ANAT GIT - Week 3 (incl. ANAT Workbook) Flashcards
What is the rectus sheath? What does it contain?
Fascial coverings of the ext oblique, int oblique, transversalis abdominis muscles. Contains rectus abdominis & pyramidal mms.
Lateral abdo wall includes what muscles
Ext oblique, int oblique, transversus abdominis
Anterior abdo wall includes what muscles
Rectus abdominis, pyramidalis
Fibre arrangement of the external intercostals
‘Hands in pockets’
Fibre arrangement of the internal intercostals
‘Hands in inside pockets’
Characteristic of abdo wall superior & inferior to the arcuate line
Stronger. Inferior - clinically, herniation is more liely here.
Location of linea alba
Midline
Location of linea semilunaris
Mid-clavicular line.
Location of the arcuate line
Rectus sheath @ umbilicus.
What layer forms the median, medial & lateral umbilical folds?
Pareital pleura/peritoneum.
What does the lateral umbilical fold contain?
Inferior epigastric artery.
What does the median umbilical fold contain?
Urachal remnant
What does the medial umbilical fold contain?
Obliterated foetal umbilical arteries.
Classification of hernia - medial to inferior epigastric artery/lateral umbilical fold
Direct.
Classification of hernia - lateral to inferior epigastric artery/lateral umbilical fold
Indirect.
What is the urachus?
Remnant of the channel btw bladder & umbilicus where urine initially drains in the foetus in the 1st trimester (usually obliterated by 12 wks gestation).
Which structures form the inguinal triangle of Hesselbach?
Rectus abdominis, inguinal ligament, inferior epigastric artery.
Clinical significance of triangle of Hesselbach
Potential area of weakness in abdo wall => potential site of herniation.
What does the inferior epigastric artery originate from?
External iliac artery.
Through which structure does an indirect inguinal hernia traverse?
Inguinal canal.
Through which structure does a direct inguinal hernia traverse?
Triangle of Hesselbach.
What does the ‘bag of worms’ sign indicate when shining a light on a swollen scrotum?
Variocele.
What does a lack of conjoint tendon increase the risk of?
Direct hernia.
(Conjoint tendon located medial part of post inguinal canal wall).
Pancreas appearance in traverse CT section
U shaped, open post.
R gonadic vein drains into
IVC
L gonadic vein drains into
L kidney
Retroperitoneal vs intraperitoneal components of the duodenum.
1st part = retro. 2nd part = intra. (after duodenjejunum flexure/@ ligament Trietz).
3 structures contributing to testis temperature control
Tunica dartos - smooth muscle @ subdermal layer (reduce SA via contraction - trap heat & increase SA via relaxation - release heat).
Cremaster muscle - smooth muscle (reduce heart loss by contracting to draw testis closer to abdo)
Testicular vascular cone - highly coiled to function as counter-current heart exchange (enable transfer of heart from artery - vein).
Strangulated hernia
Hernia contents & surrounding tissue becomes ischaemic.
Why is a femoral hernia more likely to strangulate?
Narrow ‘neck’ bulge passes through.
Why is a femoral hernia more likely in females?
Due to increased pelvic structures & pregnancy associated increased intra-abdominal pressure.
Cryptochidism
Undescended testis.
Cryptochidism places pts at increased risk of what condition.
Tumour development.
Which testis more frequently does not descend? Why?
R as R testis descends later.
Complications of cryptochidism
Infertility due to high body temp.
Ectopic testis
Descent of testes deviates from normal developmental pathway (exits via external inguinal canal).
Retractile testis
Cremastor muscle reflex causes testes to move up/down within scrotum.
Why might the L testicle hang lower?
High temp than R -> looser.
Variocele
Enlargement of scrotal veins due to torsion of pampiniform plexus.
Variocele more commonly affects which testicle? Why?
L. L testicle hands lower. Superior mesenteric artery sits over L renal vein -> compression & collapse of vein. L spermatic vein comes off L renal vein @ almost 90o whereas R spermatic vein comes off IVC at a smaller angle.
Torsion of testis
Testicle rotates -> twists spermatic cord -> cuts off scrotal blood supply.
Lymph drainage of testis vs scrotum
Testis - follow spermatic rod -> lymph nodes near kidneys
Scrotum - follows inguinal canal -> inguinal lymph nodes.
First palpable lymph node for stomach & testis is what
L supraclavicular node/Virchow’s node via thoracic duct (as Virchow’s node is end of thoracic duct).
Name of sign if Virchow’s node is involved
Trosier.
Potential developmental cause of testicular torsion.
Bell-clapper deformity
(Testis lack normal attachment to tunica vaginalis).
Which part of the duodenum is most mobile?
Duodenal bulb/1st part is the most mobile of the duodenal segments, because it is almost completely invested in peritoneum (the exception being its posterior surface near the gallbladder neck and inferior vena cava).
What arteries supply the rectus abdominis sheath?
Sup. & inf. epigastric a.
What is an omphalocele? What does it look like?
Omphalocele (pronounced uhm-fa-lo-seal) is a birth defect of the abdominal (belly) wall. The infant’s intestines, liver, or other organs stick outside of the belly through the belly button. The organs are covered in a thin, nearly transparent sac that hardly ever is open or broken.
What is Meckel’s diverticulum?
Meckel’s diverticulum is a small outpouching extending from the wall of the intestine and located in the lower portion of the small intestine. The pouch is a remnant of tissue from the embryonic development of the digestive system. Pts can present with various clinical signs, including peritonitis or hypovolemic shock. The three most common symptomatic presentations are gastrointestinal (GI) bleeding, intestinal obstruction, and acute inflammation of the diverticulum.
What is gastroschisis?
Gastroschisis is a birth defect where a hole in the abdominal (belly) wall beside the belly button allows the baby’s intestines to extend outside of the baby’s body. The hole can be small or large and sometimes other organs, such as the stomach and liver, can be found outside of the baby’s body as well.
Gastroschisis vs omphacele.
Omphacele covered by thin membrane.
If when applying pressure to deep inguinal ring, pt coughs & hernia appears - what hernia is it?
Direct. Hernia appears via triangle of Hesselback.
If when applying pressure to deep inguinal ring, pt coughs & hernia doesn’t appear - what hernia is it?
Indirect. Hernia’s path occluded via finger in inguinal canal.
