Session 3: Case Studies Flashcards
Why might you present with periumbilical pain due to appendicitis?
The appendix is part of the midgut. The sympathetic nervous system feeds back in reverse when sensing pain. This means that pain will be sensed in the T10-T11 nerve roots and pain will shoot out in that region as the lesser splanchnic nerve supplies the midgut. Why it is around the umbilicus is because the innervation is bilateral.
Referring to the differences between the visceral and parietal peritoneum, explain why the focus of pain has moved to the right iliac fossa.
The appendix come in contact with the right iliac fossa as it swells due to the inflammation. By the right iliac fossa the appendix will come in contact with parietal peritoneum which has somatic innervation.
Somatic innervation is much more localised and will be felt where the inflammation occurs.
Where in the abdomen would someone with stomach ulcers feel pain?
The stomach is found in the foregut. A stomach ulcer would produce visceral pain.
The foregut is supplied by the greater splanchnic nerve so tracking back to the nerve roots pain would be felt in the T5-T9 region aka the epigastric area.
Describe the path an indirect inguinal hernia takes as it leaves the confines of its containing cavity.
Deep inguinal ring -> Inguinal canal -> Superficial inguinal ring
Indirect inguinal hernias are a result of developmental defect. Briefly describe this defect.
As the testes descend from the abdominal cavity to the pelvic cavity it will take along part of the peritoneal cavity known as the processus vaginalis.
As the testes reach their final destination the processus vaginalis is meant to obliterate to only have the remnant left called the tunica vaginalis.
Sometimes the processus vaginalis only obliterate partially or not at all. This leads to a link between the abdominal cavity and the pelvic cavity. The link is processus vaginalis and the inguinal canal.
From an anatomical point of view, how does and indirect inguinal hernia differ from a direct one?
We label a hernia from where it left its containing cavity. Even if an indirect hernia ends up in the scrotum we don’t called it a scrotal hernia, we call it indirect.
An indirect hernia herniates via the deep inguinal ring lateral to the inferior epigastric artery.
A direct hernia herniates medial to the inferior epigastric artery in the hesselbach’s triangle.
Why can the clinical presentation of an indirect and a direct inguinal hernia be so similar?
Because they can both protrude through the superficial inguinal ring.
How would you by a simple test be able to discern whether the hernia is direct or indirect?
Push back the hernia to its original place.
Press now on the deep inguinal ring and ask the patient to cough.
An indirect hernia would not come back out, a direct hernia would.
Describe the typical patient who might present with a direct inguinal hernia.
Elderly men which are obese, chronically coughing and previous surgery.
If a hernia cannot be pushed back, what is it called?
An incarcerated hernia.
How does an incarcerated hernia differ from a strangulated hernia.
A strangulated hernia has its blood supply restricted and can become ischaemic.
Briefly describe the path of a femoral hernia as it leaves the abdomen.
Its goes through the femoral triangle via the femoral ring through the femoral canal and out of the saphenous opening.
This is inferior to the inguinal ligament.
What are the fundamental differences between gastroschisis and omphalocoele?
Omphalocoeles have peritoneum and is a failure of the bowel to retract into the abdominal cavity. The signals that start the retraction of the bowel are linked to signals which do not work in some genetic defects like trisomy 13, 17 and 21. This means that it is more fatal due to genetic abnormalities.
Gastroschisis is the failure of the abdominal wall to close during the folding of the embryo. This leaves the gut tube and derivatives outside of the body cavity and not covered in any peritoneum at all. Children with gastroschisis has a better chance of survival.
