Anterior Abdominal Wall

Question 1

What is the peritoneum?

Answer 1

An extensive serous membrane that covers abdominal organs and the wall of the abdominal cavity.

Question 2

Describe the apertures (holes) in the abdominal walls.

Answer 2

Front: umbilical vessels, including the allantois and vitelline duct.
Above: the vena caval opening for the IVC, the aortic hiatus for the aorta, azygous vein, and thoracic duct, and the esophageal hiatus for the esophagus.
Below: two on both sides, one for the femoral vessels and nerve, and the other for the spermatic cord (male) or round ligament of the uterus (female)

Question 3

How are the abdominal quadrants divided?

Answer 3

Vertical line through the midline, horizontal line at the umbilicus

Question 4

How many anatomical regions of the abdomen are there? What are the two usual transverse planes that divide the abdomen?

Answer 4

9, the subcostal plane (at the level of the inferior part of rib 12) and the intertubercular planes divide the abdomen.

Question 5

What will you encounter first when you cut open someone’s abdomen?

Answer 5

Two fascial layers. An outer fatty layer (Camper’s fascia - several cm thick), and an inner membranous layer (Scarpa’s fascia - thin)

Question 6

After you get through the abdominal fascia, what muscles will you encounter (from superficial to deep)? What is deep to these muscles?

Answer 6

Rectus abdominis, external oblique, internal oblique, and transversus abdominus. Deep to these is the transversalis fascia, followed by some extra-peritoneal CT, and finally the innermost lining of the abdominal cavity is the peritoneum.

Question 7

What happens to Camper’s fascia and Scarpa’s fascia as they travel inferiorly?

Answer 7

Camper’s fascia continues from the abdomen onto the fatty layer of the thigh; Scarpa’s fascia is attached to the iliac crest and the fascia lata approximately 2-3 cm inferior to the inguinal ligament.

Question 8

What happens to Scarpa’s fascia as it passes into the scrotum?

Answer 8

It becomes Colle’s fascia

Question 9

What happens to Camper’s fascia as it passes into the scrotum?

Answer 9

It loses fat, gains smooth muscle and is called the Tunica Dartos aka Dartos fascia. This is responsible for wrinkled balls in the cold.

Question 10

What does Scarpa’s fascia do in the pubic region?

Answer 10

It contributes fibers to the suspensory ligament of the penis, the fundiform ligament.

Question 11

The linea alba is a midline tendinous band which runs from the ________ ________ to the _______. The aponeuroses of the three flat abdominal muscles contribute to its formation.

Answer 11

xyphoid process to the pubis

Question 12

Where does the external oblique muscle originate from? Where does it insert?

Answer 12

Originates from the external surface and inferior border of ribs 5-12 (upper fibers join with the serratus anterior and lower fibers join with the latissimus dorsi).

Lowest fibers insert onto the anterior half of the iliac crest and the remaining ones terminate onto a broad aponeurosis which inserts into the midline linea alba, the inguinal ligament, and onto the pubic tubercle.

Question 13

What forms the superficial inguinal ring?

Answer 13

The termination of the external oblique at the pubic tubercle.

Question 14

What is the definition of an aponeurosis?

Answer 14

layers of broad, flat tendons.

Question 15

Through what structure does the spermatic cord travel to the scrotum from the abdomen?

Answer 15

Through the inguinal canal

Question 16

As the spermatic cord passes under the external oblique and through the ring, it carries with it some of the fibers of the external oblique muscle. These fibers become the ________ _______ _______ of the spermatic cord.

Answer 16

external spermatic fascia

Question 17

What forms the inguinal ligament? What structures does it connect?

Answer 17

Lower aponeurotic fibers of the external oblique. It spans the ASIS and pubic tubercle.

Question 18

Name the origin and insertion of the internal oblique muscle.

Answer 18

Origin is the lateral half of the inguinal ligament and from the anterior 2/3 of the iliac crest. The internal oblique inserts onto the inferior borders and cartilages of ribs 9-12 and into a broad aponeurosis medially.

Question 19

What happens to the internal and external oblique muscles at the semilunar line (the lateral border of the rectus abdominis muscle)?

Answer 19

Their respective aponeuroses fuse to form the rectus sheath.

Question 20

What forms the posterior (dorsal) rectus sheath?

Answer 20

The aponeuroses of half of the internal oblique and all of the transversus abdominis (superior to the arcuate line)

Question 21

Somewhere between the umbilicus and the pubis the internal oblique aponeurosis is no longer split and the aponeurosis passes anterior to the rectus abdominis muscle. There the internal oblique contributes only to the ______ _______ sheath.

Answer 21

anterior rectus

Question 22

What tendon is formed by the joining of the medial fibers of the internal oblique aponeurosis and the underlying fibers of the transversus abdominis aponeurosis?

Answer 22

The conjoint tendon aka falx inguinalis

Question 23

What is the middle fascial layer of the spermatic cord called? From what is this layer derived?

