ABDOMEN I:
ANTEROLATERAL ABDOMINAL WALL Abdomen boundaries: Superiorly: • Diaphragm (T10 roof) • Xiphoid • Costal cartilages Sides/walls: • Musculotendinous (flank mm.) • Lumbar vertebral bodies & trans. processes • False ribs (11-12) Inferior • False pelvis • Superior pelvic opening (pelvic brim)
Note: • Angle of abdominopelvic cavity • changes @ sup. pelvic opening • One continuous cavity: abdominal organs can become pelvic and vice versa (bladder, intestine) HIP BONES (2) [os coxae, coxal bones] Iliac Crest
Arcuate line Anterior Superior of the ilium Iliac Spine (ASIS) ILIUM
Pectineal line (pectin pubis) Auricular surface Pubic tubercle (for S-I jnt.) PUBIS ISCHIUM
Pubic crest
Pubic symphysis -classic fibrocartilaginous jnt. MIDCLAVICULAR PLANES (R&L)
Lateral border of rectus m. intersects costal cartilage
RIGHT EPIGASTRIC LEFT HYPOCHONDRIAC EPIGASTRIC HYPOCHONDRIAC TRANSPYLORIC PLANE
RIGHT UMBILICAL LEFT UPPER UPPER LUMBAR LUMBAR RIGHT LEFT
INTERTUBERCULAR PLANE LOWER LOWER RIGHT HYPOGASTRIC LEFT INGUINAL INGUINAL RIGHT LEFT SUPERFICIAL FASCIA OF THE ABDOMINAL WALL
Fascia lata (deep fascia of thigh) Camper’s fascia -fatty layer
Scarpa’s fascia -membranous layer -visible on CT -can hold suture Position of Penis Colles’ fascia Position of Scrotum -membranous layer Camper’s fascia Scarpa’s fascia
Superficial Penile (Clitoral♀) Fascia
Colles’ fascia
Dartos fascia -male only -smooth muscle mixed in -gives scrotum a “raisin skin” appearance ABDOMINAL WALL VEINS
lateral thoracic vein portal vein in drains to axillary vein porta hepatis
lumbar veins paraumbilical veins (follow falciform ligament in liver and extend onto anterior abdominal wall)
superficial epigastric vein drains to great saphenous vein (then femoral)
ABDOMINAL WALL ARTERIES/NERVES
supplies rectus abdominus m.
supplies lateral wall (flank) muscles Intercostal/Subcostal/L1 nerves: Supply segmental motor and sensory innervation to abdominal wall
Subcostal Nerve
Superficial Inguinal Ring supplies rectus abdominus m. sensation to thru inguinal canal mons pubis/upper groin sensation to ext. genitalia LYMPH DRAINAGE ON ANTEROLATERAL ABDOMINAL WALL
Axillary Lymph Nodes
T10 (umbillicus) level is “watershed” line
Superficial Inguinal y Lymph Nodes anterior sacroiliac lig. -nearly motionless
pectineal lig. (a.k.a. Cooper’s lig.) -thickening of periosteum -can suture to it (strong)
inguinal lig. lacunar lig. (ASIS→pub. tubercle) (inguinal lig.→pectineal lig.) EXTERNAL OBLIQUE
• Outermost flank mm. • Lateral & posterior = muscular Inguinal • Anterior & inferior = tendinous Ligament • Fibers project inferomedially • Originates from ribs 5-12 • Inserts on: • Antimere in midline (linea alba) • Pubic symphysis (superior edge) • Pubic tubercle • NOT along pubic crest • Iliac crest
Pubic Superficial Inguinal Ring Tubercle INTERNAL OBLIQUE
• middle flank mm. Thoracolumbar • Lateral = muscular Fascia • Anterior = tendinous • Fibers project superomedially • Originates from: Inguinal • thoracolumbar fascia Ligament • Iliac crest • Inguinal lig. • Inserts on: • Antimere in midline (linea alba) • Lower ribs & costal cart. • Pubic symphysis (superior edge) • Pubic crest & beginning of pectineal line
Internal Oblique contribution to the CONJOINT TENDON -fusion of internal obl. and transversus abd. aponeuroses along pubic crest & portion of pectineal line TRANSVERSUS ABDOMINUS
Thoracolumbar Fascia Inguinal Ligament Arcuate Line of the • innermost flank mm. Abdominal • Lateral = muscular Wall • Anterior = tendinous • Fibers project transversely • Originates from: -a slit in the • Thoracolumbar fascia aponeurosis • Iliac crest that allows rectus • Inguinal lig. abd. to pass • Costal cartilages • Inserts on: • Antimere in midline (linea alba) • Pubic symphysis (superior edge) • Pubic crest & beginning of pectineal line
Transversus Abdominus contribution to the CONJOINT TENDON RECTUS ABDOMINUS
