Lecture 8: Inguinal Canal and Spermatic Cord Flashcards
What are the 9x layers of the abdominal wall?
- Skin
- Camper’s Fatty Superficial fascia
- Scarpa’s Membranous Superficial fascia
- External oblique
- Internal Oblique
- Transversus Abdominus
- Transversalis Fascia
- Extraperitoneal Fascia
- Partial Perotineum
Key Pelvic Landmarks
ASIS: termination of illiac spine AIIS Pectineal Line Pubic Tubercle, Crest (posterior medial) and Symphysis (Linea Alba) Inguinal Ligament
Clinical relevance of Pubic Tubercle
Can palpate
Useful if want to diagnose hernia’s
Relationship b/w Pubic Crest and Tubercle
Pubic Crest is PosterioMedial to Pubic Tubercle
3x Key Pelvic Ligaments
- Inguinal Ligament
- Pectineal Ligament
- Lacunar Ligament
Function of Pelvic ligaments: Attach suture during Inguinal hernia repairs. Will hold as all 3x are strong and robust ligaments
Inguinal Ligament
ASIS to Pubic Tubercle
Rolled free edge of External Oblique Aponeurosis
Pectineal Ligament
Pectineal line to Pubic bone
Lacunar Ligament
connects Inguinal and Pectineal Ligament
- sweeps horizontally onto pubic bones
- essentially a continuation of Inguinal ligament
Clinical: Sharp edges which thing scan get trapped against
Inguinal canal
Canal through which Pelvic Inguinal Ligament passes through (Lower part of the abdominal wall)
Oblique passage –> helps prevent herniation (of abdominal contents)
Superficial Inguinal Ring Deep Inguinal Ring (4 cm in adults) (runs superficial –> deep)
Inguinal Canal in Males and Females
Male Inguinal Canal: Has Spermatic cord carries structures too/from abdomen testes 2. Illioinguinal nerve alongside (in canal not in cord)
Female Inguinal Canal: 1. (Uterine) Round Ligament from pelvis Labia majora 2. Ilioinguinal nerve
Ilioinguinal nerve
Contained in Inguinal Canal in both males and female
Males: In Inguinal canal, Ontop (not inside) Spermatic Cord
- DOES NOT “travel through” inguinal canal technically –> Misses DIR and instead Pierces Internal Oblique Roof (of the canal) –> runs outside spermatic cord –> Exits at SIR
- therefore does not go through DIR
- Provides sensation around pubic region
Superficial Inguinal Ring
Aponeurosis of External Oblique –> Triangular Shaped
SuperioLateral to Pubic Tubercle
Crura= Margins –> Medial and Lateral Crus –> create the spermatic cords’ (within male inguinal canal) External Spermatic Fascia
- Sometimes contains Transverse fibres for support
Deep Inguinal Ring
Transversalis Fascia Oval opening
Location:
1. Lateral to Inferior Epigastic artery.
2. Just past Mid-Inguinal Point (1.5- 2cm superior) –> 1/2 Way b/w ASIS and Pubic Symphsis
Creates Internal Spermatic Fascia of male Spermatic Cord –> Round Ligament in females
Transversus Abdominus and Internal Oblique
Located b/w Superficial and Deep Inguinal Ring
1. Transversus Abdominus: Doesnt contribute to spermatic fascia
2. Internal Oblique: Creates Cremasteric Muscle
- part of spermatic cord. comes of the scrotum
- helps draw testes towards body
Combined: Transversus Abdominus + Internal Oblique –> combine to form a CONJOINT TENDON
- on Pubic CREST / Pectineal Line
Borders of the Inguinal Canal
Anterior Wall: (Deep I. R) 1. External Oblique aponeurosis 2. Internal Oblique Lateral 1/3 Floor (ligaments for solidarity --> used for suturing herniation) 1. Inguinal ligament (rolled free edge of ext. oblique aponeurosis) 2. Lacunar Ligament Roof: 1. Internal Oblique 2. Transversus Abdominus Posterior Wall: (Superficial I. R) 1. Transversalis Fascia 2. Conjoint Ligament (medial 1/3)
Draw Inguinal Canal diagram
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Hesselback’s (Inguinal) Triangle
Sides:
- Inferior Epigastric Artery
- Inguinal Ligament
- Rectus Abdominus (lateral border)
- Site of Direct Hernia (pushing through abdominal wall)
- Deep Inguinal ring located superiolateral
- Associated with weak anterior wall of Superficial Inguinal Ring
