Gross Anatomy – Inguino-Scrotal Region
Regions
Inguinal Scrotal
Inguinal ligament Scrotum
Iliopubic Tract Testis
Subinguinal Space Clinical Anatomy
• Cremasteric Reflex
• Hydrocoele
• Haematocoele
• Torsion of Spermatic Cord
• Spermatocoele, Epididymal Cyst
• Vestigial Remnants of Embryonic
Genital Ducts
• Varicocoele
• Cancer of Testis, Scrotum
Inguinal Canal
Spermatic Cord
Inguinal, Hesselbach Triangle
Dermatome
Clinical Anatomy
• Inguinal Hernias
• Cysts, Hernias of Canal, Nuck
Inguinal Region
Extend between
• ASIS
• Public Tubercle
Migration of Testis out of Abdomen into Perineum
(Through Inguinal Canal)
Inguinal Ligament, Iliopubli c Tract
Extends between ASIS, Public Tubercle
Form Bilaminar Anterior (Flexor) Retinaculum of Hip Joint
Retinaculum Spans the Subinguinal Space
Myopectineal Orifice (Site of Inguinal, Femoral Hernias)
Innate Weakness in Body Wall in Region of Groin
Inguinal Ligament
Thickened/Dense
Underturned
Inferior margin of Aponeurosis of External Oblique Muscle
Amount
of Fibers Part of Fibers Direction Attachment
Ligament
Formed
Most Medial Fibers Medially Public Tubercle Inguinal
Ligament
Some Deeper
Fibers
Pass
Posteriorly
Superior Pubic
Ramus Lateral to
Public Tubercle
Lacunar
Ligament
(Gimbernat)
The Most
Lateral
Fibers
Run along
Pecten Pubis
Pectineal
Ligament
(Cooper )
Some Superior
Fibers
Fan
Upward
Cross Linea Alba to
blend with
Lower Fibers of
Contralateral
External Oblique
Aponeurosis
Reflected
Inguinal
Ligament
Iliopubi c Tract
Thickened Inferior Margin of Transversalis Fascia
Runs Parallel, Posterior (Deep) to Inguinal Ligament
Reinforces Posterior Wall, Floor of Inguinal Canal
Useful Landmark during Laparoscopic Hernia Repair
Male Female
Most Groin Hernias Pass Superior to
Iliopubic Tract (Inguinal Hernias)
Most Groin Hernias Pass Inferior to
Iliopubic Tract (Femoral Hernia)
Subinguinal Space
Passageway connecting Abdominopelvic Cavity → Lower Limb
Lies between
• Inguinal Ligament (Deep Surface)
• Iliopubic Eminence
Divided into 2 Compartments/ Lacunae
(by a Thickening of Iliopsoas Fascia) (Iliopectineal Arch)
Lacuna Position Structures
(Passing Through, Located in Lacuna)
Muscular Lateral to Arch Iliopsoas Muscle
Femoral Nerve
Lateral Cutaneous Nerve of Thigh
Vascular Medial to Arch Pectineus Muscle
External Iliac Artery, Vein
(Forming Femoral Artery, Vein)
Femoral Ring
Lymphatic Vessels
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Femoral Ring
Oval Ring
Base/ Proximal Opening of Femoral Canal
Closed by Extraperitoneal Fatty Tissue that
forms Femoral Septum (Transversely Oriented)
Abdominal Surface of Septum is covered by Parietal Peritoneum
Femoral Septum is Pierced by Lymphatic Vessels Connecting
• Inguinal Lymph Nodes
• External Iliac Lymph Nodes
Boundaries
Lateral Vertical Septum between
• Femoral Canal
• Femoral Vein
Posterior Superior Ramus of Pubis
Covered by Pectineus Muscle, Fascia
Medial Lacunar Ligament
Anterior Medial Part of Inguinal Ligament
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Inguinal Canal
Oblique, Inferome dially directed passage (≈ 4 cm long)
through Inferior part of Anterolateral Abdominal Wall
Lies Parallel, Superior (2-4cm) to Medial Half of Inguinal Ligament
Formed in relation to Descend of Testis during Foetal Development
Development of Male Inguinal Canal
Testis develop in Extraperitoneal Space
(in Superior Lumbar Region of Posterior Abdominal Wall)
Male Gubernaculum Processus Vaginalis
Fibrous cord conne cting
• Primordial Testis
• Anterolateral Abdominal Wall
(Site of Future Deep Ring of
Inguinal Canal)
Peritoneal Diverticulum
