Anterior Abdominal Wall anatomy Flashcards
What is the umbilical dermatome root?
T10
What is the inter tubercular plane and where is it located?
Found at L5
Line that crosses horizontally separating the umbilical quadrant from hypogastric quadrant
What is the interspinous plane?
Horizontal line between the ASIS
Found at S1
What is the Supracristal plane and what is its clinical significance?
The highest point of Iliac crest, found at L4
This is the level of Lumber punctures
At what spinal level is the transpyloric plane found?
L1
What is the name of the plane at the level of L3?
Subcostal plane
Lower border of the 12th rib separating the epigastric region from umbilical region
If entering the abdomen laterally, what structures will you encounter, from superficial to deep?
Skin - Campers fascia (superficial fatty layer) - Scarps fascia (deep fibrous layer)
- External Oblique - Internal Oblique - Transversus abdominus muscle
- Fascia transversals - Peritoneum
What is the significance of the arcuate line in relation to the posterior wall?
Above the arcuate line, the posterior wall of the rectus sheath can be found
Below the arcuate line, there is no posterior wall, only the Anterior rectus sheath
What are the origins and attachments of the external oblique and what is it innervated by?
Originates from lower 8 ribs and inserts into the Xiphoid process + Linea alba + pubic symphysis
Innervated by intercostal nerve 7-11 and subcostal nerve
In which incision must the Rectus abdominis be divided?
Kocher incision
What is the innervation of the Transversus abdominis muscle?
Intercostal nerves 7-11, Subcostal nerve and Iliohypogastric nerve
Which vessel is liable to damage at the medial extension of the Grid Iron incision?
Inferior epigastric artery within the rectus sheath
Why are haematomas of the rectus abdominis usually localised?
Due to Tendinous intersections of the sheath
The internal and external rings of the inguinal canal are opening in which structures?
Internal ring: opening in the transversals fascia (inch above the midpoint of the inguinal ligament)
External ring: opening of the external oblique aponeurosis
What are the boundaries of the inguinal canal?
Anteriorly: Ext oblique / trasnversus abdominis
Posteriorly: Fascia trasversali
Roof: Arching fibres of Int oblique / transverses abdominis
Floor: Inguinal ligament
What are the attachments of the inguinal ligament?
ASIS to Pubic tubercle
Where is the mid inguinal point?
Midway between AIS and pubic symphysis (surface anatomy of femoral artery)
Where is the mid point of the inguinal ligament?
Midway between ASIS and pubic tubercle and is the location of the deep ring
What causes a paralytic hernia?
Damage to the ilioinguinal nerve (which supplies conjoint tendon that reinforces posterior wall)
Damage can occur during open appendicectomy
Which structure prevents descent of direct hernia into scrotum?
Conjoint tendon
What are the boundaries of the Hesselbach triangle?
Medial: Rectus abdominis
Lateral: Inferior epigastric vessels
Inferior: Inguinal ligament
Which part of the inguinal canal lies in the Hesselbach’s triangle?
Superficial (external) ring of the inguinal canal
What is a direct hernia and how does it present anatomically?
Caused by a defect in the posterior wall and will protrude medially to the inferior epigastric vessels through Hesselbach’s triangle
Never descends into the scrotum
What is the origin and insertion of the lacunar ligament?
Starts at the medial end of the inguinal ligament and inserts into Pecten pubis on superior ramus of pubic bone
What is the innervation of the cremasteric muscle?
Genital branch of genitofemoral nerve
What is the dermatome of the diploid region?
T7
Where is the L1 dermatome?
Inguinal fold region
What are the 12 structures found in the transpyloric plane?
- Termination of spinal cord
- Renal hilum (left)
- SMA
- 9th rib
- Portal vein
- Neck of pancreas
- Pylorus of stomach
- 2nd part of duodenum
- Sphincter of Oddi
- Duodenojejunal flexure
- Fungus of gallbladder- L1 vertebral body
In which fold is the urachus found and what may occur if the urachus remains patent?
Median umbilical fold
If urachus is patent, urine will come out of the umbilicus
What is the name of the visceral layer covering the testis?
Tunica vaginalis
Is the ilioinguinal nerve part of the spermatic cord?
No
content of the inguinal canal, not spermatic cord
What are the contents of the spermatic cord?
(3 arts, 3 nerves, 3 structures)
Arteries:
- Testicular artery
- Cremasteric artery
- Artery of the vas
Nerves:
- Genital branch of the genitofemoral nerve
- Sympathetic ns around testicular artery
- Sympathetic ns around artery to vas
Structures:
- Pampiniform plexus
- Vas deferans
- Obliterated processus vaginalis
What are the coverings of the spermatic cord (from deep to superficial)?
Internal spermatic fascia (continuation of transversals fascia) –> Cremasteric fascia –> External spermatic fascia
How many medial and lateral umbilical folds are there?
2 medial and 2 lateral
What are the borders of Hesselbach’s triangle and what is the significance of this in relation to differentiation of hernias?
Medial: Rectus abdominis
Lateral: Inferior epigastric vessels
Inferior: Inguinal ligament
Hernias within Hesselbach’s triangle are direct. Outside of this triangle, they are in indirect