Spermatic Cord
Collection of structures, within male Inguinal canal, DIR (deep inguinal ring) testes
3x concentric layers of fascia. all derived from Anterior abdominal wall
- layers are continuous w. scrotum
- pushes through abdominal wall –> 3x concentric continuous layers (take a tubular sheath from each layer)
Spermatic Cord arises from Processus Vaginalis (a Peritoneal Diverticulum)
- Peritoneal (inner most abdominal layer) out-pouching pinches off –> forms closed sac –> remnant is newly named Tunica vaginalis
Layers of the Spermatic Cord
- External Oblique (SIR) –> External Spermatic Fascia
- Internal Oblique –> Cremaster Muscle
- Transversus Abdominus (NO COVERING - hooks around)
- Transversalis Fascia (DIR) –> Internal Spermatic Fascia
Scrotal Remnant
Innermost layer of abdominal cavity being pushed downwards by descending spermatic cord (Peritineum) –> eventually pinches off and forms a closed sac remnant structure –> Tunica Vaginalis
Contents of the Spermatic Cord
3x Layers:
- 3x Arteries: a) Testicular (L2) b) Vas deferens/Deferential c) Cremasteric
- 3x Nerves: a) Genital branch of Gentiofemoral (L1&2) b) Sympathetic nerves (from testicular plexus) c) Illioinguinal nerve L1 (within canal, ontop of cord)
- 3x Other structures: a) vas deferens b) Lympahtics c) Tunica vaginalis
- 1x Venous plexuses: Pampiniform plexus (runs entire way down plexus)
Why are the Testes external?
Testes external so can be relatively colder than body temp –> VENOUS PLEXUS heat exchange/dissipation –> optimum enviro. for sperm production
Testicular Artery
Abdominal aorta La
Supplied Testes and Epididymis
Vas deferens
Muscular duct
Transport spermatozoa from Epididymis Urethra
Artery of vas deferens
Accompanies Vas Deferens
IMPORTANT to be considered in order to avoid damaged during VASECTOMY
Pampiniform Plexus
Temperature regulation
Forms a single vein in DIR
Genital branch of Gentiofemoral nerve
Motor and sensory
Innervates:
1. Cremasteric Muscle
2. Skin of the Scrotum –> Therefore gentiofemoral nerve is located b/w External Spermatic Fascia + Cremasteric Muscle
Lymphatics in scrotal area
Drain to Para-aortic nodes in L2
- this is the origin of testicular arteries
Testicular Torsion
spermatic cord twists around –> cuts off blood supply –> ischaemia
Surgical emergency in 6 hours
Symptoms of Testicular Torsion
Acute and severe testicular pain (L1-2) –> Loin-Groin (referred to groin + lower abdomen)
- similar symptoms to similar pathologies in anatomical region (epididimytis)
Absent/Decreased cremasteric reflex
Nausea/ Vomitting
Redness/Pyrexia (inflammation)
Is there any predisposition to suffering from testicular torsion/decreased cremasteric reflex?
Pubinaculum is involved in testicular descent to scrotum –> Anchors testes to the floor of the scrotum
However: Some people are less anchored –> relatively freer to move –> greater risk of testicular torsion
Normal Cremasteric reflex
(Juvenile)
- Stroke Superiomedial thigh –>
- Stimulation of sensory fibres of:
a) Femoral branch of genitofemoral nerve (L1-2)
b) Illioinguinal nerve (L1-2) - Stimulation of motor fibres of: Genital branch of gentiofemoral nerve (which innervates cremasteric muscle and skin of scrotum)
- Contraction of Cremasteric muscle –> on Ipsilasteral (same) side –> Testes raised
Cremasteric reflex if testicular torsion has occured
Cremasteric muscle isnt present
Confirming Occurance of testicular torsion:
- Superiomedial stroking stimulation of reflex isnt Infallible (Note: cremasteric reflex absence doesnt guarantee testicular torsion, and vice versa)
- Ultrasound confirmation shows lack of blood flow –> very reliable
Note: Testicular Torsion decreases blood Flow > doesnt occur in Epididimytis (therefore US can distinguish b/w the two)
6 hour window of opportunity –> after this chance of saving testis decreases significantly