Transverses Developing Inguinal
Canal
Carries Muscular, Fascial Layers of
Anterolateral Abdominal Wall
(Before it enters the Primordial
Scrotum)
Development of Male Inguinal Canal
Age Events
12 Weeks Testis is in the Pelvis
28 Weeks Testis lies close to Developing Deep Inguinal Ring
Begins to Pass through Inguinal Canal
Takes ≈ 3 Days
32 Weeks Testis enters the Scrotum
6th
Month Stalk of Processus Vaginalis Obliterates (Normally)
Distal Saccular part of Processus Vaginalis
forms Tunica Vaginalis Testis
(Serous Sheath of Testis, Epididymis)
As Ductus Deferens, Nerves, Vessels Descend
(Ensheathed by Mucolofascial Extension of Anterolateral Abdominal Wall)
Inguinal Canal
Male Female Adult Infants
Wider Narrower Longer
↑ Oblique
Shorter
↓ Oblique
Superficial Rings in Infants lie almost directly Anterior to Deep Rings
Development of Female Inguinal Canal
Age Events
2 Months Ovaries develop in Superior Lumbar Region of Posterior
Abdominal Wall
Female Gubernaculum (Fibrous Cord Connecting Ovary,
Primordial Uterus to Developing Labium Majus)
15 Weeks Migrate to Lateral Wall of Pelvis
Processus Vaginalis transverses the Tranversalis Fascia
(at site of Deep Ring) Forming Inguinal Canal
Protrudes into Developing Labium Majus
Mature Processus Vaginalis Degenerates
Female Gubernaculum Postnatally become
• Ovarian Ligament (between Ovary, Uterus)
• Round Ligament of Uterus
(between Uterus, Subcutaneous Tissue of Labium Majus)
Ovaries do not Descend to Inguinal Region
(because of Attachment of Ovarian Ligament to Uterus)
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Boundaries of Inguinal Canal
Boundary Lateral 3rd
(Deep Ring)
Middle 3rd
Medial 3rd
(Superficial Ring)
Posterior
Wall
Transversalis
Fascia
Transversalis Fascia Conjoint Tendon
(Inguinal Falx)
Reflected Inguinal
Ligament
Anterior
Wall
IO Aponeurosis of EO
(Lateral Crus,
Intercrural Fibers)
Aponeurosis of EO
(Intercrural Fibers)
with Fascia of EO
continuing onto
cord as External
Spermatic Fascia
Lateral Crus of
Aponeurosis of EO
Roof Transversalis
Fascia
Musculoaponeurotic
Arches of IO, TA
Medial Crus of
Aponeurosis of EO
Floor Iliopubic Tract Inguinal Ligament Lacunar Ligament
Conjoint Tendon (I nguinal Falx)
Merging of Pubic Attachments
of IO, TA Aponeuroses
into a Common Tendon
Deep (Internal) Inguinal Ring
Entrance to Inguinal Canal
Site of Outpouching of Transversalis Fascia
1.25cm Superior to Middle of Inguinal Ligament
Lateral to Inferior Epigastric Artery
Beginning of Evagination in Transversalis Fascia
(Forming an Opening through which Ductus Deferens/ Round Ligament of
Uterus, Gonadal Vessels pass to enter Inguinal Canal)
Transversalis Fascia continues into Canal
(Forming Innermost covering (Internal Fascia) of Structures Transversing Canal)
Contents of Inguinal Canal
Male Female
Spermatic Cord Round Ligament of Uterus
Ilioinguinal Nerve
(Outside the Cord, Inside the Canal)
Ilioinguinal Nerve
(Outside the Cord, Inside the Canal)
Inguinal Canal
Superficial (External) Inguinal Ring
Exit from Inguinal Canal
Slitlike opening between diagonal fibers of Aponeurosis of External Oblique,
superolateral to Pubic Tubercle (Through which Spermatic Cord/ Round
Ligament of Uterus Emerge from Inguinal Canal)
Lateral, Medial Margins of Superficial Ring formed by Split in Aponeurosis are
called Crura
Lateral Crus Medial Crus
Pubic Tubercle Pubic Crest
Fibers arising from Inguinal Ligament Lateral to Superficial Ring Arch
superolaterally to Superficial Ring
Intercrural Fibers – Help Prevent Crura from Spreading Apart
(Keep the “split” in Aponeurosis from E xpanding)