Answer 23

The cremaster fascia, derived from the internal oblique muscle.

Question 24

What does the cremaster muscle do? What nerves are responsible? What spinal segments are involved? What is this called?

Answer 24

Raises the testes superiorly towards the superficial inguinal ring.

When the superior medial thigh is “stroked,” the ilioinguinal nerve sends the afferent signal and the genitofemoral nerve is the motor efferent to the cremaster muscle. Involves L1 and L2 spinal segments. This is called the cremasteric reflex.

Question 25

The inferior aponeurosis of the transversus muscle joins with the aponeurosis of the internal oblique muscle to form the _______ tendon just lateral to the pubic symphysis.

Answer 25

conjoint

Question 26

What is the arcuate line?

Answer 26

The place where the aponeuroses of the obliques and transversus abdominis muscle change the way that they wrap around the rectus abdominis:

Superior to the arcuate line, the aponeurosis of the transversus abdominis and half of the aponeurosis of the internal oblique runs inside (dorsal side) the rectus abdominis, and the other half of the aponeurosis of the internal oblique + the external oblique aponeurosis runs outside (ventral side) the rectus abdominis.

Inferior to the arcuate line, they switch and all run outside the rectus abdominis.

Question 27

What three nerves innervate the three flat muscles of the anterior abdominal wall (transversus, internal and external obliques)?

Answer 27

Intercostal nerves 7-12, the ilio-hypogastric nerve, and the ilioinguinal nerve.

Question 28

From what does the rectus abdominis muscle originate? Where does it insert? What separates it at the midline?

Answer 28

Originates from the pubic crest (medial to the pubic tubercle).

Inserts on to costal cartilages of ribs 5-7 and on to the sides of the xyphoid process.

Separated along the midline by the linea alba.

Question 29

What is the action of the rectus abdominis mucle? What is its innervation?

Answer 29

Flexes the vertebral column and tenses the abdomen. Innervated by intercostal nerves 7-12

Question 30

The aponeuroses from three muscles combine to form the rectus sheath. Which muscles are they?

Answer 30

Internal, external obliques and transversus abdominis muscles.

Question 31

What are the lateral borders of the rectus abdominis muscle called?

Answer 31

Linea semilunaris

Question 32

What forms the internal spermatic fascia?

Answer 32

Parts of the transversalis fascia that travel with the spermatic cord as it goes through the deep inguinal ring

Question 33

There is a weakening in the abdominal wall at the area of the ______ ______ _____, which is the same place where the spermatic cord leaves the abdominal cavity.

Answer 33

deep inguinal ring

Question 34

Name the layers seen in a cross-section of the spermatic cord (8).

Answer 34

1. external spermatic fascia
2. cremasteric muscle and fascia
3. genitofemoral nerve
4. internal spermatic fascia
5. ductus deferens
6. lymph vessels
7. pampiniform plexus of veins, which will become the testicular vein.
8. testicular artery

Question 35

Name the three fascial layers of the spermatic cord and from where each layer was derived.

Answer 35

Internal spermatic fascia - derived from the transversalis fascia.

Middle is the Cremaster fascia - derived from the internal oblique muscle.

External spermatic fascia - derived from the external oblique muscle.

Question 36

The _______ _______, a double serous membrane derived embryologically from the peritoneum during the descent of the testis from the abdominal region to the scrotum, surrounds the testis anteriorly and laterally.

Answer 36

tunica vaginalis

Question 37

Are the epididymis and vas deferens surrounded by the fascias of the spermatic cord?

Answer 37

Yeah

Question 38

What supplies blood to the testis?

Answer 38

Testicular artery

Question 39

What is the gubernaculum testis? What is the equivalent of this structure in the female?

Answer 39

The fetal ligament that connects to the testis during fetal development. Its equivalent to the round ligament of the uterus.

Question 40

What is a hydrocele? What is a hematocele? What causes these?

Answer 40

Accumulation of fluid or blood in the cavity of the tunica vaginalis or along the spermatic cord. May result from infection or injury to the testis that causes the tunica vaginalis to secrete fluid.

Question 41

What is a varicocele? What causes it? What is the treatment?

Answer 41

Varicose veins in the pampiniform plexus of the spermatic cord. With static flow, they are unable to cool the testis –> low sperm count or infertility. Common on the left side possibly as a result of a malignant tumor of the left kidney that blocks the exit of the left testicular vein. Tx is surgery to remove the varicose veins.

Question 42

What is a vasectomy?

Answer 42

Surgical excision of a portion of the vas deferens through the scrotum. It stops the passage of sperm but neither reduces the amount of ejaculate greatly nor diminishes sexual desire.

Question 43

What is testicular torsion? What causes it? What is the treatment?

Answer 43

Twisting of the spermatic cord and testis in the scrotum. Caused by trauma or spasm of the cremaster muscle. Tx is surgery.

