Sem 1 - H -Antero-Lateral Abdominal Wall - quadrants/regions, layers, fascia, muscles, blood/nerve supply, lymphatics

Question 1

What line and at what level separates the superior and inferior mediastinum?

Answer 1

Superior mediastinum is separated from the inferior mediastinum by the transverse thoracic plane at the T4/5 intervetebral disc

Question 2

The abdomen can be split into four quadrants, the right and left, upper and lower quadrants Which two lines separate the abdomen into these 4 quadrants?

Answer 2

The median plane - runs through the umbilicus The trans-umbilical plane - runs between L3/4 IV disc

Question 3

As said, there are 4 regions of the abdominal cavity separated by the median plane and trans-umbilical plane (L3/4 IV disc) The abdomen can also be split into 9 regions What are these 9 regions?

Answer 3

Right and left hypochodnrium Epigstric Right and left lumbar (flank) Umbilical Right and left iliac fossa Suprapibic (hypogastric)

Question 4

What lines separate the regions of the abdomen into 9?

Answer 4

Vertical line - mid clavicular plane Horizontal lines - subcostal and trans-tubercular plane

Question 5

Where does the midclavicular plane run from? Where does the subcostal and trans-tubercular planes run from?

Answer 5

Midclavicular plane - from midpoint on the clavicle to midpoint on the inguinal ligamen t Subcostal plane - from most inferior point of costal margin - the 10th costal cartilage Trans-tubercular plane - horizontally connects tubercles of the iliac crest - L5 vertebral level

Question 6

What are the layers of the antero-lateral abdominal wall between the skin and the parietal peritoneum?

Answer 6

Skin Superfical fascia Muscle + deep fascia Extra-peritoneal fascia Parietal peritoneum

Question 7

What are the white lines in this image between the external, internal oblique and transversus abdominus?

Answer 7

These are the (supericial, intermediate and deep) investing deep fascia between the anterolateral abdominal wall muscles

Question 8

Above umbilicus the superficial fascia is similar to that found elsewhere in the body What is the difference in the superficial fascia below the umbilicus?

Answer 8

The superficial fascia is split into two layers below the umbilicus We have the superficial (fatty) layer - Camper’s fascia and We have the deep (membranous) layer - Scarpa’s fascia

Question 9

What is Camper’s fascia?

Answer 9

This is a superfical fatty layer of subcutenous tissue of varying thickness

Question 10

Camper’s fascia is continuous over the inguinal ligament and into the fascia of the thigh and perineum What does the carpa’s fascia become in the male and female genitalia?

Answer 10

In males, camper’s facia continues into the fascia of the penis. It loses its fatty layer and fuses with the deeper layer of superficial fascia to become the dartos fascia of the scrotum In females, it retains its fatty layer and contributes to the fascia of the labia majora

Question 11

What is Scarpa’s fascia and where does it attach to? What does it fuse with below the inguinal ligament?

Answer 11

Scarpa’s fascia is thin and membranous with very little fat It is attached to the pubic symphysis and line alba in the midline Below the inguinal ligament it fuses with the fascia of the thigh to form the tensor fascia lata

Question 12

Scarpa’s fascia is the thin membranous deep layer of the superifical tissue of the anterolateral abdominal wall What does it fuse/continue with below the inguinal ligament/in male and female genitalia?

Answer 12

Below inguinal ligament fuses with the fascia of the thigh to form the fascia lata Attaches to the posterior part of the perinal membrane forming the superifical perinal membrane Males - continuous with fascia of penis, dartos fascia of scrotum, fundiform ligament of the penis In females - contributes to the labia majort

Question 13

Describe in full, what camper’s fascia is and what its perineal structure continuations are in both male and female? Does the Camper’s fascia retain or lose its fatty layer once continuing into the genitalia of males an females?

Answer 13

Camper’s fascia - superficial fatty layer of superficial fascia of below the umbilicus - continuous over the inguinal ligament into fascia of the thigh and perineum * Males - continuous into fascia of penis losing its fatty tissue and fuses with deeper layer of superficial fascia to become dartos fascia of scrotum * Females - retains fatty layer - contributes to fascia of labia majora

Question 14

Describe in full, what Scarpa’s fascia is and what its perineal structure continuations are in both male and female?

Answer 14

Scarpa’s fascia - thin membranous deep layer of superficial fascia with little fat - below inguinal ligament fuses with fascia of thigh to form fascia lata Attaches to the pubic symphysis and linea alba medially Attaches to the posterior part of the perineal membrane (superficial fascial layer of the urogenital diaphragm) * In males - continous with fascia of penis, dartos fascia of scrotum, fundiform ligament of penis * In females- contributes to the labia majora

Question 15

What is the fundiform ligament of the penis? What does it unite with inferiorly to form the scrotal septum?

