Hernias Flashcards
(24 cards)
Define a hernia
Protrusion of part of the abdominal contents beyond the normal confines of the abdominal wall, consisting of sac, contents and covering
What is the inguinal canal?
An oblique passage through the lower abdominal wall, extending inferiorly and medially. Made up anterolateral abdominal muscles.
Describe the role of the inguinal canal in male genitalia development
Inguinal canal is pathway for testes to leave abdominal cavity and enter scrotum.
Canal is flanked by abdominal muscles and peritoneum, which out-pockets to form processus vaginalis, which usually degenerates, but if it persists can result in indirect inguinal hernia
What are the usual contents of a hernia?
Loops of bowel
Omentum
How does the inguinal canal differ between men and women?
Males- Structures pass from abdomen to testis
Females - Round ligament goes from uterus to labium majus
What is the gubernaculum?
Condensed band of mesenchyme that links inferior gonads to labioscrotal swelling
What are consequences of a partial/not obliterated processus vaginalis?
Partial - inguinal hernia
No obliteration - Scrotal hernia
What are the boundaries of the inguinal canal?
Anterior wall- Aponeurosis of external oblique and reinforced by internal oblique laterally
Posterior wall - transversalis fascia and conjoint tendon, medially
Roof- Transversalis fascia, internal oblique, transversus abdominus
Floor - Aponeurosis of external oblique (inguinal ligament) and thickened medially by lacunar ligament
What is the mid-inguinal point?
Halfway between pubic symphysis and anterior superior iliac spine
Femoral artery crosses into lower limb here
What is the midpoint of the inguinal ligament?
Midpoint of the inguinal ligament as it runs from the pubic tubercle to anterior superior iliac spine
Opening to inguinal canal is just above it
What defence mechanisms does the body have against hernias?
Walls of inguinal canal collapsed around their contents, preventing other structures from entering the canal
When intra-abdominal pressure increases, muscles of anterior and posterior wall contract and clamp down on the canal
Where are the deep and superficial rings found?
Deep - above midpoint of inguinal ligament
Superficial - superior to pubic tubercles
What is contained in the inguinal canal?
Men - Spermatic cord, to supply and drain testes
Women - Round ligament of uterus
What is an indirect inguinal hernia?
Peritoneal sac enters inguinal canal via deep ring, acquiring the same coverings as the contents of the canal
Degree of herniation depends on the amount of processus vaginalis present, so has a congenital origin IC
Lateral to inferior epigastric vessels
What is a direct inguinal hernia?
Peritoneal sac enters inguinal canal through posterior wall of inguinal canal due to acquired weakening of abdominal muscles in Hesselbach’s triangle DA
Medial to inferior epigastric vessels
What are the coverings of direct hernias when they exit the abdominal cavity?
Peritoneum
Transversalis fascia
What are the coverings of indirect hernias when they exit the abdominal cavity?
Peritoneum of persistant processus vaginalis
External spermatic fascia
Cremaster muscle and fascia
Internal spermatic fascia
Why are femoral hernias more common in women?
Wider angle of pelvis, so entrance to femoral canal via the femoral ring is wider, more likely something will go into it
What is an incarcerated hernia?
A hernia that gets stuck, is irreducible
What is a strangulated hernia?
Where blood supply is disrupted, leading to tissue necrosis
Why do femoral and inguinal hernias strangulate?
Have narrow necks
What is an umbilical hernia?
Congenital:
Omphalocele - a midgut hernia that doesn’t return, contents herniate into umbilical cord
Has a peritoneal covering
Acquired:
Contents herniate through weakness in scar of umbilicus
Adult:
Contents hernaite through linea alba in region of umbilicus
What is an epigastric hernia?
Contents herniate through linea alba, between xiphoid process and umbilicus
Chronic straining forces more fat out, eventually pulling peritoneum through
What are the symptoms of a hernia?
Loops of bowel trapped so:
Pain
Vomiting
Sepsis
