Inguinal Canal Flashcards
What is the Dartos tunic in the scrotum continuous with?
The membranous (Scarpa’s) fascia of the anterior abdominal wall.
What does the membranous (Scarpa’s) fascia of the anterior abdominal wall merge with at the inguinal ligament?
The fascia lata (deep fascia of the thigh).
What does the ilioinguinal nerve run along?
It runs along the inguinal border and down with the spermatic cord.
Where are the ilioinguinal and iliohypogastric nerves located?
Between the external and internal obliques.
What is the location of the neurovascular plane of the anterior abdominal wall?
Between the internal oblique and the transversus abdominus.
What is the conjoint tendon?
The conjoint tendon is formed by the arching fibers of the transversus abdominus and the medial fibers of the internal oblique.
What do the inferior epigastric arteries come off of?
The external iliac arteries.
What do the superior epigastric arteries come off of?
The internal thoracic artery.
What does the inguinal ligament extend from?
From the ASIS to the pubic tubercle.
What is the inguinal ligament continuous with?
The aponeurosis of the external oblique.
Where did the testes begin embryologically and what does this mean about their mature position?
The testes began as part of the posterior abdominal (retroperitoneal) wall and had to descend into the scrotal sac.
What is the gubernaculum?
A fibrous CT that connects the testes to the floor of the scrotal sac. Is what pulled the testes into the sac during development.
Where did the testes first enter the anterior abdominal wall?
At the deep inguinal ring located in the transversalis fascia.
Where did the testes exit?
The superficial inguinal ring located in the external oblique.
What layers of the anterior abdominal wall did the testes “pick up” to form the spermatic cord?
The transversalis fascia, internal oblique, and external oblique. They missed the transversus abdominus due to its overarching fibers.
What derived the internal spermatic fascia of the spermatic cord?
The transversalis fascia.
What derived the middle/cremasteric muscle/fascia of the spermatic cord?
The internal oblique.
What derived the external spermatic fascia of the spermatic cord?
The external oblique.
What does the ilioinguinal nerve run along within the spermatic cord?
It runs superficial to the cremasteric fascia/muscle.
What nerve is contained deep to the internal spermatic fascia alongside the ductus deferens, etc.?
The genital branch of the genito-femoral nerve.
What nerve runs between the middle/cremasteric fascia and the external spermatic fascia?
The ilioinguinal nerve.
What is the cremasteric reflex?
Touching the ipsilateral inner thigh to invoke raising of the testes (cremaster muscle).
What is the afferent limb of the cremasteric reflex?
The ilioinguinal nerve (why touching the inner thigh will initiate the reflex).
What is the efferent limb of the cremasteric reflex?
The genital branch of the genito-femoral nerve.
What spinal cord level does the cremasteric reflex asses?
L1
What is the gubernaculum attached to besides the scrotum?
The parietal peritoneum.
What happens to the peritoneum during the descent of the testes due to its attachment to the gubernaculum?
During the descent of the testes a sheath of peritoneum is pulled into the scrotum.
What happens to the peritoneal sheath?
It closes off and forms the tunica vaginalis surrounding the testes.
What happens when the peritoneal sheath doesn’t close off?
It forms an open pathway from the abdominal cavity into the scrotum, predisposing to inguinal hernias.
What happens when the peritoneal sheath incompletely closes off?
It forms a fluid filled hydrocele that can create a potential weakness for inguinal hernias.
What is the medial border of the inguinal triangle?
The lateral border of the rectus abdominus.
What is the lateral border of the inguinal triangle?
The inferior epigastric vessels.
What is the inferior border of the inguinal triangle?
The inguinal ligament.
What defines an indirect inguinal hernia?
When the loop of bowel enters the deep inguinal ring and the inguinal canal.
What defines a direct inguinal hernia?
When the loop of bowel exits through a tear in the anterior abdominal wall (traumatic injury).
How can a direct inguinal hernia be differentiated from an indirect inguinal hernia?
An indirect inguinal hernia will occur lateral to the inferior epigastric vessels while a direct will occur within the inguinal triangle (medial to the inferior epigastric vessels).
What does the round ligament of the uterus travel though?
It originates from the uterus, travels through the inguinal canal (female equivalent to the spermatic cord) and will attach to the skin of the labia majus.
Why are inguinal hernias less common in females?
Because the round ligament of the uterus is not as large as the spermatic cord, plus the inguinal ligament is wider in females (path of least resistance).
What forms the fascia of the femoral sheath?
The transversalis fascia and the iliacus fascia.
What are the contents of the femoral sheath from lateral to medial?
The femoral nerve, artery, vein, and lymphatics (NAVL).
What is important about the femoral artery, vein, and lymphatics?
They are contained within their own separate compartments within the femoral sheath.
What does the femoral canal convey and what does it predispose to?
The femoral canal is where the lymphatics are contained within the femoral sheath, but it also provides a path for femoral hernias.
What is the saphenous opening?
An opening in the fascia lata that allows the great saphenous vein to drain into the femoral vein.
What is clinically relevant about the saphenous opening?
It is an additional structure that bowel can herniate through in a femoral hernia.
