Anterior Abdominal Wall and Inguinal Canal
Layers of rectus sheath below arcuate line
1. External oblique - anterior to rectus abdominis 2. Internal oblique - anterior to rectus abdominis 3. Transversus abdominis - anterior to rectus abdominis 4. Transversalis fascia - posterior to rectus abdominis muscle 5. Peritoneum
Layers of rectus sheath above arcuate line
1. External oblique - tendon passes anterior to rectus abdominis muscle 2. Internal oblique - tendon divides to surround the rectus abdominis muscle 3. Transversus abdominis - passes posterior to the rectus abdominis muscle 4. Transversalis fascia 5. Peritoneum
Epididymis
A long, coiled duct on the outside of the testis in which sperm mature.
Which option most accurately describes the attachment sites of the inguinal ligament? ASIS to public symphysis PSIS to pubic tubercle ASIS to pubic tubercle PSIS to pubic symphysis
ASIS to pubic tubercle
external abdominal oblique muscles
Accessory muscles of expiration
lateral cutaneous branches
Has anterior and posterior branches; supplies the skin of the lateral thoracic and abdominal walls intercostal nerves iliohypogastric nerves
inguinal rings
Openings where the testicles pass through the abdominal wall, and the vas deferens and testicular vessels then continue to course medial crus superficial inguinal ring pubic tubercle lateral crus
contents of female inguinal canal
Round ligament of uterus and ilioinguinal nerve
layers of the abdominal wall
Skin Fat (camper's fascia) Scarpa's fascia (membranous) External oblique Internal oblique Transverse abdominal Transversalis fascia Preperitoneal fat Peritoneum
transversalis fascia
Structure that forms deep inguinal ring --> continuous with internal spermatic fascia
inguinal canal
a short canal passing through the abdominal wall in the region of the groin in males where testes descends into the scrotum
abdominal wall derivative of the scrotal skin
abdominal skin
transversus abdominis muscles
abdominal support and compression
Boundaries of Abdomen
abdominopelvic cavity four planes: two sagittal (vertical) and two transverse (horizontal)
anterior rectus sheath
all 3 muscle layer aponeurosis (external, internal, transversus) - posterior rectus sheath is absent below the arcuate line
borders of the inguinal canal
anterior --> aponeurosis of external oblique, reinforced by the internal oblique muscle laterally posterior --> transversalis fascia roof --> transversalis fascia, internal oblique, transversus abdominis floor --> inguinal ligament ('rolled up' portion of the external oblique aponeurosis), thickened medially by the lacunar ligament
inguinal region
anterior superior iliac spine inguinal ligament (passing anterior to the pecten pubis) pubic tubercle
medial third/superficial ring of the anterior wall of inguinal canal
aponeurosis of external oblique (intercrural fibers) fascia of external oblique continuing onto cord as external spermatic fascia
middle third of the anterior wall of inguinal canal
aponeurosis of external oblique (lateral crus and intercrural fibers)
unilateral action of external abdominal oblique muscles
bends trunk to same side rotates trunk to opposite side
unilateral action of internal abdominal oblique muscle
bends trunk to same side rotates trunk to same side
bilateral action of transversus abdominis muscles
compresses abdomen
origin of transversus abdominis muscles
costal cartilages of ribs 7 - 12 thoracolumbar fascia iliac crest anterior superior iliac spine (ASIS)
Deep (internal) ring
created by transversalis fascia which invaginates to form a covering of the contents of the inguinal canal found above the midpoint of the inguinal ligament lateral to epigastric vessels
abdominal wall derivative of the tunica dartos
dartos fascia and muscle
structure leaving scrotum
ductus deferens
lower region lymphatics
external and common iliac nodes superficial inguinal nodes
contents of male inguinal canal
external oblique --> external spermatic fascia internal oblique --> cremaster muscle transversalis fascia --> internal spermatic fascia testicular artery pampiniform plexus (testicular veins) testicular plexus ductus deferens
abdominal wall derivative of the external spermatic fascia
external oblique fascia
Muscles of the abdominal wall
external oblique, internal oblique, transversus abdominis, rectus abdominis
rectus sheath
fibrous sheath formed by aponeuroses of abdominal muscles continuous layer of connective tissue from the linea alba to the external oblique muscles splits into two layers at the linea alba to cover the abdominal muscles
rectus abdominis muscles
flexes and rotates vertebral column (abs)
action of rectus abdominis muscles
flexes trunk compresses abdomen stabilizes pelvis
bilateral action of external abdominal oblique muscles
flexes trunk compresses abdomen stabilizes pelvis
bilateral action of internal abdominal oblique muscle
flexes trunk compresses abdomen stabilizes pelvis
