Inguinal Canal Flashcards
What are the two Embryological structures involved in the area of the genitals that we need to understand? Why are they significant?
Gubernaculum and Processus Vaginalis
- Gubernaculum is a structure that attaches to the inferior of developing Kidney and anterior aspect of wall that becomes scrotum.
- Processus Vaginalis is an invagination of the peritoneum just anterior to the gubernaculum.
Both are responsible for the descent of the testes.
What are results of Processus Vaginalis failing to close?
Congenital/Acquired Inguinal Hernias and Hydroceles.
Hydrocele: Fluid builds up in tunica vaginalis
Hernia: Loop of Intestine is herniated into the scrotal sac.
What forms the Inguinal Ligament?
Lower border of the Aponeurosis of the External Oblique Muscle (EOM)
What is the Inguinal Canal?
A canal extending from Deep Inguinal ring (Internal) and Superficial Inguinal ring (External). Note that the curvature of the Inguinal Ligament defines the border of the Superficial Inguinal Ring.
4 cm long.
Define the walls of the Inguinal Canal.
Anterior Wall, Floor: EOM
Roof: IOM and TA
Posterior Wall: Falx Inguinalis, Transversalis Fascia
Falx Inguinalis (fusion of the aponeuroses of IOM and TA)
Where is the weakest point in the Inguinal Canal?
Posterior wall, lateral aspect.
This region of the Posterior wall contains ONLY the Transversalis Fascia. A Direct Inguinal Hernia can occur here.
Describe the Inguinal Mechanism.
Aponeuroses of 3 Flat Muscles form arcade with three arches.
A = EOM Aponeuro.
B = IOM; Muscular Arch
C = TA; Muscular Arch
During Contraction: A remains open.
B and C contract.
Narrowing of the canal will reduce likelihood of hernia. EOM can contract to make this happen as well.
What is the Cremaster Reflex?
Elicited by lightly stroking skin of inner thigh. Cold hands makes this more active, ESPECIALLY IN CHILDREN, so warm hands before testing!
Testes will retract due to this reflex (think of the story of American soldiers in Vietnam)
What is the Pampiniform Plexus of Veins?
8 to 12 veins that surround the Testicular artery and Vas Deferens (this is below the Inguinal Ring). They merge as you ascend into 2-4 veins (Between Deep and Superficial Inguinal Rings) , and then will fuse again to form the Testicular veins on either side (Over Psoas Major(?)).
They are involved in thermoregulation(?)
Where do the Testicular Veins drain?
Right -> IVC
Left -> Left Renal Vein
What are the constituents of the Spermatic Cord?
3 Fasciae
- External Spermatic Fascia: EOM
- Cremasteric Fascia: IOM
- Internal Spermatic Fascia: Transversalis Fascia
3 Arteries
- Cremasteric Artery (between Internal and Cremasteric)
- Artery of Vas Deferens (interior of Cord)
- Testicular Artery (Interior of Cord)
3 Veins
- Same as arteries, same locations as well
3 Nerves
- Ilioinguinal Nerve (between External and Cremasteric)
- Genital Branch of Genitofemoral (Between Cremasteric and Internal)
- Sympathetics (Interior of Cord)
What is Testicular Torsion?
twisting of Spermatic Cord; can block blood supply to testes and cause irreversible damage within a few hours.
Bell-clapper deformity/Torsion.
What can be mistaken as the Inguinal Ligament?
Iliopubic tract: a thickening of the Inferior margin of the transversalis fascia over the Iliopsoas muscle.
What are the borders of the Femoral Ring?
Superior: Inguinal Ligament
Inferior: Pectineal Ligament (of Cooper)
Lateral: Fascia subdividing the femoral sheath by Femoral Vein)
Medial: Transversalis Fascia, TA Aponeurosis or Iliopubic Tract
What is the Femoral Sheath?
An extension of the Transversalis Fascia and Iliac Fascia that surround 3 compartments for the 3 Femoral Vessels:
- Femoral Artery
- Femoral Vein
- Femoral Canal (Gland of Cloquet)
