2.1 Surface anatomy2.2 Anterior abdominal wall

Albert van Schoor

GNK 288 (SA4 Anatomy dissection)

Abdomen 1

2.1.1 Surface anatomy

• Identify and name the bony landmarks of the abdomen which are palpable on abdominal examination and state if possible their corresponding vertebral heights on the cadaver, yourself and on a radiograph

• Schematically illustrate and discuss the nine abdominal regions and list which organs lie approximately in each region

2.1.1 Surface Anatomy

• Identify and name in which of the nine surface anatomical regions you would expect to feel tenderness in appendicitis, cholecystitis, gastritis and cystitis

• Identify other surface anatomy lines e.g. transpyloric line, transumbilical line, linea alba and linea semilunaris. You should be able to say how these lines are formed and to discuss the intra-abdominal events occurring on the transpyloric line

2.1.1 Surface anatomy

Referred pain2.1.1 Surface Anatomy

2.1.1 Surface Anatomy

2.1.1 Surface Anatomy

2.1.1 Surface Anatomy

• Transpyloric plane– Hilum of the

kidneys– Pylorus of the

stomach– Body of

pancreas– Fundus of the

gall bladder

2.1.1 Surface Anatomy

2.1.1 Surface Anatomy

• Schematically illustrate and discuss the surface anatomy of the kidneys, ureters and spleen on the posterior abdominal wall [2.5, 2.8]

• Discuss and identify the surface anatomy of the liver [2.4]

• Briefly discuss the surface anatomy of the diaphragm and the vertebral heights of its three major orifices [2.9]

• Identify the various dermatomes of the anterior abdominal wall

• Indicate whether the bladder is an abdominal organ or not. Explain

2.1.1 Surface anatomy

2.1.1 Surface Anatomy

2.2 Anterior abdominal wall

2.2.1 Skin and superficial fascia

2.2.2 Muscles

2.2.3 Transversalis fascia

2.2.4 Peritoneum

2.2.5 Rectus sheath

2.2.6 Inguinal area

2.2.7 Osteology

2.2.1 Skin and superficial fascia

• Identify the fatty superficial layer (Camper's fascia)

• Identify and shortly discuss the membranous superficial layer (Scarpa's fascia) according to its distribution and borders. State what this fascia is called inferior to the superficial inguinal ring

2.2.2 Muscles • Identify and discuss the three major abdominal

muscles as follows: – Major attachments to the following points: Linea

alba, crista iliaca and inguinal ligament where applicable,

– Direction of fibres, – Nerve supply and – Function

• Identify the neurovascular plane• Identify the ilio-inguinal and iliohypogastric

nerves. Also state their origin and area of supply

2.2.2 Muscles

External oblique

Table

Origin Insertion Innervation Function

Muscular slips from the outer surfaces of the lower eight ribs (ribs 5-12)

Lateral lip of iliac crest; aponeurosis ending in midline raphe (linea alba)

Anterior rami of lower six thoracic spinal nerves (T7 to T12)

Compress abdominal contents; both muscles flex trunk; each muscle bends trunk to same side, turning anterior part of abdomen to opposite side

2.2.2 Muscles

Internal oblique

Origin Insertion Innervation Function

Thoracolumbar fascia; iliac crest between origins of external and transversus; lateral two-thirds of inguinal ligament

Inferior border of the lower three or four ribs; aponeurosis ending in linea alba; pubic crest and pectineal line

Anterior rami of lower six thoracic spinal nerves (T7 to T12) and L1

See External Oblique

2.2.2 Muscles

Transverse abdominis

Origin Insertion Innervation Function

Thoracolumbar fascia; medial lip of iliac crest; lateral one-third of inguinal ligament; costal cartilages lower six ribs (ribs 7-12)

Aponeurosis ending in linea alba; pubic crest and pectineal line

Anterior rami of lower six thoracic spinal nerves (T7 to T12) and L1

Compress abdominal contents

Neurovascular plane2.2.2 Muscles

Ant Post

2.2.3 Transversalis fascia

• Identify the transversalis fascia

2.2.4 Peritoneum

• Identify the folds and associated underlying structures of the peritoneum on the posterior aspect of the anterior abdominal wall: [2.3.3] – Plica umbilicalis mediana, – Plica umbilicalis medialis, – Plica umbilicalis lateralis, – Falciform ligament

2.2.5 Rectus sheath

• Identify the rectus sheath and how it is formed on the following levels:– Superior to the arcuate line– Inferior to the arcuate line 

• Identify and briefly discuss rectus abdominis as follows: – major attachments, – nerve supply and – function

• Name and identify the structures on the posterior wall of the rectus sheath

2.2.5 Rectus sheath

Rectus abdominis2.2.5 Rectus sheath

Origin Insertion Innervation Function

Pubic crest, pubic tubercle, and pubic symphysis

Costal cartilages of ribs 5-7; xiphoid process

Anterior rami of lower seven thoracic spinal nerves (T7 to T12)

Compress abdominal contents; flex vertebral column; tense abdominal wall

2.2.6 Inguinal area

• Identify and briefly discuss the inguinal canal as follows: – Surface anatomy, – Borders, – Openings

Inguinal canalSurface anatomy

2.2.6 Inguinal area

Indirect inguinal hernia2.2.6 Inguinal area

Inguinal canalBorders

2.2.6 Inguinal area

491-8

2.2.6 Inguinal area

• Know the positions of the superficial and deep inguinal rings and femoral canal.

• Identify the inguinal ligament and the structures posterior to it from lateral to medial.

Femoral canal2.2.6 Inguinal area

Ant

Post

Femoral hernia2.2.6 Inguinal area

N.A.V.E.L2.2.6 Inguinal area

Contents

• N.A.V.E.L (lat. - med.)– Femoral nerve– Femoral artery– Femoral vein– Empty space (femoral

canal)– Lacunar ligament

NA V E

L

2.2.6 Inguinal area

• List the contents of the spermatic cord. Compare the content in males and females

• Identify the inferior epigastric artery and its relation to the deep inguinal ring

• Identify and list the borders of the inguinal triangle (Hesselbach's triangle)

• Name and identify the inguinal falx (conjoint tendon)

Spermatic cord• 3 Fascia layers

– External spermatic fascia

– Cremasteric fascia

– Internal speratic fascia

• 3 Arteries– Testicular artery

– Cremasteric artery

– Artery to ductus deferens

• 3 Nerves– Genito-femoral nerve

– Ilio-inguinal nerve

– Sympathetic autonomic plexus

• 3 Other structures– Lymphatic vessels

– Ductus deferens

– Pampiniform venous plexus

2.2.6 Inguinal area

Spermatic cord2.2.6 Inguinal area

Hesselbach’s triangle2.2.6 Inguinal area

Direct inguinal hernia2.2.6 Inguinal area

Conjoint tendon2.2.6 Inguinal area

2.2.7 Osteology

• Identify the following bony points of the os coxa:– Anterior superior iliac spine (ASIS)– Anterior inferior iliac spine (AIIS)– Crista iliaca– Posterior superior iliac spine (PIIS)– Pubic tubercle– Pubic crest– Symphysis pubis

2.2.7 Osteology