Question 44

True or false: Testicular cancer can arise from spermatogenic cells, sertoli cells, or leydig cells and arises as a painless lump, testicular swelling, and a feeling of heaviness or aching in the scrotum or lower abdomen.

Answer 44

true

Question 45

If looking from the inside of the abdominal wall at the anterolateral aspect of the wall, one will see five ridges. What do these correspond to?

Answer 45

1. The median umbilical fold - contains the urachus, a fibrous remnant of the allantois, a canal that drains the urinary bladder of the fetus.

2, 3. The medial umbilical folds - enclose the obliterated fetal umbilical arteries.

4, 5. The lateral umbilical folds - enclose the inferior epigastric vessels.

Question 46

The superficial arteries of the abdomen include the superficial inferior epigastric vessels, the circumflex iliac vessels, and the external pudendal vessels, which arise from the ________ artery near the inguinal ligament. These empty into the _________ vein by passing through the saphenous opening.

Answer 46

femoral artery, femoral vein

Question 47

Name the deep vessels of the abdomen.

Answer 47

Superior and inferior epigastric vessels, the deep iliac circumflex vessels, and the testicular vessels.

Question 48

Where does the cremasteric artery come from? What does it supply?

Answer 48

The inferior epigastric artery. Supplies the cremaster muscle.

Question 49

From what does the superior epigastric artery arise from?

Answer 49

The internal thoracic artery

Question 50

What does the testicular artery arise from?

Answer 50

Anterior aorta

Question 51

Which lymph nodes receive lymph for superficial drainage above the umbilicus?

Answer 51

Axillary nodes

Question 52

Where does testicular lymph drainage go?

Answer 52

To the para-aortic nodes –> cysterna chyli

Question 53

Which areas drain lymph to the superficial inguinal nodes (3)?

Answer 53

1. Butt
2. External third of the anal canal
3. External sex organs

Question 54

Where does deep abdominal lymph drainage go?

Answer 54

Lateral (para-aortic) nodes –> cysternal chyli

Question 55

Inguinal hernias may damage the _______ _______ due to compression. Resultant infarction may result in gangrene of downstream structures.

Answer 55

spermatic cord

Question 56

Describe an indirect inguinal hernia.

Answer 56

Passage of the hernial sac through the deep inguinal ring, through the inguinal canal, and out the superficial inguinal ring.

Question 57

Describe the location of the neck of an indirect inguinal hernia with respect to the inguinal ligament and deep inferior epigastric vessels.

Answer 57

The neck of the hernia will lie above the inguinal ligament and lateral to the deep inferior epigastric vessels.

Question 58

Which type of hernia is most common?

Answer 58

Indirect inguinal hernia

Question 59

What developmental structure is likely responsible for the high incidence of indirect inguinal hernias?

Answer 59

The patent processus vaginalis (an embryonic outpouching of the peritoneum)

Question 60

Direct inguinal hernias, also common, occur primarily in people aged _____ to _____, and frequently _______ into the abdomen when the patient is lying down. They are frequently _________. They occur because of a congenital defect in the _______ _______.

Answer 60

40-50 years old, retracts into the abdomen when lying, frequently asymptomatic. Defect is in the conjoint tendon.

Question 61

Describe the location of the neck of a direct inguinal hernia with respect to the inguinal ligament and deep inferior epigastric vessels.

Answer 61

Above the inguinal ligament and MEDIAL to the deep epigastric vessels in Hesselbach’s triangle.

Note the indirect hernia is also above the inguinal ligament but LATERAL to the deep epigastric vessels.

Question 62

What is the difference between a femoral hernia and an inguinal hernia? Through what structures do femoral hernias travel?

Answer 62

Femoral hernias are BELOW the inguinal ligament. They travel through the femoral ring into the femoral canal.

Question 63

Which hernia is more common in females?

Answer 63

Femoral hernias

Question 64

Compare femoral hernias and inguinal hernias with their locations respective of the pubic tubercle.

Answer 64

Femoral hernias will be seen inferior and lateral to the pubic tubercle, while inguinal hernias will be found superior and medial to the pubic tubercle

Question 65

Lumbar hernias occur through the ________ ________, an area superior to the middle iliac crest, which is covered only by the transversus abdominis muscle and the internal oblique muscle. This area is also known as _____ triangle.

Answer 65

occurs through the lumbar triangle.

Petit’s triangle

Question 66

Name three hernias seen more often in early life. Hernias in these areas are likely to contain _______.

Answer 66

1. Umbilical hernia
2. Paraumbilical hernia - linea alba
3. Spigelian hernia - linea semilunaris

likely to contain omentum (a layer of peritoneum that surrounds abdominal organs)

Question 67

What are the boundaries of Hesselbach’s triangle? What is the clinical significance of this triangle?

Answer 67

Anterior abdominal structures form the boundaries: lateral boundary is the inferior epigastric vessels, medial boundary is the lateral border of the abdominis rectus, and inferior boundary is the inguinal ligament.

DIRECT inguinal hernias travel through the triangle and through the inguinal canal.