Inguinal region and hernias Flashcards
Where does the inguinal region (groin) extend between?
-The ASIS (anterior superior iliac spine) and pubic tubercle
What is the inguinal region?
-Thickened, under-turned and inferior margin of the aponeurosis of the external oblique
-Allows muscles and neurovascular structures supplying the lower limb to pass through
Inguinal ligament and surrounding structures
Inguinal ligament
-inferiormost part of the external oblique aponeurosis
-although most fibres insert into pubic tubercle, some follow other course
-Some attach to superior pubic ramus forming lacunar ligament
-Some of these fibres continue to along the pecten pubis as the pectineal ligament
-Some fibres bypass the pubic tubercle, cross the linea alba, and blend with the contralateral external oblique aponeurosis to form the reflected inguinal ligament
What does the inguinal canal contain?
-Ilioinguinal nerve
-Spermatic cord (males)
-Round ligament of uterus (females)
(ILIOINGUINAL NERVE IS NOT IN THE SPERMATIC CORD)
Structures in the inguinal canal
Inguinal canal resembles a flattened tube with an opening at each end:
Deep inguinal ring
-Superior to the midpoint of the inguinal ligament and lateral to the inferior epigastric vessels
-An opening in the transversalis fascia
Superficial inguinal ring
-Superior and lateral to pubic crest
-Has a medial and lateral margin (medial and lateral crura) that attach to pubic crest and pubic tubercle respectively
Intercrural fibres prevent crura from spreading apart
Boundaries of the inguinal canal
How do anatomical layers of abdominal wall match up to spermatic cord?
-Transversalis fascia -> internal spermatic fascia
-Fascia of internal oblique muscle -> cremasteric fascia
-Internal oblique muscle -> cremaster muscle
-External oblique aponeurosis and its fascia -> external spermatic fascia
Features of cremaster muscle
-Striated muscle innervated by genital branch of genitofemoral nerve (L1-2)
-When cold, cremaster contracts and draws the testis superiorly
-When warm, cremaster muscle relaxes and testis descend in scrotum
Does the round ligament of the uterus have corresponding coverings like the spermatic cord?
No, they are indistinct along the round ligament
What is the processus vaginalis?
-Extension of the peritoneum
-Terminal portion forms the tunica vaginalis which cushions the testis
-Rest of processus vaginalis degenerates and is found as the vestige of processus vaginalis within the spermatic cord
How is a hydrocele formed?
-Patent processus vaginalis allows fluid to move into tunica vaginalis from peritoneal cavity
-This results in enlargement of a serous sac called a hydrocele
Contents of spermatic cord
What is a hernia?
-An abdominal hernia is a protrusion of the peritoneum (could include viscera) through the abdominal boundaries
-They arise in areas of weakness in the abdominal wall
Where do most hernias occur?
-Inguinal
-Umbilical regions
-Epigastric
Where do the majority of inguinal hernias occur and in who?
-Majority of abdominal hernias occur in inguinal region (75%)
-Inguinal hernias more common in males due to wider inguinal canal with passage of the spermatic cord
Symptoms of hernias
-Lump in groin which disappears with minimal or when patient lies down
-Cough impulse - impulse felt against examiner’s fingers when patient is asked to cough
Direct vs Indirect inguinal hernias
Indirect:
-hernia goes through inguinal canal lateral to inferior epigastric vessels
-to enter deep inguinal ring
Direct:
-hernia passes medial to inferior epigastric vessels
-pushing through peritoneum and transversalis fascia in inguinal triangle
-to enter inguinal canal
What is the inguinal triangle?
-Also called medial inguinal fossa
-Potential site for direct inguinal hernias
Borders:
Medial: lateral margin of the rectus abdominis
Lateral: inferior epigastric vessels
Inferior: inguinal ligament
What is the femoral canal?
-Femoral artery and vein are contained within the femoral sheath
-Space within the femoral sheath is called the femoral canal
How can hernia occur in femoral canal?
-Proximal end of femoral canal is the femoral ring and presents a weak spot where femoral hernia can occur
-Inferior to the inguinal ligament, there is an opening of the femoral sheath (saphenous opening), where superficial veins and lymphatics drain into deep vessels
-Femoral hernia protrudes through femoral canal and saphenous opening
Who is femoral hernia more common in and why?
-Females
-Wider hips and and wider femoral canal
Inguinal vs femoral hernia
-Inguinal hernia is above and medial to pubic tubercle
-Femoral hernia is below and lateral to pubic tubercle
