5. Abdomen I Flashcards
What are the 3 superior boundaries of the anterior abdominal wall?
- xiphisternal joint
- xiphoid process
- costal margin
What are the 4 inferior boundaries of the anterior abdominal wall?
- iliac crest
- pubic symphysis
- inguinal ligament
- ASIS
Where does the inguinal ligament attach?
- to the ASIS and the pubic tubercle
What kind of a joint is the pubic symphysis?
- secondary cartilaginous
What are 6 soft tissue landmarks of the anterior abdominal wall?
- umbilicus L4
- external oblique
- linea semilunaris
- rectus abdominis
- linea alba
- tendinous intersections
What 2 planes divide the abdomen into 4 quadrants?
- transumbilical
- median
What 3 planes divide the abdomen into 9 regions?
- transpyloric/subcostal
- intertubercular
- midclavicular
What 7 structures can be found at the transpyloric plane?
- origin of superior mesenteric artery
- origin of portal vein
- hilum of left kidney
- origin of renal arteries
- duodenojejunal flexure
- termination of spinal cord
- pylorus
What are the 4 structures found in the transtubercular plane?
- tubercles of the iliac crest
- L4/L5
- origin of IVC
- confluence of common iliac veins
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Label this image
At what level is the transpyloric plane?
- L1
At what level is the subcostal plane?
- L2
At what level is the transtubercular plane?
- L4/L5
What 2 fascia does the superficial fascia become?
- Camper’s fascia (fatty)
- Scarpa’s fascia (membranous)
What is the Camper’s fascia continuous with? (4)
- superficial fascia of thigh
- superficial fascia of penis
- dartos fascia (male)
- perineum and labia majora (fem)
What is Scarpa’s fascia continuous with? (4)
- fascia lata of thigh
- superficial ligaments of penis
- colles’ fascia (male)
- perineum and labia majora (fem)
What does the superficial fascia contain?
- fat
- superficial veins and nerves of the anterior abdominal wall
Label this image
Where can urine pool in men if the urethra ruptures?
- in the superficial perineal space
- scrotum
- lower anterior abdominal wall
What is the fiber direction of the external oblique muscles?
- inferomedial
What is the anterior border of the rectus sheath?
- medial aponeurosis
Where does the inguinal ligament go from and to?
- ASIS to pubic tubercle
What is the inferior border of the external oblique?
- inguinal ligament
What is the origin of the external oblique?
- external surfaces of 5-12th ribs
What is the insertion of the external oblique (3) ?
- linea alba
- pubic tubercle
- anterior half of iliac crest
What is the nerve supply of the external oblique?
- thoracoabdominal nerves (T7-T11) and subcostal nerve (T12)
What is the function of the external oblique?
- compresses and supports abdominal viscera, flex and rotate trunk
What is the anterolateral wall of the abdomen made up of?
- 3 flat muscles : external oblique, internal oblique and transversus abdominis
What are the muscles of the anterolateral abdominal wall equivalent to?
- intercostal muscles of the thorax
What is the fiber direction of the internal oblique muscles?
- superomedial
What is the origin of the internal oblique?
- thoracolumbar fascia
- anterior 2/3 of iliac crest
- connective tissue deep to inguinal ligament
What is the insertion of the internal oblique?
- inferior border of 10th-12th ribs
- linea alba and pubis via conjoint tendon
What is the nerve supply of the interal abdominal muscles?
- thoracoabdominal (T7-T11)
- subcostal (T12)
- iliohypogastric (L1)
- ilioinguinal (L1)
What is the function of the internal oblique muscle?
- compresses and supports abdominal viscera
- flex and rotate the trunk
What is the direction of fibers in the transverse abdominis?
- transverse fiber direction
Where is the neurovascular plane?
- between the internal oblique and rectus abdominis
What is the origin of the transverse abdominis?