Answer 15

This is a specialised thickening of the Scarpa’s fascia extending from the linea alba of the abdomen The ligaments splits to surround the penis laterally at its base and unites inferiorly with the dartos fascia forming the scortal septum

Question 16

What are the anterolateral abdominal wall muscles and what is there overall function?

Answer 16

These are the: External oblique Internal oblique Transversus abdominus Rectus abdominus They serve to support the abdominal contents in addition to individual movements

Question 17

What direction do the fibres of the external obliques run? Where does the external oblqique run from? Where does the aponeurosis of the external oblqiue run from?

Answer 17

External oblique fibres run in an infero-medial direction from ribs 5-12 to the iliac crest and linea alba The aponeurosis –> the linea alba running from xiphoid process to pubic symphysis

Question 18

What movement does contraction of the external obliques permit and what is its nerve supply?

Answer 18

Bilateral contraction flexes the trunk, unilateral contraction will rotate the trunk to the same side Nerve supply - anterior rami of T7-T12

Question 19

• What direction do the fibres of the external obliques run?
• Where does the external oblqique run from?
• Where does the aponeurosis of the external oblqiue run from?
• What movement does contraction of the external obliques permit and what is its nerve supply?
• What does the lower border of the external oblique aponeurosis form?

Answer 19

• Runs in an infero-medial direction from ribs 5-12 to linea alba and iliac crest
• Aponeuorsis - linea alba from xiphoid process to pubic sympyshis
• Bilateral contraction flexes trunk, unilateral rotates trunk to the same side
• Nerve innervation - T7-T12
• Lower border forms inguinal ligament

Question 20

What direction do the fibres of the internal obliques run? Where do the internal oblique fibres run from? Where does the aponeurosis of the internal oblqiue end in?

Answer 20

The internal oblqiue is deeper smaller and thinner than the external oblique Fibres run in a supero-medial direction from the thoracolumbar fascia, inguinal ligament and iliac crests to ribs 9-12 The internal oblique aponeurosis ends in the linea alba, pectineal line, pubic crest

Question 21

What movement does contraction of the internal obliques permit and what is its nerve supply?

Answer 21

Bilateral contraction of internal oblique flexes trunks, unilateral contraction bends trunk laterally Nerve supply - anterior rami of T7-12 and L1

Question 22

What direction do the fibres of the internal obliques run? Where do the internal oblique fibres run from? Where does the aponeurosis of the internal oblqiue end in? What movement does contraction of the internal obliques permit and what is its nerve supply?

Answer 22

Runs in a supero-medial direction from the thoracolumbar fascia, inguinal ligaments and iliac crest to ribs 9-12 Aponeurosis ends in linea alba, pectineal line and pubic crests Bilateral contraction - flexion of trunk, unilateral - lateral flexion Nerve innervation - anterior rami T7-12 and L1

Question 23

Transversus abdominus is deep to the internal oblique What direction do the fibres run? What is the function of the fibres?

Answer 23

The transversus abdominus fibres run in a horizontal direction (transverse) with the function of supporting the body wall

Question 24

Where does the transversus abdominus run from and what is its nerve supply?

Answer 24

Runs from thoracolumbar fascia, iliac crest, inguinal ligament and costal cartilages of ribs 7-12 to the linea albea, pectineal line and pubic crest Nerve innervation - anterior rami T7-L1

Question 25

Transversus abdominus is deep to the internal oblique What direction do the fibres run? What is the function of the fibres? Where does the transversus abdominus run from and what is its nerve supply?

Answer 25

Transversus abdominus fibres run in a transverse direction and support the body wall Fibres run from thoracolumbar fascia, iliac crests, inguinal ligament and costal cartilages T7-12 to linea albea, pectineal line and pubic crests Nerve innervation - Anterior rami T7-L1

Question 26

What direction do the fibres of the rectus abdominus run? Where do the rectus abdominus fibres run from?

Answer 26

Rectus abdominus fibres run superiorly from pubic tubercle, crest and symphysis to xiphoid process and costal cartilage of ribs 5-7

Question 27

What is the function of the rectus abdominus and what is the nerve innervation?

Answer 27

Contraction of rectus abominus flexes the trunk, also supports/compresses abdominal wall Nerve innervation T7-T12

Question 28

What direction do the fibres of the rectus abdominus run? Where do the rectus abdominus fibres run from? What is the function of the rectus abdominus and what is the nerve innervation?

Answer 28

Fibres run superiorly from pubic crest, tubercle and symphysis to xiphoid process and costal cartilage of ribs 5-7 Function - flexes trunk, supports/compresses abdominal wall Nerve innervation - T7-T12

Question 29

What is the pyramidalis muscle? Where does it attach? What its its function? What is it nerve supply?

