Editing Inguinal region (section)

== '''Inguinal canal:''' ==

* '''Relations'''
** Inguinal ligament      inferiorly, with medial contributions from lacunar ligament
** Conjoint tendon superiorly      (transversus abdominis and internal oblique - although it is disputed in      anatomical literature as to whether these fibres are actually fused),      which curves from in front of the cord laterally to behind the cord      medially, and then it inserts into the pubic crest and pectineal line of      the pubic bone
** Transversalis fascia      posteriorly, fused with iliopubic tract
** External oblique anteriorly
** '''Internal      ring''' laterally      - point of entry of spermatic cord structures into the inguinal canal
*** This is best conceptualised       as a '''defect in transversalis fascia''', with fibres from IO and       TA curving superiorly
*** Midway between ASIS and       pubic symphysis - mid-inguinal point
*** Inferior border       formed/reinforced by iliopubic tract (see above under TA)
*** Lateral border reinforced       by the interfoveolar ligament (Hesselbach's ligament) - see separate       topic above under 'structures'
*** External ring medially
*** Triangular opening in EO       aponeurosis, superior and 1.5cm laterally to the pubic tubercle
** Superficial ring medially
** '''Hesselbach's      triangle:''' 
*** The margins of the floor of       the inguinal canal
*** Inferior epigastric       vessels, rectus sheath, inguinal/pectineal ligament
*** Direct hernias occur       through this triangle
* '''Strength'''
** Laterally: EO aponeurosis
** Medially: conjoint tendon
* '''Contents''' (spermatic cord/round     ligament, genital branch of genitofemoral nerve, and ilioinguinal nerve)
** Men:
*** '''Spermatic       cord''' - (3       arteries, 3 fasciae, 3 nerves, 3 other things)
**** '''3        arteries'''        (testicular, deferential, cremasteric)
***** Testicular - largest         artery in the cord. Originates from aorta. Gives off a branch to the         epididymis, then divides to medial and lateral branches at the back of         the testis. There is an anastomosis between testicular, cremasteric         and ductal arteries in the region of the epididymis, but atrophy will         probably still occur if the main testicular artery is divided (frank         necrosis is actually unlikely according to Last's).
***** Cremasteric artery:         originates from inferior epigastric at level of deep ring. Supplies         cremasteric muscle and coverings of the cord. Enter inguinal canal         through their own foramen in the posterior wall.
***** Artery to the vas or         'deferential artery' - from the superior or inferior vesical
**** '''3 fasciae''' (external, cremasteric,        internal spermatic fascia)
***** External spermatic fascia         - acquired from EO aponeurosis as the cord passes through the         superficial ring
***** Cremaster         muscle/cremasteric fascia - striated muscle bundles united by areolar         tissue. Arises laterally from the inguinal ligament, IO and TA         muscles. The longest fibres reach as far down as tunica vaginalis of         the testis, and loop back to attach to pubic tubercle. Functions to         reflexively elevate the testis towards the inguinal canal.
***** Internal spermatic fascia         is derived from transversalis fascia. It projects along the canal like         a sleeve, containing everything that passes through deep ring.
**** '''3 nerves''' (genital branch of        genitofemoral nerve, ilioinguinal, sympathetic)
***** Genital branch of         genitofemoral - see below.
***** Ilio-inguinal - see         below. Outside cord.
***** Sympathetic twigs         accompany the arteries
**** '''3 other''' (ductus deferens,        pampiniform plexus, lymphatics)
***** Ductus deferens - usually         lies in medial or posterior part of the cord. Direct continuation of         the canal of the epididymis. Leaves the canal via the deep ring,         passes medially just under the peritoneum, pierces the prostate and         opens into the prostatic urethra.
***** Pampiniform plexus - mass         of intercommunicating veins from testis, which surround the testicular         artery. Separates out into about four veins in the inguinal canal, and         becomes one on the surface of psoas. Left vein to left renal vein and         right vein directly to IVC.
****** ''Jamieson's says there are also cremasteric vein (to          IEV) and deferential veins (to IIV)''
***** Lymphatics - those from         the testis draining to para-aortic nodes, and those from the coverings         draining to external iliac nodes
**** '''Processus        vaginalis'''
***** When patent it forms the         sac of an indirect inguinal hernia
**** Arrangement (from external        to internal)
***** External fascia
****** Ilioinguinal          nerve
****** Lymphatics          from cord coverings
***** Cremasteric fascia
****** Cremasteric          artery and vein and nerve (genital branch of genitofemoral nerve)
***** Internal fascia
****** Testicle,          testicular artery, pampiniform plexus, lymphatics
****** Ductus          deferens and deferential artery/vein
****** Sympathetic          twigs

* Women:
** Obliterated processus      vaginalis
** Round ligament
** Lymphatics from uterus
* '''Nerves'''
** '''Iliohypogastric''' - Originates L1. Bifurcates      into lateral and anterior cutaneous branches above the iliac crest. First      pierces IO 3cm medial/superior to ASIS to travel between IO and EO. The      anterior cutaneous branch does not traverse internal ring, but enters on      superior border between transversis abdominis and internal oblique,      running 2cm superior to cord. Supplies skin of pubic region. Not usually      seen during IHR.
*** Lateral cutaneous branch       peels off above iliac crest, supplying posterolateral gluteal skin
** '''Ilioinguinal''' - Usually from L1. First      pierces IO 2cm medial/superior to ASIS to travel between IO and EO. Does      not traverse internal ring, enters on superior border between transversus      abdominis and internal oblique. Found anterior to the cord within the      inguinal canal. Exits the superficial ring along with the cord, and then      travels in between external and internal spermatic fascia. Sensory nerve      - base of penis, upper medial thigh.
** '''Genital      branch of genitofemoral''' - Originates L1 (femoral) and L2 (genital) and courses      inferiorly along psoas.
*** Genital branch enters canal       via the inferior aspect of the deep ring and lies posterior in the cord.       Supplies cremaster muscle and the skin of lateral scrotum/labia.
*** Femoral branch passes       through the femoral sheath beneath inguinal ligament, lateral to femoral       artery, and supplies skin of thigh over femoral triangle.
* Any indirect hernia would     reside anterior to these structures in the inguinal canal

* '''Structures     deep to the posterior wall:'''
** Inferior epigastric artery.      Gives off cremasteric branch at the deep ring.