Anterior Abdominal Wall and Inguinal Region Lecture Notes

Flashcards based on lecture notes about the anterior abdominal wall and the inguinal region.

What is the abdomen?

The region of the trunk that lies between the diaphragm (above) and the inlet of the pelvis (below).

What are the boundaries of the abdomen?

Diaphragm, lumbar vertebrae, quadratus lumborum, psoas major & minor, iliacus.

The diaphragm extends superiorly to which intercostal space (ICS)?

Superior extends to ICS-4th.

What is the anterolateral boundary of the abdomen?

Muscles of the anterior abdominal wall.

What is the inferior boundary of the abdomen?

Pelvic Inlet.

What planes define the four quadrants of the abdominal cavity?

Transverse transumbilical plane and vertical median plane.

What are the two horizontal lines used to define the nine regions of the anterior abdominal wall?

Subcostal plane and transtubercular plane.

Which plane passes through the inferior border of the 10th rib?

Subcostal plane

What are the two vertical lines used to define the nine regions of the anterior abdominal wall?

Right and Left Midclavicular lines.

Through what does the transpyloric plane pass?

L1 or the tip of the 9th costal cartilage.

What are the layers of the anterior abdominal wall?

Skin, Fascia, Muscles, Investing Fascia, Fascia Transversalis, Extraperitoneal Fat, Parietal Peritoneum.

What are the two layers of the superficial fascia of the anterior abdominal wall?

Superficial fatty layer (Camper) and deep membranous layer (Scarpa).

What are Langer’s Lines or Cleavage Lines?

Orientation of collagen fibers in the dermis.

What arteries supply the abdominal skin?

Superior Epigastric, Inferior Epigastric, Intercostal, Lumbar, Superficial Circumflex Iliac.

What are the two venous anastomoses of the superficial veins around the umbilicus?

Cavo-caval and Portal-caval.

Where does the lymphatic drainage above the umbilicus drain?

Anterior axillary (pectoral) group of nodes.

Where does the lymphatic drainage below the umbilicus drain?

Superficial inguinal nodes.

What is the nerve supply of the anterior abdominal wall?

Lower six thoracic nerves + L1.

What dermatome supplies the umbilicus?

T10.

Where does the neurovascular bundle of the abdominal wall pass in relation to the abdominal muscles?

Internal oblique and superficial to transversus abdominis.

What does injury to the nerves of the anterolateral abdominal wall result in?

Weakening of the muscles of the anterior abdominal wall.

What can result from a straddle injury?

Rupture of the penile urethra may be followed by extravasation of urine.

What are the muscles of the anterior abdominal wall?

External oblique, internal oblique, transversus abdominis, rectus abdominis, pyramidalis.

What innervates the external oblique?

T7 to T11 thoracic nerves and subcostal nerve.

What is the Inguinal ligament?

Modification of the aponeurosis Ext. Ob. Abdominis muscle. It extends from the anterior superior iliac spine to the pubic tubercle, forming the base of the inguinal canal.

What innervates the internal oblique?

Lower five intercostal nerves and the subcostal nerve. Iliohypogastric and ilioinguinal nerves.

What innervates the transversus abdominis?

Lower five intercostal nerves, subcostal nerve, iliohypogastric and ilioinguinal nerves.

What is the conjoint tendon?

Fusion of inferomedial portion of aponeurosis of internal oblique and transversus abdominis muscles.

What innervates the rectus abdominis?

Lower six or seven thoracic spinal nerves and subcostal nerves.

Why is the rectus abdominis an excellent myocutaneous flap?

Excellent vascularity provided by the epigastric vessels and the muscle belly.

What innervates the pyramidalis?

Terminal branches of the subcostal nerve.

What is the rectus sheath derived from?

Derived from the aponeuroses of flat muscles of the anterior abdominal wall.

What are the contents of the rectus sheath?

Muscles, arteries, veins, nerves.

Source that bleeding come from on a Hematoma of the Rectus Sheath?

Inferior epigastric vein.

Why is a midline incision relatively bloodless?

Small vessels and nerves, bloodless.

What is an incisional hernia?

Omentum or an organ through a surgical incision.

What is congenital umbilical hernia, or exomphalos (omphalocele) caused by?

Failure of part of the midgut to return to the abdominal cavity from the extraembryonic coelom during fetal life.

Where do Spigelian hernias occur?

Along the semilunar lines.

What are the sections of the Inguinal Region?

Inguinal Ligament, inguinal canal, 2 inguinal rings.

Where does the inguinal region extend?

Between the ASIS and pubic tubercle.

Inguinal ligament is modification of which muscle?

EXTERNAL OBLIQUE MUSCLE.

What structure is in the Superficial inguinal ring?

Opening in ext. oblique muscle.

What structure is in the Deep inguinal ring?

Oval opening on the fascia transversalis.

What is the male content of Inguinal canal?

Spermatic cord with its own contents.

What is the female content of Inguinal canal?

Round ligament of the uterus.

What is the content of Both Sexes in Inguinal canal?

ilioinguinal nerve.

layers make up the spermatic cord?

External spermatic fascia, cremasteric fascia, internal spermatic fascia.

Where does INGUINAL HERNIA lie?

Lies above and medial to the pubic tubercle.

Where does FEMORAL HERNIA lie?

Lies below and lateral to the pubic tubercle.

What is the scrotum?

Outpouching of the lower part of the anterior abdominal wall.

What does the scrotum contain?

Testes, Epididymis, Lower ends of the spermatic cords.

What is Fatty layer (Camper) replaced by?

Smooth muscle called the DARTOS MUSCLE.

Where is Internal spermatic fascia derived?

From the fascia transversalis.

What is the action of the cremaster muscle?

Pulls the testis up towards the superficial inguinal ring.

What innervates supplying the anterolateral surface of the scrotum?

Genital branch of the genitofemoral nerve (L1, L2).

Where does Cancer from testis spread to?

Lumbar group=ParaAortic.

What is the Lymphatic drainage of the TESTIS?

Right and left lumbar (cava/aortic) and para-aortic lymph nodes>thoracic lymp.duct.

How does The SKIN and SUBCUTANEOUS TISSUE of the ABDOMINAL WALL wall drain?

Superiorly via the internal thoracic vein medially and the lateral thoracic vein laterally.