gross anatomy inguino scrotal region

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



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)



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)



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



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



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



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)



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)



gross anatomy inguino scrotal region

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