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Spermatic Cord
Suspends Testis in Scrotum
Begins Ends
Deep Ring
(Lateral to Inferior Epigastric Vessels)
Scrotum
(Posterior Border of Testis)
Fascial Extensions of Abdominal Wall
Transversalis Fascia IO Muscle, Fascia EO Aponeurosis
Internal Spermatic
Fascia
Cremasteric
Muscle, Fascia
External Spermatic
Fascia
Forms the Fascial Coverings of Spermatic Cord
Layers of Anterior Abdominal Wall, Scrotum, Spermatic Cord
Innervation of Cremasteric Muscle
Genital Branch of Genitofemoral Nerve (L1, L2)
Dartos Muscle
Smooth Muscle of Fat-Free Subcutaneous Tissue of Scrotum
Cremasteric Muscle
Draws Testis Superiorly in Scrotum in response to Cold
(Regulate Optimum Temperature for Spermatogenesis)
(1°C Below Core Body Temperature)
Acts Coincidentally with Dartos Muscle
Contents of Spermatic Cord
Ductus Deferens
Testicular Artery (from Abdominal Aorta)
Artery of Ductus Deferens (from Inferior Vesical Artery)
Cremasteric Artery (from Inferior Epigastric Artery)
Pampiniform Venous Ple xus (network formed by ≈ 12 veins that converge
superiorly as Right, Left Testicular Veins)
Sympathetic Nerve Fibers on Arteries
Sympathetic, Parasympathetic Nerve Fibers on Ductus Deferens
Genital Branch of Genitofemoral Nerve
Lymphatic Vessels
Vestige of Processus Vaginalis
Inguinal Triangle (Hesselbach) Triangle (Medial Inguinal Fossa)
Boundaries
Superolateral Medial Inferior
Inferior Epigastric
Artery
Rectus Abdominis
Muscle
Inguinal Ligament
Posterior Aspect of Anterolateral Abdominal Wall (Male)
Dermatome
Inguinal Region – L1
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Effects of ↑ Intra-Abdominal Pressure
Path of Inguinal Canal is Oblique
(Deep, Superficial Inguinal Rings in Adults Do Not Overlap – when Anterior,
Posterior Walls are Forced together by ↑ Intra-Abdominal Pressure)
IO, TA Contraction EO Contraction
Causes Roof of Canal to Descend Causes Superficial Ring to Constrict
Herniation
Congenital Abnormality
Acquired Weakness of Posterior Wall
of Inguinal Canal ↘ ↙
When Intra-Abdominal Pressure ↑ more than
Resistant Effect of ↓ Likelihood of HerniaFon Mechanisms ↓
Herniation
Indirect Inguinal Hernia
Congenital
Most common form of all Abdominal Hernias
Men ↑ (20X)
Lateral to Inferior Epigastric Vessels
Enters Deep Inguinal Ring
Has Hernial Sac Formed by
• Persistent Processus Vaginalis
• 3 Fascial Coverings of Spermatic Cord
Transverses Entire Inguinal Canal
Exits through Superficial Ring
Commonly Enters Scrotum
Reduces Upwards, then Laterally, Backwards
Controlled, after Reduction, by Pressure over the Internal Ring
Cysts, Hernias of Canal of Nuck (in Females)
Canal of Nuck
• Small Peritoneal Pouch in Inguinal Canal
(due to persistence of Proce ssus Vaginalis in Female)
(Usually Processus Vaginalis Degenerates)
• May Extend to Labium Majus
• Can Enlarge, Form Cysts in Inguinal Canal
• Have Potential to Develop into Indirect Inguinal Hernia
Direct, Indirect Inguinal Hernia
Direct Inguinal Hernia
Acquired
Leaves Abdominal Cavity Medial to Inferior Epigastric Vessels
Protrudes through an Area of Relative Weakness in Posterior Abdominal Wall
of Inguinal Canal
Has Hernial Sac Formed by Transversalis Fascia
Lies
• Outside Processus Vaginalis (Usually Obliterated)
• Parallel to Spermatic Cord
• Outside the Inner 1 or 2 Fascial Coverings of Cord
Does not Transverse Entire Inguinal Canal
(Usually only its most Medial part (lower end) adjacent to Superficial Ring)
Protrudes through Inguinal (Hesselbach) Triangle (Medial Inguinal Fossa)
