Lecture 4: Inguinal canal and spermatic cord Flashcards
Are the inguinal canal and spermatic cord the same thing?
Yes
Whats the origin and insertion of the inguinal ligament and whats it formed from?
Origin: ASIS
Insertion: Pubic tubercle
Formed from rolled edge of external oblique aponeurosis
What does the lacunar ligament connect?
Joins inguinal and pectineal ligament
Where is the pectinal ligament located?
Pectineal line of the pubic bone
What is the inguinal canal and its function?
Oblique passage through lower part of abdominal wall, the oblique nature helps prevent herniation of abdominal contents
What two structures does the inguinal canal extend between?
Extends from deep inguinal ring to the superficial inguinal ring
What is the inguinal canal used for in males?
Carries structures to and from the testis and abdomen via the spermatic cord (+Ilioguinal nerve)
What is the inguinal canal used for in females?
Carries round lig. of uterus and genitofemoral nerve from pelvis to the labia majora (+Ilioguinal nerve)
What is the superficial inguinal ring of the external oblique?
Triangular shaped defect in aponeurosis of external oblique
What is the surface landmark of the superficial inguinal ring?
Superior and lateral to pubic tubercle
What doe the external margins of the superficial inguinal ring give rise to?
Margins (Crura) give rise to EXTERNAL Spermatic fascia (of the spermatic cord)
What is the deep inguinal ring?
Oval opening in the transversalis fascia
What are the landmarks of the deep inguinal ring?
Landmarks:
- Halfway b/w ASIS and pubic symphysis (mid inguinal point)
- ~1cm above inguinal ligament
- Lateral to inferior epigastric artery
What does the deep inguinal ring give rise to in men and in women?
Men: Internal spermatic fascia (of the spermatic cord)
Women: Round ligament fascia
What are two additional muscles that help form the roof of inguinal canal and spermatic cord?
Transversus abdominus and internal oblique
Describe the contribution of the transversus abdominus to the inguinal canal:
Origin: Lat 1/3 of inguinal lig.
DOES NOT CONTRIBUTE TO SPERMATIC FASCIA
Describe the contribution of the internal oblique to the inguinal lig.
Origin: Lat 2/3 of inguinal lig
Gives rise to cremasteric muscle of spermatic cord
What do the transversus abdominus and internal oblique form?
Form common tendon on pubic crest / pectineal line (Conjoint tendon)
What forms the anterior wall, floor, roof and posterior wall of the inguinal canal:
Ant. wall = Aponeurosis of external oblique + Internal oblique
Floor = Inf. rolled edge of external oblique aponeurosis (inguinal lig.) + Lacunar lig. (Medial)
Roof = Fibres of internal oblique and Transversus Abdominus
Post. wall = Transversalis Fascia + Conjoint tendon
Whats the significance of the inguinal triangle?
Site of direct hernia (pushes through weakened abdo wall)
- Corresponds to weak ant. wall (Sup. ant. ring)
What creates the inguinal (hesselbachs) triangle?
Later border of rectus abdominus
Inf. epigastric art
Inguinal ligament
How many layers are in the spermatic cord and whats the significance?
3 concentric layers of fascia derived from the abdominal wall (where there are four layers….)
Begins at the deep inguinal ring, ends at testis
How does the spermatic cord form?
Arises from peritoneal diverticulum called the processes vaginalis - pushes through abdo wall taking a a tubular sheath from each layer
Describe which abdo wall layers give rise to which spermatic cord layer:
Transversalis fascia (DIR) = internal spermatic fascia Transversus abdominus = NO CONTRIBUTION Internal oblique = Cremaster muscle External oblique (SIR) = External spermatic fascia
Layers are continuous with scotum
