Inguinal canal and spermatic cord

Question 1

What are the layers of the abdominal wall from outside in?

Answer 1

Skin - superficial fascia (fatty campers fascia followed by thin membranous scarpas fascia) - external oblique - internal oblique - transversus abdominis - transversalis fascia - parietal peritoneum - visceral peritoneum

Question 2

What are the 3 key pelvic ligaments and where do they span?

Answer 2

Inguinal lig - from ASIS to pubic tubercle

Pectineal lig - along pectineal line of pubic bone

Lacuna lig - connects inguinal and pectineal ligs

Question 3

What is the inguinal canal and what structures does it carry in males and females?

Answer 3

It is an opening/passage in the lower abdominal wall that is approx 4cm long in adults. In males this carries the spermatic cord and associated structures (eg ilioinguinal nerve) and in females it carries the round ligament of the uterus + ilioinguinal nerve.

Question 4

What is the advantage of the oblique nature of the inguinal canal?

Answer 4

The inguinal canal is an oblique passage instead of a direct one in order to prevent the contents of the abdominal cavity slipping through into the pelvic cavity (herniation).

Question 5

What two openings does the inguinal canal extend between?

Answer 5

Deep inguinal ring (an oval deficiency/opening in the transversalis fascia) and the superficial ring (a triangular opening/deficiency in the external oblique aponeurosis).

Question 6

Where in relation to the pubic tubercle is the superficial inguinal ring?

Answer 6

Superior and lateral to the pubic tubercle

Question 7

Where in relation to landmarks is the deep inguinal ring?

Answer 7

Halfway between ASIS and the pubic tubercle. About 1-2cm superior to the inguinal ligament. Lateral to the inferior epigastric artery.

Question 8

What do each of the layers of the abdo wall contribute to the spermatic cord?

Answer 8

Transversalis fascia - contributes to cord by forming internal spermatic fascia
Transversus abdominis - loops over the top of the spermatic cord so does not contribute
Internal oblique - contributes to cord by forming the cremasteric muscle
External oblique - contributes to cord by forming external spermatic fascia

Question 9

What is the action of the cremasteric muscle in males?

Answer 9

Draws the testes up toward the body to keep them warm when its cold and protected when in danger

Question 10

What is the inguinal ligament made from?

Answer 10

The rolled edge of the external oblique muscle

Question 11

What are the boundaries of the inguinal canal? (Post, ant, roof and floor)

Answer 11

Post = Transversalis fascia and a lil common tendon (transversalis fascia + internal oblique) medially 
Ant = External oblique aponeurosis + a lil internal oblique
Floor = inguinal lig and a lil lacuna lig medially 
Roof = transversus abdominis and internal oblique

Question 12

What is hesselbachs triangle?

Answer 12

A weakening in the lower abdo wall just medial to the inguinal lig. It is formed by the lateral edge of rectus abdominis, the inguinal ligment and the inferior epigastric artery. It is a common site for direct hernias. The superifical ring of the inguinal canal is found within this triangle.

Question 13

What travels in the spermatic cord?

Answer 13

Vas deferens + artery to vas deferens
Cremasteric muscle + artery to cremasteric muscle
Testicular artery
Pampiniform plexus (venous drainage of the testes)
Lymphatics
Tunica vaginalis
Sympathetic nerves from the testicular plexus
Genito branch of genitofemoral nerve

Question 14

What does the processus vaginalis become once it has pinched off from the peritoneum?

Answer 14

Tunica vaginalis

Question 15

What are two things that are different about the ilioinguinal nerve than the other structures that pass through the spermatic cord?

Answer 15

It dosent run through the deep inguinal ring - it pierces the inguinal canal through the roof (internal oblique).

It dosent actually travel in the spermatic cord - it travels alongside the spermatic cord down into the scrotum.

Question 16

What is testicular torsion?

Answer 16

Where the spermatic cord twists around itself which cuts off its blood supply. This is a medical emergency as there is only a window of 6 hours to save the testes.
It is characterised by onset of acute and severe pain in the testes but can radiate into the lower abdo.

Question 17

What is the cremasteric reflex?

Answer 17

Stroking the inner medial thigh will cause activation of the sensory fibres of the genitofemoral nerve and this will then activate the motor nerves of this branch causing the cremasteric muscle to contract and this will raise the testes of the side of stroking to life up.

Question 18

What are the two main types of inguinal hernia and what is different between them?

Answer 18

Direct - herniation pierces directly through a weakening in the abdo wall of the inguinal canal eg hesselbachs triangle

Indirect - herniation goes through the entirety of the inguinal canal

Question 19

What age group is each type of inguinal hernia most common in and why?

Answer 19

Indirect - juveniles because their inguinal canals and not yet oblique (straight passage from deep inguinal ring to superficial)

Direct - older men as abdo wall gets weaker with age

Question 20

How can you check a lump in the groin is a hernia?

Answer 20

Cough impulse and reducibility test

Get them to cough and if the lump bulges out under the pressure it is a hernia

Question 21

How can you tell if direct or indirect?

Answer 21

Put finger over superifical inguinal ring and repeat cough test - of the bulge no longer appears then it is indirect.