Emerges through or around Conjoint Tendon to reach Superficial Ring
(Gaining an Outer Covering of External Spermatic Fascia, Inside or Parallel to
that on the cord itself)
Almost Never enter Scrotum
(However, when it does, It passes Lateral to Spermatic Cord,
Deep to Skin, Dartos Fascia)
Reduces Upwards, then Straight Backwards
Not Controlled, after Reduction, by Pressure over Internal Ring
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Scrotum
Continuous Sac
2 Layers
• Skin
• Dartos Fascia
o Fat Free Fascial Layer
o Smooth Muscle Fibers
Dartos Fascia is Continuous
Anteriorly Posteriorly
Membranous Layer of Subcutaneous
Tissue of Abdomen (Scarpa Fascia)
Membranous Layer of Subcutaneous
Tissue of Perineum (Colles Fascia)
Septum Scrotal Raphe
Divide Scrotum into Left, Right
Compartments
Cutaneous Ridge Marking the Line of
Fusion of Embryonic Labioscrotal
Swellings
Development of Scrotum
Develops from Labioscrotal Swellings
(2 Cutaneous Outpouchings of Anterior Abdominal Wall that fuse to form a
Pendulous Cutaneous Pouch)
Contraction of Dartos Muscles (Reduce Heat Loss)
Wrinkle the Scrotum
Thicken Integumentary Layer
↓ Scrotal Surface
Assists Cremaster Muscle to Hold the Testes closer to Body
Blood Supply
Posterior Scrotal
Branches of Perineal
Artery
Anterior Scrotal
Branches of Deep
External Pudendal
Artery
Cremasteric Artery
From Internal Pudendal
Artery
From Femoral Artery From Inferior Epigastric
Artery
Scrotal Veins accompany the Arteries
Lymphatic Vessels drain into Superficial Inguinal Lymph Nodes
Innervation
Nerve Area/ Surface Supplied
Branches of Lumbar Plexus
Genital Branch of Genitofemoral Nerve (L1, L2) Anterior
Anterior Scrotal Nerves
(Branches of Ilioinguinal Nerve) (L1)
Anterolateral
Branches of Sacral Plexus
Posterior Scrotal Nerves
(Branches of Perineal Branch of Pudendal
Nerve) (S2, S3, S4)
Posterior
Perineal Branch of Posterior Femoral Cutaneous
Nerve (S2, S3)
Inferior
Anaesthetizing Scrotum
Anterior 1/3rd
of Scrotum Posterior 2/3rd
of Scrotum
Supplied by L1 Supplied by S3
If Performing Spinal Anaesthetic Agent, Must be Injected at Right Spinal Level
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Testis (Capsule Made up by) (Superficial → Deep)
Tunica Vaginalis
(Distal Saccular Part of Processus Vaginalis forms Tunica Vaginalis)
• Parietal, Visceral layers
• Potential Space in between
(Cavity of Tunica Vaginalis – Site of Hydrocoele)
Filled with Thin Layer of Fluid
Parietal Layer Visceral Layer
Extends Superiorly into Distal Part
of Spermatic Cord
Closely Adherent to Testis,
Epididymis, Inferior Part of Ductus
Deferens
Covers all aspects of Testis
(Except most of Posterior Aspect,
where it attached to Epididymis,
Spermatic Cord)
Tunica Albuginea Thick, Dense Connective Tissue
Tunica Vasculosa Loose Connective Tissue
Blood Vessels
Sinus of Epididymis
Slit-like recess of Tunica Vaginalis
Between Body of Epididymis, Posterolateral Surface of Testis
Blood Supply
Testicular Arteries
• From Abdominal Aorta
• Anastomoses with Artery of Ductus Deferens
Pampiniform Venous Plexus
• Network of 8-12 veins
• Lies Anterior to Ductus Deferens
• Surrounds Testicular Artery in Spermatic Cord
• Veins Converge Superiorly – Forming Right Testicular Vein (Enters IVC) or
Left Testicular Vein (Enters Left Renal Vein)
• Forms part of Thermoregulatory System of Testis
Lymphatic Drainage
Follows Testicular Artery, Vein to
Right, Left Lumbar (Caval/ Aortic), Preaortic Lymph Nodes
Cremasteric Reflex
Lightly Stroking Skin on Medial Aspect of Superior Part of Thigh ↓
Contraction of Cremaster Muscle ↓
Rapid Elevation of Testis on Same Side
