6. Abdominal wall, inguinal region and hernias 1.pptx Flashcards
What structures are beneath the 4 quadrants of the abdomen?
RUQ: Liver and gall bladder
RLQ: Ileum, caecum, appendix
LUQ: Jejunum
LLQ: Sigmoid colon
Which 4 lines are used to determine the 9 regions of the abdomen?
Midclavicular Lines (2)
Subcostal Plane just below the costal margin at L3
Inter (trans) tubercular / Supracristal plane between the iliac crests at L4/5
What is the umbilicus?
A scar representing the site of attachment of the umbilical cord in the foetus
How is the superficial fascia of the abdominal wall divided?
- Camper’s fascia: a superficial, fatty layer
2. Scarpa’s fascia: A deeper membraneous layer
What is the composition of the internal fascia in the abdominal wall?
- There are very thin, negligible layers of fascia between the muscles
- Deep to the muscles (but outside the peritoneum), there is a layer of endo-abdominal or transversals fascia
- Variable exztraperitoneal fat which is immediately external to the peritoneum
What happens to the abdominal superficial fascia on descending to the scrotum?
Camper’s is replaced by dartos
Scarpa’s extends into the penis and scrotum, to become, Colle’s perineal fascia. This fuses with the fascia lata of the thigh below the inguinal ligament
What is distinctive about bruising that is trapped under scrap’s fascia?
On front only
“Blue swimming shorts”
In the abdomen, what fascia layers are found deep to the muscle layer?
Transversalis
Extraperitoneal fascia
Thoracolumbar fascia passes from the ____ ____ to the 12th rib and is in 3 layers (___, ___, ____) that surround the back muscles and fuse together and give origin to transversus ______ and internal oblique, but not external oblique
Thoracolumbar fascia passes from the iliac crest to the 12th rib and is in 3 layers (anterior, middle and posterior) that surround the back muscles and fuse together and give origin to transversus abdominis and internal oblique, but not external oblique
What is the transversals fascia?
A thin layer of fascia that lines the transversus abdominis muscle and is continuous with a similar layer lining the diaphragm and the iliac muscle.
What is the extraperitoneal fascia?
A thin layer of fascia that contains a variable amount of fat and lies between the transversal is fascia and the parietal peritoneum.
What are the anterior abdominal wall muscles?
3 broad, thin sheets: (sup) 1. External oblique 2. Internal oblique 3. Transversum abdominis
A vertical muscle Rectus Abdominis (and Pyramidalis)
What are the functions of the anterior abdominal wall muscles?
- Support abdominal contents and raise intra-abdominal pressure, withstanding pressure from descent of the diaphragm
- Support vertebral column, flexing, laterally flexing and rotating the trunk against resistance
- Respiration
External oblique:
Attachments?
Fibre direction?
Nerve supply?
Attachments:
From- Lower 8 ribs, lateral lip of iliac crest, aponeurosis to linea alba via rectus sheath
To- forms the inguinal ligament
Fibre direction: Downwards and medially
Nerve supply: T7-12
What is the inguinal ligament? What is it’s attachments?
Continues as?
Inrolled, inferior edge of external oblique.
From ASIS to pubic tubercle
Continues as lacunar and pectineal ligaments
What is the superficial ring?
Triangular opening in external oblique aponeurosis with its base at the pubic crest
Internal oblique:
Attachments?
Fibre direction?
Nerve supply?
Attachments:
From- Thoracolumbar fascia, iliac crest, lateral 2/3rd of inguinal ligaments, lower 3/4 ribs and CC’s, aponeurosis
To- Linea alba via rectus sheath, pubic crest behind the superficial inguinal ring via conjunct tendon
Fibres pass upwards and medially to ribs,
but downwards to conjoint tendon
Nerve supply: T7 to 12 plus L1 via iliohypogastric nerve to the fibres that form the conjoint tendon
What is the consequence of injury to the iliohypogastric nerve?