- internal surface of 7th-12th costal cartilages
- thoracolumbar fascia
- iliac crest and connective tissue deep to lateral 1/3 inguinal ligament
Where is the insertion of the transverse abdominis?
- linea alba
- pubic crest
- pectin pubis via conjoint tendon
What is the nerve supply to the transverse abdominis?
- thoracoabdominal (T7-T11)
- subcostal (T12)
- iliohypogastric (L1)
- ilioinguinal (L1)
What is the action of the transverse abdominis?
- compresses and supports the abdominal viscrea
- antagonistic to diaphragm
What two muscles are enclosed in the rectus sheath?
- rectus abdominis
- pyramidalis
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Label this image
Label this image
Label all the layers
What is the investing fascia?
- connective tissue in-between muscles
What is the transversalis fascia?
- very thick layer of investing fascia posterior to the transversus abdominis
What is the extraperitoneal fascia?
- contains varying amounts of fat
What kind of muscle is the rectus abdominis?
- paired strap muscle
What are the rectus abdominis separated by?
- linea alba
What does the lateral border of the rectus abdominis form?
- linea semilunaris
What is the origin of the rectus abdominis?
- pubic symphysis and pubic crest
What is the insertion of the rectus abdominis?
- xiphoid process
- 5-7th costal cartilages
What is the nerve supply of the rectus abdominis?
- thoracic abdominal nerves T7-T11
- subcostal nerve T12
What is the action of the rectus abdominis?
- compresses abdominal viscera
- flexion of trunk
- controls tilt of pelvis
What is an aponeurosis?
- tendonlike material that anchors a muscle or connects it with the part that the muscle moves
What is the origin and insertion of the pyramidalis muscle?
- origin : pubic crest
- insertion : linea alba
What is the nerve supply for the pyramidalis?
- subcostal nerve T12
What is the action of the pyramidalis muscle?
- tense linea alba
What is the rectus sheath?
- aponeurosis of : external oblique, internal oblique and transversus abdominis
What does the rectus sheath envelop?
- rectus abdominis
- pyramidalis
- superior and inferior epigastric vessels
- distal portions of thoracoabdominal nerves
- corresponding lymphatics
What is the linea alba made of?
- interlacing fibers of anterolateral muscles
Where does the linea alba go from and to?
- xiphoid process to pubic crest
What is the surgical importance of the linea alba?
- no blood supply
How is the linea alba formed?
- fusion of the anterolateral abdominal muscle aponeuroses in the midline
Where does the linea semilunaris cross the costal margin?
- 9th costal cartilage
What is the arcuate line?
- crescent shape line that represents a weakening of the anterior abdominal wall
How is the arcuate line formed?
- due to a change in the structure of the anterior and posterior lamellae of the rectus sheath
Where does the anterior laminae of the internal aponeurosis go above the arcuate line?
- anterior to rectus abdominis
Where does the posterior laminae of the internal aponeurosis go above the arcuate line?
- posterior to rectus abdominis
Below the arcuate line where do the aponeuroses go?
- anterior to rectus abdominis
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Where do hernias usually occur in relation to the arcuate line and why?
- becuase below the arcuate line the abdominal wall is weaker
Where does the superior epigastric arise from and what vessel does it anastomose with?
- continuation of the internal thoracic artery and it anastomoses with the inferior epigastric
Where does the inferior epigastric arise from and what vessel does it anastomose with?
- inferior epigastric artery arises from the external iliac artery
- anastomoses with the superior epigastric artery
Where does the inferior epigastric vein drain to?
- external iliac
What is the median umbilical ligament?
- remnant of the fetal urachus which is a remnant of the allantois
Label this image with
1) superficial epigastric
2) superficial circumflex iliac
3) inferior epigastric
4) superior epigastric
5) thoraco epigastric
6) musculophrenic
What is a rectus sheath haematoma caused by?
- rupture in inferior epigastric artery which ascends between rectus abdominis and posterior laminae of rectus sheath
What patients are more likely to develop a rectus sheath haematoma?
