Flashcards in Lecture 8 Deck (47):
What is the most superficial layer?
What is the layer underneath the skin layer?
This layer is split up into two:
1. Fatty Superficial Fascia (Camper’s).
2. Membranous Superficial Fascia (Scarpa’s) - tend to find this fascia beneath the umbilicus.
What is the layer underneath the deep fascia?
The three muscle layers:
1. External oblique (infero-medial).
2. Internal oblique (supero-medial).
3. Transversus abdominis.
What is the layer underneath the muscle layers?
What is the layer underneath the transversalis fascia?
What are the key bony landmarks?
2. Pubic symphysis.
3. Pubic tubercle - palpate with thumbs.
4. Pubic crest.
5. Pectineal line.
Where does the inguinal ligament run from?
ASIS to pubic tubercle - it is formed from rolled edge of external oblique aponeurosis.
Where does the lacunar ligament run from?
This ligament connects the inguinal and pectineal ligament - sharp edge (things can get trapped in here).
Where does the pectineal ligament run from?
Pectineal line of the pubic bone.
Describe the inguinal canal?
It is an oblique passage through the lower part of the abdominal wall - the oblique nature of the canal helps to prevent herniation of abdominal contents.
How long is the inguinal canal?
In adults it is around 4cm long.
Where does the inguinal canal extend from?
Deep inguinal ring to the superficial inguinal ring.
What does the inguinal canal carry in males?
It carries structures to and from the testis and abdomen via the spermatic cord (and ilioinguinal nerve - not involved within the psermatic cord).
What does the inguinal canal carry in females?
It carries the round ligament of the uterus from the pelvis to the labia majora (and ilioinguinal nerve).
Describe the superficial inguinal “ring” (SIR)?
It is a triangular defect in the aponeurosis of the external oblique.
Describe it’s reference to the pubic tubercle?
It is superior and lateral to the pubic tubercle.
What do the margins (crura) of the SIR give rise toE?
External spermatic fascia (of the spermatic cord).
Describe the deep inguinal “ring” (DIR)?
It is an oval opening formed in the transversals fascia.
Describe the landmarks of DIR?
DIR is halfway between ASIS and pubic symphysis (mid-inguinal point). It is 1.5-2cm above the inguinal ligament. It is lateral to the inferior epigastric artery.
What do the margins (crura) of the DIR give rise to?
Internal spermatic fascia (spermatic cord in men and round ligament fascia in women).
What is between SIR (transversalis fascia) and DIR (external oblique)?
There are two more muscles that help to form the inguinal canal and spermatic fasciae:
1. Transversus Abdomens: This does not contribute to spermatic fascia.
2. Internal Oblique: This gives rise to the muscular layer - cremasteric muscle (of spermatic cord).
These two muscles will join medially to form a common tendon which attaches onto the pubic crest/pectineal line = Conjoint Tendon.
What is the anterior inguinal canal borders?
Aponeurosis of external oblique muscle and internal oblique muscle (in lateral 1/3).
What is the floor inguinal canal borders?
Inferior rolled edge of external oblique aponeurosis (inguinal ligament) and lacunar ligament (medial).
Looking from superior view, the inguinal ligament runs from AISS to Pub.Tub.
What is the roof inguinal canal borders?
Fibres of internal oblique and transverses abdominis.
What is the posterior inguinal canal borders?
Transversalis fascia and conjoint tendon (medial 1/3).
Describe Hesselbach’s (Inguinal) Triangle?
This is a site where you typically get direct hernia. It pushes through weakened abdominal wall. It corresponds to weak anterior wall (superficial inguinal ring). It is the triangle between: inferior epigastric artery, inguinal ligament and lateral border of rectus abdominus.
What is the spermatic cord?
This is a collection of structures which pass along the male inguinal canal to the testis. There are 3 concentric layers of fascia derived from the anterior abdominal wall. It begins at the deep inguinal ring and ends at the testis.
Describe the spermatic cord layers?
The spermatic cord arises from a peritoneal diverticulum called the processes vaginalis - it pushes through the abdominal wall taking a tubular sheath from each layer:
1. Transversalis fascia (DIR) = Internal Spermatic Fascia.
2. There is no covering form the transverses abdominis.
3. Internal Oblique = Cremaster muscle.
4. External Oblique (SIR) = External Spermatic Fascia.
Peritoneal out-ouching eventually pinches off leaving a closed off sac - tunica vaginalis (as a remnant).
What are the arteries in the spermatic cord?
1. Testicular artery - branches off at L2 from the abdominal aorta.
2. Artery of Vas Deferens (Deferential artery).
3. Cremasteric artery.
What are the nerves in the spermatic cord?
1. Genital branch of genitofemoral nerve - L1-2.
2. Sympathetic nerves - from testicular plexus.
3. (Ilioinguinal nerve - L1) - (Doesn’t travel in the cord - piercing through roof of canal).
What are the three other structures in the spermatic cord?
1. Vas Deferens.
3. Tunica Vaginalis.
What is the venous plexus of the spermatic cord?
What does the testicular artery supply?
Testes and epididymis.
What is the Vas Deferens?
It is the muscular duct which transports spermatozoa from the epididymis to the urethra.
Describe the vas deferens artery?
it accompanies vas deferens and is important for vasectomy (often damaged during vasectomy).
What does the paminiform plexus do?
It helps with temperature regulation - it forms a single vein at the deep inguinal ring.
What does the genital branch of the genitofemoral nerve innervate?
It innervates the cremaster muscle (M) and skin of scrotum (S) - why it sits outside the cremaster muscle.
Where do the lymphatics drain?
They drain to the para-aortic nodes at L2 (origin of the testicular arteries).
What is testicular torsion?
This is where the spermatic cord twists round, cutting off the blood supply - causing ischaemia. Surgical emergency - window of 6 hours.
What are the symptoms of testicular torsion?
1. Acute and severe testicular/scrotal pain.
2. Pain is also referred to groin and lower abdomen.
3. Symptoms may be similar to other conditions affecting this anatomical region e.g. epididymitis.
4. Absent/decreased cremasteric reflex.
6. Redness and pyrexia.
Describe the cremasteric reflex?
1. Stroke the superior medial thigh.
2. This will stimulate sensory fibres of the femoral branch of genitofemoral nerve and ilioinguinal nerve (L1-2 origins).
3. This is turn stimulates motor fibres of genital branch of genitofemoral nerve - cremaster muscle contracts on ipsilateral side, raising the testis.
What happens to the cremasteric reflex if testicular torsion has occurred?
The reflex is not present (method is not infallible - if there is no reflex is does not mean that it is torsion). Ultrasound confirmation is very reliable - it distinguishes torsion from epididymitis by showing lack of blood flow to testis. There is a 6 hour window of opportunity - the chance of saving the testis drops significantly after this time.
What are the type of hernias?
1. Direct Inguinal.
2. Indirect Inguinal.
Describe inguinal hernias?
It is the protrusion of the abdominal contents through the inguinal canal.
Describe indirect inguinal hernias?
Hernias that go through the DIR and through the entirety of the inguinal canal into the scrotum within the spermatic cord. It is lateral to the inferno epigastric artery. it is often seen in juveniles - oblique passage of canal has not yet formed (DIR is overlaid by SIR). It can be a congenital defect.
Describe direct inguinal hernias?
Herniation through the weak spot in the fascia of posterior wall of inguinal canal - hesselbach’s triangle. It is medial to the inferior epigastric artery. males are 10 times more likely to have direct inguinal hernia than women. Middle aged to elderly are far more likely to get them than the young.