Answer 29

The pyramidalis muscle is a small triangular muscle sitting anterior to the rectus abdominus but contained within the rectus sheath It attaches from pubis to linea alba and tenses the linea alba Nerve supply - anterior rami T12

Question 30

What forms the rectus sheath?

Answer 30

The rectus sheath is formed by the aponeurosis of the external oblique, internal oblique and transversus abdominus

Question 31

What line separates the way in which the rectus sheath surrounds the rectus abdominus? What changes?

Answer 31

~ halfway between the umbilicus and pubic bones is an arch of fascia known as the arcuate line - Above this line, the rectus sheath runs anterior (external & internal oblique aponeurosis) and posteriorly (internal oblique and transversus abdominus aponeurosis) Below the arcuate line the rectus sheath only lies anteriorly - all aponeurosis are anterior

Question 32

Therefore when below the arcuate line, what does the posterior aspect of the rectus abdominus lie on?

Answer 32

The posterior aspect of the rectus abdominus will be in direct contact with the transversalis fascia

Question 33

What lies deep to the transversalis fascia?

Answer 33

Deep to the tranversalis fascia is a layer of extraperitoneal fat - below this is the parietal peritoneum

Question 34

On the posterior surface of the anterior abdominal wall there are three folds, what are these three folds?

Answer 34

* Median umbilical fold (containing median umbilical ligament) * Medial umbilical fold (containing medial umbilical ligament) * Lateral umbilical fold

Question 35

What is the purpose of each of the: Median umbilical ligament? Medial umbilical ligament? Lateral umbilical fold?

Answer 35

Median umbilical ligament is the remnant of the urachus (drained the feotal bladder) Medial umbilical ligament - remnant of the umbilical arteries Lateral umbilical fold - contains the inferior epigastric vessels

Question 36

What are the superficial nerves of the anterolateral abdominal wall?

Answer 36

Lateral cutenous branches of 6-12 intercostal nerves and iliophypogastric nerve (L1) Anterior cutaneous branches of 6-12 intercostal nerves

Question 37

What are the superficial arteries of the anterior abdominal wall?

Answer 37

Musculophrenic branch of the internal thoracic artery Superficial epigastric and superficial circumflex iliac branches of femoral artery

Question 38

What arteries does the main blood supply to the anterolateral abdominal wall come from? (the supericial arteries mainly supply skin - musculophrenic branch of internal thoracic, superficial epigastric and superficial circumflex iliac artery branches of femoral artery)

Answer 38

Anterior abdominal wall - superior epigastric artery, direct continuation of the internal thoracic artery, inferior epigastric artery (branch of the external iliac artery) Lateral abdominal wall - mainy intercostal arteries, lumbar arteries and deep circumflex iliac artery

Question 39

The intercostal and subcostal arteries travel within neurovascular bundles, between which muscles? Do the superior and inferior epigastric arteries run anterior or posterior to the rectus abdominus?

Answer 39

Intercostal and subcostal arteries travel within NVB running between internal oblique and transversus abdominus muscles Superior and inferior epigastric arteries run posterior to rectus abdominus

Question 40

What is the nerve supply of the anterolateral abdominal wall? What do the two nerves coming from L1 anterior rami pierce?

Answer 40

Skin+muscle+parietal peritoneum supplied by T7-T11, T12 (subcostal) and L1 (iliohypogastric and ilioinguinal nerves) All anterior rami Iliohypogastric and ilioinguinal are the two L1 anterior rami nerves- they pierce the transversus abdominus muscle

Question 41

External oblique - anterior rami T7-T12 Internal obique and tranvsersus abdominus - anterior rami T7-L1 Is the L1 nerve supplying these two muscles, iliophyogastric or ilioinguinal? Deep lymphatic drainage via internal thoracic artery to which nodes? via abdominal aorta to which nodes? and via external iliac artery to which nodes?

Answer 41

Iliohypogastric and ilioinguinal is the nerve which contributes to supply of the internal oblique and transversus abdominus Deep lymphatic drainage via * internal thoracic artery to parasternal nodes * abdomina aorta to lumbar nodes * externeal iliac artery to external iliac nodes (then to lumbar)

Question 42

As said, lymph from the deep anterior abdominal wall drains to the: * Parasternal nodes via the internal thoracic artery * The lumbar nodes via the abdominal aorta * The external iliac nodes via the external iliac artery * Where does lymph in the superficial anterior abdominal wall drain to? * What is the superficial venous drainage from the anterolateral body wall?

Answer 42

Lymph in the superifical abdominal wall ABOVE the level of the umbilicus drains to the AXILLARY nodes Lymph in the superficial abdominal wall BELOW the level of the umbilicus drains to the SUPERFICIAL INGUINAL nodes The thoracoepigastric and the superficial epigastric veins