2. Inguinal Canal Flashcards
What two nerves serve the posterior surface of the scrotum?
Posterior scrotal nerves - which come from the perineal branch of the pudendal nerve
Perineal branches of the posterior cutaneous nerve of the thigh
Which opening will gut contents pass through in a direct hernia?
The superficial inguinal ring (not the deep inguinal ring).
What are the boundaries of the inguinal triangle?
Inferior epigastric vessels
Rectus abdominis
Inguinal ligament
What two nerves serve the anterior portion of the scrotum?
Anterior scrotal nerves – which come from the illioinguinal nerve
Genital branch of the genitofemoral nerve
What innervates the dartos smooth muscle?
Sympathetic branch of the autonomic nervous system
To which lymph nodes does the lymph of the testis drain?
The lumbar nodes – a.k.a. caval/aortic
Where does the conjoint tendon insert?
The conjoint tendon inserts on the pectineal line.
What gives rise to the lacunar ligament?
Where does the lacunar ligament attach?
The lacunar ligament arises from fibers of the inguinal ligament.
The lacunar ligament attaches to the pubic tubercle.
What are the two sources of blood supply to the scrotum?
Anterior: anterior scrotal branches coming from the deep external pudendal artery
Posterior: posterior scrotal branches coming from the perineal artery (a branch of the pudendal)
What embryonic layer forms the testes and ovaries?
Intermediate mesoderm
To which lymph nodes does the lymph of the scrotum drain?
The superficial inguinal nodes
What layers of the testicle are given rise to by the internal oblique?
The cremasteric fascia and cremaster muscle
What abdominal layer gives rise to the internal spermatic fascia?
The transversalis fascia
What layers of the abdominal wall will cover gut contents in an indirect hernia?
Same as cover the spermatic cord (transversalis fascia, internal oblique aponeurosis, external oblique aponeurosis, dartos fascia)
From what other structures does the cremaster muscle originate?
Fibers from the internal oblique muscle.
What forms the roof of the deep inguinal ring, middle third of the inguinal canal, and superficial inguinal ring?
The roof of the deep inguinal ring is transversalis fascia.
The roof of the middle third of the inguinal canal are the internal oblique and transverse abdominal muscles/aponeuroses.
The roof of the superficial inguinal ring is the medial crus of the aponeurosis of the external oblique
What appears to be the purpose of the pampiniform plexus?
Thermal regulation
Where do we see direct inguinal hernias?
Where do we see indirect inguinal hernias?
Direct inguinal hernias are found in the inguinal triangle (Hesselbach’s triangle) – medial to the inferior epigastric arteries.
Indirect inguinal hernias are found lateral to the inguinal triangle – lateral to the inferior epigastric arteries.
Why do 40% of femoral hernias present with strangulation?
Because of the strength of the lacunar ligament just medial to the femoral ring.
What is the conjoint tendon?
The combined aponeuroses of the internal oblique and transversus abdominis muscles.
What gives rise to the pectineal ligament?
Where is the pectineal ligament attach?
The pectineal ligament is given rise to by fibers of the lacunar ligament, which themselves come from the inguinal ligament.
The pectineal ligament attaches to the pectineal line.
What gives rise to the intercrural fibers of the inguinal ligament?
The aponeurosis of the external oblique on the contralateral side reaching over to reinforce the parallel fibers.
What layers of the abdominal wall will cover the gut contents in a direct hernia?
Transversalis fascia, peritoneum, and skin.
What innervates the cremaster muscle?
The genital branch of the genitofemoral nerve
Describe the path of the testicles through the abdominal layers and into the scrotum
Testicle grabs a piece of the peritoneum, then passes through and grabs the transversalis fascia, passes through (but does not grab) the transversus abdominis, passes through and grabs the internal oblique muscle, passes through and grabs the external oblique muscle, passes through and grabs Scarpa’s fascia, and enters a pocket of skin which forms the scrotum.
What gives rise to the iliopubic tract?
Where do we find the iliopubic tract?
Transversalis fascia.
Paralleling, but deep to, the inguinal ligament.
What forms the posterior wall of the deep inguinal ring, middle third of the inguinal canal, and superficial ring?
Transversalis fascia forms the posterior wall of the deep inguinal ring and middle third of the inguinal canal.
The posterior wall of the superficial ring is the conjoint tendon, as well as the reflected inguinal ligament.
What abdominal layer gives rise to the external spermatic fascia?
External oblique
To what does the lateral crus attach?
The pubic tubercle.
To what does the medial crus attach?
The pubic crest
What abdominal layers give rise to the scrotum?
Skin and Scarpa’s fascia (becoming Dartos fascia in the scrotum).
Where do the gonadal arteries come from?
The aorta on the right – and the left renal artery on the left.
What abdominal layer gives rise to the cremasteric fascia and cremaster muscle?
The internal oblique
Which nerve passes through the superficial inguinal ring, but does not pass through the deep inguinal ring?
The illioinguinal nerve
What is a vericocele?
Where does it usually occur, and why?
A fullness of the scrotum, variable in size, due to a backing up of blood into the pampiniform plexus of the testicle.
Usually occurs in the left scrotum, because the pampiniform plexus of the left scrotum drains into the left renal artery – which can become compressed.
What vessel gives rise to the cremasteric artery?
The inferior epigastric artery
What forms of the anterior wall of the deep inguinal ring, middle third of the inguinal canal, and superficial ring?
The anterior wall of the deep inguinal ring is formed by the lateral crus of the aponeurosis of the external oblique and the aponeurosis of the internal oblique.
The anterior wall of the middle third of the inguinal ligament is formed by the lateral crus and intercrural fibers of the external oblique.
The anterior wall of the superficial inguinal ring is formed by the aponeurosis of the external oblique, which continues onto the spermatic cord as external spermatic fascia.
What testicular layer is given rise to by the peritoneum?
The tunica vaginalis (parietal and visceral)
