Groin (Inguinal) Region Flashcards
What is the inguinal ligament?
- formed by the lower edge of the external oblique aponeurosis
- it extends from the anterior superior iliac spine to the pubic tubercle
What is the lacunar ligament?
most medial fibers of the inguinal ligament which are inserted into the superior pubic ramus
What is the pectineal ligament?
a lateral extension of the lacunar ligament along the pecten pubis (pectineal line)
What is the inguinal canal?
- an oblique passage 3 to 5 cm in length through the anterior abdominal wall
- begins at the deep inguinal ring and ends at the superficial inguinal ring
- within the anterior abdominal wall, the deep inguinal ring lies lateral and internal, the superficial inguinal ring lies medial and external
- much larger in males than in females
What does the inguinal canal transmit?
- spermatic cord (males)
- round ligament of the uterus (females)
- ilioinguinal nerve (both sexes)
What is the conjoint tendon (inguinal falx)?
- formed by the fusion of the aponeuroses of the internal oblique and transversus abdominis muscles as they insert into the pubic crest and pecten pubis deep to the inguinal ligament
- strengthens the posterior wall of the medial half of the inguinal canal
What are the boundaries of the inguinal canal?
- Anterior wall: formed by the aponeurosis of the external oblique muscle
- Posterior wall: formed by the conjoint tendon and transversalis fascia
- Roof: formed by the arching fibers of the internal oblique and transversus abdominis muscles
- Floor: formed by the inguinal and lacunar ligaments
Describe the superficial inguinal ring.
- a triangular opening in the external oblique aponeurosis
- lies immediately lateral to the pubic tubercle
- transmits the spermatic cord in the male, round ligament of the uterus in the female, and the ilioinguinal nerve in both sexes
- these structures exit the inguinal canal and become subcutaneous at the superficial ring
What forms the superficial inguinal ring?
formed by the splitting of the external oblique aponeurosis into two crura:
- lateral crus: inserts into the pubic tubercle; some of its fibers reflect to the superior pubic ramus as the lacunar ligament
- medial crus: inserts into the pubic crest
- intercrural fibers: strengthen the apex of the superficial inguinal ring
Describe the deep inguinal ring.
- an opening within the transversalis fascia
- located above the inguinal ligament midway between the anterior superior iliac spine and the pubic symphysis
- lies just lateral to the inferior epigastric vessels
What are the boundaries of the inguinal triangle?
- medially: lateral edge of the rectus abdominis muscle
- laterally: inferior epigastric vessels
- inferiorly: inguinal ligament
What is the clinical significance of the inguinal triangle?
- it is an area of potential weakness in the anterior abdominal wall
- direct inguinal hernias occur here
Describe the development of the inguinal canal.
- The inguinal canal is present before birth, but is shorter and much less oblique than in the adult.
- At this time, the superficial inguinal ring lies almost directly anterior to the deep inguinal ring.
- During childhood development, the inguinal canal lengthens and assumes its characteristically oblique position.
What makes the inguinal canal susceptible to hernia?
- it is an area of weakness within the anterior abdominal wall
- contraction of the muscles of the anterior abdominal wall during coughing and straining elevates intra-abdominal pressure, potentially forcing abdominal contents into the canal
What anatomical adaptations function to strengthen the inguinal canal?
- The inguinal canal is oblique in adults. This allows the canal to be compressed by the muscles of the anterior abdominal wall when the contract (external oblique is most important muscle). Paradoxically, the same muscles which increase intra-abdominal pressure also narrow the inguinal canal (half-sphincter mechanism).
- Conjoint tendon: reinforces the posterior wall of the inguinal canal; can only prevent direct inguinal hernia