Weakness on the conjoint tendon and predisposed to inguinal hernias
Transversus abdominis:
Attachments?
Fibre direction
Nerve supply?
Attachments:
From-Thoracolumbar fascia, iliac crest, lateral 1/3rd or half of inguinal ligament, lower 6 ribs + CCs, aponeurosis
To- Linea alba via rectus sheath, pubic crest behind the superficial inguinal ring via conjoint tendon
Fibres pass transversely to ribs,
linea alba and conjoint tendon
Nerve supply: T7 to 12, plus L1 via the iliohypogastric nerve to the fibres that form the conjoint tendon
What is the conjoint tendon formed from? Attachements?
Formed from the aponeuroses of internal oblique and transversus abdominis
It attaches to the pubic crest and pectineal line behind the superficial inguinal ring, therefore supports the ring
Rectus abdominis:
Attachments?
Fibre direction?
Nerve supply?
Attachments: CC of ribs 5-7, diploid, pubic symphysis, pubic crest and pectineal line
Fibres pass vertically with tendinous intersections
Nerve supply: T7 to 12
What is pyramidalis?
A small triangle anterior to RA.
From pubic crest to linea alba
What forms the rectus sheath?
Each rectus abdominis is enclosed anteriorly and posteriorly between the bilaminar aponeuroses of the EO, IO and TA. This forms the rectus sheath
In the midline they fuse as the linea alba
What happens to the rectus sheath at the arcuate line?
All aponeuroses pass anteriorly and the posterior sheath ends.
This allows inferior epigastric vessels to enter the sheath behind rectus abdominis
Inguinal canal:
What is it?
Created by?
Contains?
What is it?
An oblique passage through the anterior abdominal wall. Has 2 openings, deep and superficial rings. Each ring is protected by 2 of the 3 muscles
Created by the descent of the testis, pushing through the 3 layers of the muscle
Contains:
- Vas deferens and testicular vessels in male (round ligament in females)
- Ilio-inguinal nerve
- Genital branch of genitofemoral nerve
Superficial inguinal ring:
Location?
Structural features?
Location: Triangle in external oblique at base of pubic crest
Structural features: Medial and lateral crura. Supported from behind by conjoint tendon (IO + TA)
Deep inguinal ring:
What is it?
Transmits which structures?
Position?
Opening in the transversal is fascia. Overlain by internal and external oblique.
Trasmits vas deferens and gonadal vessels (in spermatic cord)
Position: Lies lateral to the inferior epigastric vessels, half way between the ASIS and the pubic tubercle
What muscles make up the walls, roof and floor of the inguinal canal?
Anterior wall: EO with IO laterally
Posterior wall: Conjoint tendon, transversals fascia laterally
Roof: Arching fibres of IO and transversus abdominis
Floor: Inrolled lower edge of inguinal ligament, strengthened medially by lacunar ligament
What is a hernia?
A protrusion of a viscus through the wall of its containing cavity
What is the normal location of an inguinal and femoral hernia?
Inguinal hernia: Above and medial to the pubic tubercle
Femoral hernia: Passes through the femoral canal and appears below and lateral to the pubic tubercle
What is the difference between a direct and indirect inguinal hernia?
Direct: Through the posterior wall of the inguinal canal medial to the inferior epigastric vessels. Ends up in the scrotum, parallel to spermatic cord and with it’s own covered of peritonium, transversals fascia, conjoint tendon and external oblique as external spermatic fascia
Indirect: Through the deep inguinal ring lateral to the inferior epigastric vessels. Bowel in the spermatic cord, covered by parietal peritoneum and passing through deep inguinal ring of transversalis fascia.
What forms internal spermatic fascia at the deep ring?
Transversalis fascia
How will a hernia that causes obstruction present?
Colicky abdominal pain
Distension
Vomiting
Hernia will be tense, tender and irreducible
How will a hernia that causes strangulation present?
Red and tender