- more common in patients on anti coagulants
What was the embryological function of the medial umbilical ligament?
- removal of the neonate’s nitrogenous waste through the placenta
What does the medial umbilical fold overlie?
- the remnant of fetal umbilical artery
What does the lateral umbilical fold overlie?
- the inferior epigastric artery
What incision is done for a cholecystectomy?
- Kocher’s
What incision is done to access the pancreas or biliary tree?
- rooftop
What incision is done to repair abdominal aortic aneurysms?
- transverse
What incision is done for a C section, prostatectomy or cystectomy?
- Pfannenstiel
Where does the inguinal ligament run from and to?
- from ASIS to pubic tubercle
What forms the free border of the external oblique?
- inguinal ligament
What is the pectineal line?
- extension of lacunar ligament that passes along the pectin pubis
What is the conjoint tendon?
- aponeurosis of internal oblique and transverse abdominis fuse together to form a thickening (only inferiorly)
What is the conjoint tendon attached to?
- pubic crest and pectineal line
What is the lacunar ligament?
- crescent shaped extension of medial fibers of inguinal ligament
Label the 3 ligaments shown here
Identify the boundaries of Hesselbach’s (inguinal) triangle?
- Medial – lateral border of the rectus abdominis muscle.
- Lateral – inferior epigastric vessels.
- Inferior – inguinal ligament
- Superolateral border: Inferior epigastric vessels
What is the function of the inguinal canal in males?
- allows spermatic cord to pass to and from testes
What is the function of the inguinal canal in females?
- permits passage of the round ligament of the uterus
What are the 2 openings of the inguinal canal?
- deep inguinal ring : entrance to canal
- superficial inguinal ring : exit of canal
Label this image with
1) ASIS
2) external oblique
3) aponeurosis of external oblique
4) inguinal ligament
5) femoral artery and vein
6) lacunar ligament
7) pubic tubercle
How is the inguinal ligament related to the external oblique muscle?
- The aponeurosis of the external oblique muscleforms the inguinal ligament
Where do the external iliac artery and vein become?
- passes into the thigh, under the inguinal ligament to become the femoral artery and vein.
Why does the inguinal canal form?
- formed due to the embryological descent of the testes, from the posterior abdominal wall, through the layers of the inferior part of the anterior abdominal wall, to reside within the scrotum
What are the boundaries of the inguinal canal (MALT) ?
- 2 Muscles - Roof: Overarching fibres of internal oblique and transversus abdominis
- 2 Aponeuroses - Anterior Wall: Aponeuroses of external and internal oblique muscles
- 2 Ligaments - Floor: Inguinal ligament and lacunar ligament
- 2 Ts - Posterior Wall: Conjoint tendon and transversalis fascia
What is the superficial inguinal ring?
- triangular shaped opening in the aponeurosis of the external oblique muscle
Where is the superficial ring palpable in males?
- 2 – 3 cm superolateral to the pubic tubercle by invaginating the skin of the upper scrotum with the index finger during clinical examination.
What is the deep inguinal ring?
- a slit-like opening in the transversalis fascia
Where is the deep inguinal ring?
- 2cm above the midpoint of the inguinal ligament
Label this image with
1) internal oblique
2) external oblique aponeurosis
3) superficial inguinal ring
4) ilioinguinal nerve
5) deep inguinal ring
6) spermatic cord
7) anterior layer rectus sheath
8) scrotum
What is the relationship between the inferior epigastric vessels and the deep inguinal ring?
- vessels are medial to the ring
What structures does the inguinal canal contain in males and females?
- spermatic cord (males)
- round ligament of uterus (females)
- inguinal canal contains the ilioinguinal nerves
Where do gonads develop and how do they move down?
- gonads develop in layers between the parietal peritoneum and the transversalis fascia
- they get pulled down by the gubernaculum
What is the gubernaculum and what are the cranial and caudal ends attached to?
