oblique muscle run?

Answer 2

Hands in pockets direction

Question 3

In what direction does the internal oblique muscle run?

Answer 3

Hands outwards direction (opposite to the hands in pockets and the external oblique direction)

Question 4

In what direction does the transverse abdominis muscle run?

Answer 4

Horizontally with some of the most superior parts running upwards and some of the most inferior parts running downwards

Question 5

In what direction does the rectus abdominis run?

Describe the structure and layout of this muscle

Answer 5

Two strips of muscle either side of the umbilicus
Runs vertically downwards
Within the rectus sheath (formed by the aponeurosis of the abdominal muscles)
Tendinous intersections cut through here horizontally to form the six pack
Running with this through the sheath are the epigastric vessels

Question 6

What is the arcuate line of the abdomen?

Answer 6

Aka. The douglas line
Horizontal line along the rectus abdominis separating the inferior and superior portions
This is the point at which the inferior epigastric vessels perforate the rectus abdominis SO above arcuate line, the vessels are outside of the sheath and below the arcuate the line, the vessels are inside the sheath

Question 7

Where do the epigastric arteries come from?

Answer 7

Superior epigastric artery - from the internal thoracic artery
Inferior epigastric artery - from the external iliac artery

Question 8

What is McBurney’s point?

What is this a landmark for?

Answer 8

This is one third of the way between the ASIS and the umbilicus (closest to the ASIS)
This is where you would fine the appendix

Question 9

What is the inguinal ligament?

Answer 9

This is a band running from the pubic tubercle to the ASIS

Question 10

How is the inguinal ligament formed?

Answer 10

From the free border of the aponeurosis of the external oblique muscle
The free border rolls up on itself and this is the inguinal ligament

Question 11

What is the inguinal canal?

Answer 11

Short passage within the anterior abdominal wall

Acts as a pathway for structures to pass from the abdominal wall to the external genitalia

Question 12

Where is the inguinal canal located?

Answer 12

Just superior and parallel to the inguinal ligament

Question 13

What lies in the inguinal canal?

Answer 13

The ilioinguinal nerve is in the inguinal canal
In men, the spermatic cord is also in the inguinal canal
In women, the round ligament of the uterus is in the inguinal canal

Question 14

Where do the testes develop and where do they descend to?

Answer 14

Originate just next to the kidneys in the posterior abdominal wall SO they are a retroperitoneal structure
Then descend down to the scrotum

Question 15

What forms from the descent of the testes?

Answer 15

As the testes descends, it pushes past the anterior abdominal wall and hence the three layers of this wall descends down below with the testes - this then forms the spermatic cord

Question 16

What is the tunica vaginalis and where does it come from?

Answer 16

This is the pouch of serous membrane that covers the testes

Derived from the peritoneum of the anterior abdominal wall

Question 17

What is the relevance of the testes to the inguinal canal

Answer 17

The testes travel through the inguinal canal from the posterior abdominal wall to the anterior abdominal wall - i.e. from the deep inguinal ring to the superficial inguinal ring

Question 18

What is the cremaster muscle?

Answer 18

This is the muscle of the spermatic cord

The muscle by which the testicle can be partially raised

Question 19

Give the reflex of the cremaster muscle

Answer 19

The cremaster reflex causes slight raising of the testicles when the femoral region of the thigh is lightly stroked
Innervation via the genitofemoral nerve

Question 20

Briefly describe the genitofemoral nerve

Answer 20

L1 and L2
Innervates the cremaster and the Dartos muscle 
Two components of the nerve
Genito branch - motor branch 
Femoral branch - sensory to the skin

Question 21

What is the conjoint tendon?

Answer 21

This is where the joint aponeurosis of the internal oblique and the transverse abdomonis muscle inserts into the crest of the pubis, just behind the superficial inguinal ring
At this point, it joins with the tendon of the internal oblique muscle

Question 22

What parts of the anterior abdominal wall surround the spermatic cord?

What else travels with the spermatic cord?