position of gall bladder (transpyloric plane) tendinous insertions
Linea semilunaris
• “strap” mm. • Tendinous insertions =multiple muscle bellies Linea Alba • Fibers project -fusion raphe btwn. superoinferiorly R & L aponeuroses • Originates from: from flank mm. • Costal cart. of ribs 5-8 McBurney’s point: • Sternum/xiphoid rds • Inserts on: (2/3 distance from • Pubic crest umbillicus to ASIS) • Pubic symphysis -approx. position of (superior edge) appendix linea alba
McBurney’s linea Point semilunaris =appendix
Function of abdominal wall muscles (flank mm. and rectus):
•Stabilize the trunk •Flexion •Lateral flexion •Torsion •Abdominal compression (working with diaphragm) ORGANIZATION OF RECTUS SHEATH
External Oblique
Internal Oblique
Transversus Abdominus rectus sheath Rectus Abdominus Tendinous covering around rectus muscles, derived from flank mm. aponeuroses
Arcuate Line of Abdominal Wall ABOVE RECTUS ARCUATE LINE
BELOW ARCUATE RECTUS LINE
Transversalis fascia Peritoneum DEEP SURFACE OF ANTERIOR WALL
Median fold (1) houses median umbilical ligament (urachus remnant) Falciform lig. Medial folds (2) • Separates liver into R & L house obliterated anatomical lobes umbilical arteries • Bottom free edge houses paraumbilical veins and round lig. of the liver Lateral folds (2) houses inferior epigastric vessels INGUINAL CANAL
intercrural fibers deep inguinal ring (prevents “banana-peeling”) -hole in transversalis fascia
inguinal canal lateral crus
medial crus
INGUINAL CANAL CONTENTS: •Ilioinguinal nerve superficial inguinal ring •Spermatic cord (♂) -hole in external obl. aponeurosis •Round ligament of the uterus (♀) testicular blood vessels
vas deferens
BLADDER
spermatic cord HESSELBACH’S TRIANGLE – SEEN FROM DEEP SURFACE OF ANDOMINAL WALL Borders: medial = rectus abdominus inferior = inguinal ligament lateral = inferior epigastric artery
Deep ring: always lateral to triangle superficial ring: overlaps triangle EPIDIDYMIS Efferent ductules Head Body Testicular a. Tail Pampiniform plexus
Sac made from peritoneum that covers the anterior, lateral, and inferior portions of the testis SPERMATIC CORD
Vas deferens External spermatic fascia Genital branch of genitofemoral nerve Cremasteric fascia (with cremaster muscle)
Internal spermatic fascia
Pampiniform plexus
Testicular a. SPERMATOCELES
• Caused by cysts in the rete testis, efferent ductules, and head of epididymis. • Cysts are distended with milky fluid that contains sperm. • Asymptomatic except when large, causing testicular discomfort. • Can be transilluminated (e.g., flashlight) • Causes: – Epididymitis (infection) – tubule diverticula that swell over time from spermatogenesis TESTICULAR VARICOCELES (BAG OF WORMS) • Reduced venous return from testes via pampiniform plexus. • Results in enlargement of the veins, looks and feels like a “bag of worms.” • More common on left side because of left testicular vein drainage. • Frequently occurs in runners neglecting proper support (bouncing). • Usually develops slowly; usually no symptoms. • Common cause of infertility in men.
TESTICULAR TORSION • Spermatic cord gets twisted around the blood vessels, cutting off testicle's blood supply, • Most common in 12-18 yr olds. • Usually caused by sports- related groin injury: cremaster spasms and twists testis. • Immediate pain. • Requires immediate treatment to save testis (untwist and suture to scrotal wall). HYDROCELES
NORMAL CONGENITAL FUNICULAR VAGINAL
Hydrocele: Accumulation of serous fluid around one or both testicles (within tunica vaginalis or processus vaginalis ) that causes the scrotum or groin area to swell. INDIRECT INGUINAL HERNIA
-enters thru deep ring (lateral to Hesselbach’s Δ)
-deep ring fails to seal off
-can proceed all the way thru inguinal canal to scrotum or labium majus INDIRECT HERNIA -enters wall lateral to inf epigastric a.
DIRECT HERNIA -medial to inf epigas. art
-failure of the conjoint tendon 2%