Hernias Flashcards
Explain the distributions of visceral pain in the abdomen. (4)
Visceral pain is pain as a result of irritation to the visceral peritoneum, but this doesn’t have any specific pain receptors, so the fibres follow the sympathetic outflow. This means that the brain cannot tell whether the pain is from the sympathetic outflow (the splanchnic nerves) or the visceral sensors, so it refers the pain to the dermatones of the spinal nerves that make up that splanchnic nerve.
Describe the gut divisions and their distributions of visceral pain. (6)
Foregut - epigastric - greater - T5-T9
Midgut - periumbilical - lesser - T10-T12
Hindgut - suprapubic - least - L1-L2.
Define a hernia. (2)
A protrusion of part of the abdominal contents beyond the confines of the abdominal cavity.
Describe the contents of a hernia. (6)
The contents - bits of bowel
The sac - pouch of peritoneum
The covering of the sac - the abdominal wall.
Describe the two main causes of hernias. (4)
Weaknesses in the cavity - congenital, post surgery
Increased intra-abdominal pressure - obesity, lifting, chronic cough/constipation.
Describe the normal descent of the testes. (3)
Descend through the process vaginalis guided by the gubernaculum. Takes a pouch of peritoneum with them to form tunica vaginalis.
Describe what can happen is the process vaginalis is patent. (2)
Scrotal hernia
Inguinal hernia if partially closed.
Describe the layers of the walls of the inguinal canal. (6)
Anterior: skin - superficial and deep fascia - external oblique (curls underneath)
Posterior: internal oblique, transverse abdominus, transversalis fascia.
Describe the boundaries of the inguinal canal. (6)
Laterally from ASIS
Medially from pubic tubercle
Floor: inguinal ligament
Roof: transverse abdominus and internal oblique.
Deep (posterior): transversalis fascia
Superficial (anterior): aponeurosis of external oblique.
Describe inguinal hernias. (4)
75% of all hernias
M>F
Inferior epigastric vessels act as an important landmark - indirect emerge first lateral, direct emerge first medial.
Describe the borders of Hesselbach’s triangle. (3)
Medial - rectus abdominus, inferior - inguinal ligamant, superior - inferior epigastric vessels.
Describe the path of an indirect inguinal hernia. (5)
Through the deep ring, down the inguinal canal, out through superficial ring.
Can go down process vaginalis if patent.
Called lateral even though superficial ring is medial to the vessels because it FIRST emerges lateral.
Describe the path of a direct inguinal hernia. (4)
Bulges through Hesselbach’s triangle, through the posterior wall of the canal, out through the superficial ring of the canal with the posterior wall intact - doesn’t enter canal. Called medial because emerges first medial to the vessel from the superficial ring.
Describe a femoral hernia. (3)
More common in women - larger space.
Bit of bowel passes through the femoral canal (empty space in NAVEL) into the femoral triangle and out through the saphenous opening.
Describe omphalocele. (3)
Failure of midgut to return to the abdomen via the umbilicus during development. Viscera is covered in peritoneum (less serious) but often has genetic problems too (more serious) so mortality is high.