Answer 22

Transversalis fascia (innermost)
Internal oblique muscle
External oblique aponeurosis
Superficial fascia (outermost)
The spermatic cord moves medially towards the testes

Spermatic cord travels with the lymphatics, the arterial supply and the venous drainage etc

Question 23

What is the Dartos muscle and what is it’s function?

Answer 23

Muscle that surrounds the outer part of the testes
Innervated by the genitofemoral nerve
Results in the ruggae that are around the testes
Mainly functions to regulate the temperature

Question 24

What should you remember about the lymphatic drainage of the scrotum/testes?

Answer 24

Lymphatic drainage of the scrotum and the testes are different to each other!!!!

Question 25

What is a hernia?

Answer 25

This is a weakness or a hole in an anatomical structure (e.g. anterior abdominal wall) which allows something to protrude through

Question 26

Is a hernia dangerous?

Answer 26

A hernia by itself is usually harmless but if too much of the abdominal contents passes through the hernia then it can become strangulated
I.e. there is too much in too tight a space and so the blood supply is cut off and this can become ischemic and necrotic - this is a medical emergency

Question 27

What are the different types of hernias that can occur?

Answer 27

Abdominal wall hernias - femoral below inguinal ligament, umbilica, lumbar, hiatal

Inguinal hernias - a hernia that passes through the inguinal canal for a variable distance and exits through the superficial inguinal ring

Question 28

What factors can contribute the formation or worsening of a hernia and why?

Answer 28

Any condition that increases the pressure of the abdominal cavity many contribute to this e.g.:
Obesity
Heavy lifting
Coughing
Straining during bowel movement or urination
Chronic lung disease
Fluid in the abdominal cavity 
Hereditary

Question 29

What is the difference between a direct and an indirect inguinal hernia?

Answer 29

Direct hernia - occurs through a weak point in the fascia of the abdominal wall

Indirect hernia - congenital hernia occurring due to failure of embryonic closure of the deep inguinal ring after the testicle passes through it
Indirect hernia protrudes through the superficial inguinal ring

Question 30

Describe direct inguinal hernias

Answer 30

These are acquired and are associated with older age
Occur in a region where the anterior abdominal wall is naturally weaker - this region is called the inguinal/Hassleback’s triangle
Passes medially to the inferior epigastric artery

Question 31

Describe indirect inguinal hernias

Answer 31

These are congenital and are slightly less common than direct
Pass through the inguinal canal i.e. same pathway as the testes during development
Often passes into the scrotum - these are less reducable than direct inguinal hernias
Passes lateral to the inferior epigastric artery
NB. this can be acquired later in life when some of the muscles at the deep inguinal ring are not as strong as they once were

Question 32

Give the borders of Hasselbach’s triangle

Answer 32

Medial border is the lateral border of rectus abdominus
Upper lateral border is the inferior epigastric vessels
Lower lateral border is the inguinal ligmament

Question 33

Why is Hasselbach’s triangle generally weaker?

Answer 33

Because this triangle is an area of the anterior abdominal wall which is covered by fewer layers of muscle - allows for herniation

Question 34

What is a femoral hernia?

Answer 34

This is a weakness where the femoral content passes through the femoral triangle via the femoral canal
Hernia causes a bulge below the inguinal crease in the middle of the thigh

Question 35

Describe femoral hernias and who they are prevalent in

Answer 35

These are rare and usually occur in women - this is because their hips are wider and there is a larger level of space under the inguinal ligament
These hernias are at a particular risk of becoming irreducible and strangulated

Question 36

What is an umbilical hernia?

Answer 36

Common type of hernia
Often noted at birth as a protrusion of the bellybutton
Caused when an opening in the abdominal wall doesn’t close properly

Question 37

What is the midpoint of the inguinal ligament?

Answer 37

This is between the ASIS and the pubic tubercle - position of the deep inguinal ring

Question 38

What is the mid-inguinal point?

Answer 38

Halfway between the central line i.e. between the pubic symphysis and the ASIS
This is a good landmark - finger breadth from the deep inguinal ring
Site of the femoral artery (VAN) and femoral pulse