Ilioinguinal Nerve
Supply Medial Aspect of Superior Part of Thigh
This Reflex is Extremely Active in Children
Hydrocoele
Congenital Anomaly
Presence of Excess Fluid in a Persistent Processus Vaginalis
May be Associated with Indirect Inguinal Hernia
Fluid Accumulation is from Secretion of Abnormal Amount of Serous Fluid
(From Visceral Layer of Tunica Vaginalis)
Size is dependent on how much of Processus Vaginalis Persists
Newborn Male Infants Adults
Have Residual Peritoneal Fluid in
Tunica Vaginalis
Injury, Inflammation
Usually Absorbed during
1st
year of life
Physical Examination
Transillumination Test +ve
Hydrocoele of Testis Hydrocoele of Cord
Confined to Scrotum Confined to Spermatic Cord
Distends the Tunica Vaginalis Distends the Persistent Part of Stalk
of Processus Vaginalis
May Communicate with
Peritoneal Cavity
May Communicate with
Peritoneal Cavity
Haematocoele of Testis
Collection of Blood in Tunica Vaginalis
Due to Trauma
(Rupture of Branches of Testicular Artery)
Trauma may produce a Scrotal, Testicular Haematoma
(Accumulation of Blood, Usually Clotted, in any Extravascular Location)
May be Associated with Scrotal Haematocoele
Transillumination Test –ve (Differentiate from Hydrocoele)
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Torsion of Spermatic Cord
Common during Adolescence (May Occur at Any Age)
Usually Above Superior Pole of Testis
Surgical Emergency
High Scrotal Incision is Made (to Reduce Torsion)
To Prevent Recurrence (or Occurrence on Contralateral Side)(which is likely)
Both Testes are Surgically Fixed to Scrotal Septum
Spermatocoele, Epididymal Cyst
Spermatocoele Epididymal Cyst
Retention Cyst (collection of fluid) in
Epididymis (usually near its Head)
Collection of Fluid anywhere in
Epididymis
Contains a Milky Fluid
Asymptomatic
Vestigial Remnants of Embryonic Genital Ducts
Appendix of Testis Appendix of Epididymis
Vesicular Remnant of Cranial End of
Paramesonephric Duct
(Embryonic Genital Duct that in
Female Forms Half of Uterus)
Remnant of Cranial End of
Mesonephric Duct
(Embryonial Genital Duct that in Male
Forms Part of Ductus Deferens)
Attached to Superior Pole of Testis Attached to Head of Epididymis
Mesonephric Duct together with
Mesonephric Tubules associated with
it Normally forms Efferent Ductules,
Epididymis
Varicocoele
Kidney, Renal Vein Problems Defective Valves in Testicular Vein ↘ ↙
Affects Venous Drainage from Testicular Vein
(Obstruction, Reversal of Flow) ↓
Pampiniform Plexus become Dilated
(Varicose) Tortous ↓
Varicocoele
Left Side (Occurs Predominantly – 99%)
(due to nearly 90° at which Left Testicular Vein enters Left Renal Vein)
Usually Visible (when Man is Standing, Straining)
Disappears (when Lying Supine)(Scrotum is Elevated)
(Allowing Gravity to Empty the Vein)
Palpation
Feeling a Bag of Worms
Due to Left Predominance, Patient with
• Sudden onset of Varicocoele
• Right-Sided Varicocoele
• Varicocoele that Does Not Reduce in Size in Supine Position
Should be suspected of having Retroperitoneal Neoplasm
(in Testicular Vein Region)
Cancer of Testis, Scrotum
Lymphatic Drainage of Testes differ from Scrotum
Testicular Cancer
• Lymphogenous Metastasis is common
• Haematogenous Spread may also occur (Lungs, Liver, Brain, Bone)
Cancer 1st
Site of Metastasize Subsequent Spread
Testis Lumbar l/n
(lie just Inferior to Renal Veins)
Mediastinal, Supraclavicular
l/n
Scrotum Superficial Inguinal l/n
(lie in subcutaneous tissue,
inferior to inguinal ligament,
along terminal part of great
saphenous vein)
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