- cord like structure that is made of mesenchymal tissue
- cranial end is attached to the gonads and the caudal end is attached to the labioscrotal folds
What is the midpoint attachment of the gubernaculum?
- uterus
What is the spermatic cord covered by?
- 1) Internal spermatic fascia from the transversalis fascia.
- 2) Cremasteric muscle and fascia from the internal oblique muscle and fascia.
- 3) External spermatic fascia from external oblique muscle.
What does the spermatic cord have 3 of? (CANT)
- 3 coverings
- 3 arteries
- 3 nerves
- 3 tubes
What are the 3 arteries in the spermatic cord?
- testicular arteries
- artery to vas deferens
- cremasteric artery
What are the 3 nerves of the spermatic cord?
- sympathetic
- parasympathetic
- genital branch of genitofemoral nerve
What are the 3 tubes in the spermatic cord?
- 1) vas deferens
- 2) pampiniform plexus
- 3) lymphatics
When does the process vaginalis develop?
- 2nd to 3rd month of gestation
What is the process vaginalis?
- tubular extension of peritoneal cavity
What happens to the process vaginalis?
- herniates through the abdominal wall along the path formed by the gubernaculum
- extensions of layers of abdominal wall accompany it and form walls of the inguinal canals, spermatic cord and testes
What happens to the process vaginalis after it has herniated in males?
- scrotal part of the process vaginalis remains patent as the tunica vaginalis
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As the gonad is pulled down by the gubernaculum what does it pick up?
- layers of anterior abdominal wall
Where do the testicular arteries arise?
- from the front of the aorta
Where does the cremasteric artery come from?
- from the inferior epigastric artery
Where does the artery to the vas deferens originate?
- internal iliac
What does the round ligament attach to?
- It attaches to the uterus
- passes through the inguinal canal and continues to spread out within the labia majora.
What is an inguinal hernia?
- protrusion of parietal peritoneum and viscera, such as the small intestine, through a normal or pathological opening in the body wall
Where does a direct inguinal hernia go?
- directly through abdominal wall
- medial to inferior epigastric artery
- exits via the superficial inguinal ring lateral to the spermatic cord
How does an indirect inguinal hernia occur?
- lateral to inferior epigastric artery
- passing through length of canal
- exits via superficial inguinal ring and can pass into the scrotum/labium majus
What is the female equivalent of the scrotum?
- labia majora
Are both types of hernias equally common in both sexes?
- Indirect inguinal hernias are congenital hernias and are much more common in males than females
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How do femoral hernias differ from indirect hernias?
- a femoral hernia will pass below and lateral to the pubic tubercle, whereas an inguinal hernia will be seen above and medial to it.
Why is a femoral hernia more likely to strangulate?
- due to the narrow femoral canal and femoral ring
Which hernias are more common in women than men and why?
- Femoral Hernias
- Due to the wider width of the pelvis
What are the 8 layers of the anterior abdominal wall?
- skin
- subcutaneous tissue (fatty and membranous)
- external oblique muscle and aponeurosis
- internal oblique muscle
- fascia of internal oblique muscle
- transversus abdominis muscle
- transversalis fascia
- peritoneum
What are the 8 layers of the spermatic cord?
- skin
- dartos fascia + muscle
- external spermatic fascia
- cremasteric muscle
- cremasteric fascia
- X
- internal spermatic fascia
- vestige of process vaginalis
What are the 8 layers of the scrotum and testis?
- skin
- dartos fascia + muscle
- external spermatic fascia
- cremaster muscle
- cremasteric fascia
- X
- internal spermatic fascia
- tunica vaginalis
What is hydrocele?
- collection of fluid in the tunica vaginalis
- increase fluid secretion from visceral layer of tunica vaginalis
What is testicular torsion?
- Twisting of the spermatic cord above its attachment to the testis
- Cuts off blood supply