Valsalva maneuver
forcible exhalation against a closed glottis, resulting in increased intrathoracic pressure
Superficial (external) ring
formed by the evagination of the external oblique marks the end of the inguinal canal and lies superior to the pubic tubercle
anterior cutaneous branches
has medial and lateral branches; supplies the skin of the anterior thoracic and abdominal walls intercostal nerves iliohypogastric nerves
lateral third/deep ring of floor of inguinal canal
iliopubic tract
middle third/superficial ring of the posterior wall of inguinal canal
inguinal falx aka conjoint tendon reflected inguinal ligament
middle third of floor of inguinal canal
inguinal ligament
innervation of rectus abdominis muscles
intercostal nerves (T6 - T12)
innervation of transversus abdominis muscles
intercostal nerves (T6 - T12) iliohypogastric nerve ilioinguinal nerve
innervation of internal abdominal oblique muscle
intercostal nerves (T6 - T12) iliohypogastric nerve ilioinguinal nerve
innervation of external abdominal oblique muscles
intercostal nerves (T7-T12)
innervation to the abdominal wall
intercostal nerves, lateral cutaneous branches intercostal nerves, anterior cutaneous branches iliohypogastric nerve, lateral cutaneous branch iliohypogastric nerves, anterior cutaneous branch
lateral third/deep ring of the anterior wall of inguinal canal
internal oblique lateral crus of aponeurosis of external oblique
abdominal wall derivative of the cremaster muscle and fascia
internal oblique muscle and fascia
Veins of abdominal wall
internal thoracic vein (superficial, superior) axillary vein lateral thoracic vein (superficial, superior) thoracoepigastric vein (deep) peri-umbilical veins (deep) superficial epigastric vein (superficial, inferior) inferior epigastric vein (superficial, inferior)
medial third/superficial ring of floor of inguinal canal
lacunar ligament
what creates the passage to the inguinal canal?
lacunar ligament --> connects with deep inguinal ring
upper region lymphatics
left and right venous angles axillary and parasternal nodes
lymphatics of abdominal wall
like other superficial regions of the body, the lymph from the abdominal wall has both superficial & deep channels of drainage lymph from skin & superficial fascia from the anterior abdominal wall above the umbilicus drains mainly to axillary nodes. lymph from below the umbilicus drains to superficial inguinal nodes lymph from deeper aspects of the body wall (muscles) terminates in internal & common iliac nodes; these then drain to lateral aortic nodes
insertion of transversus abdominis muscles
linea alba pubic crest
insertion of external abdominal oblique muscles
linea alba pubic tubercle anterior half of the iliac crest
middle third/superficial ring of roof of inguinal canal
medial crus of aponeurosis of external oblique
middle third of roof of inguinal canal
musculophrenic arches of internal oblique and transverse abdominal
external view of the epididymis
parietal layer of tunica vaginalis visceral layer of tunica vaginalis
Direct inguinal hernia
peritoneal sac enters the inguinal canal through the posterior wall of the inguinal canal to the epigastric vessels (medial) and can enter the superficial inguinal ring acquired due to weakening in the abdominal musculature
abdominal wall derivative of the tunica vaginalis
peritoneum
why are the regions of the abdominal wall important?
planes can be used to establish nine regions (more detailed) or four quadrants (more general) important to know what organs are located in each abdominal region/quadrant so that one knows where to auscultate, percuss, and palpate them and record locations of findings during a physical examination
An indirect inguinal hernia can result from the failure of the ____ to regress.
processus vaginalis
origin of rectus abdominis muscles
pubic symphysis pubic crest
insertion of internal abdominal oblique muscle
ribs 10 - 12 linea alba
origin of external abdominal oblique muscles
ribs 5 - 12
unilateral action of transversus abdominis muscles
rotates trunk to the same side
internal abdominal oblique muscle
runs in a posteroinferior direction splits to contribute to the rectus sheath contributes to the formation of the conjoint tendon in men gives rise to the middle spermatic fascia and the cremasteric muscle of the spermatic cord
scrotum
sac-like continuation of the skin of the anterior abdominal wall
covering of the testis
scrotal skin tunica dartos external spermatic fascia cremaster muscle and cremasteric fascia internal spermatic fascia tunica vaginalis, parietal layer tunica vaginalis, viserval layer
posterior rectus sheath
seen when rectus abdominis is removed underneath the aponeurosis
structure entering scrotum
spermatic cord
internal view of epididymis
spermatic cord visceral layer of tunica vaginalis tunica albuginea
arterial supply to anterior abdominal wall
superior epigastric artery inferior epigastric artery (IEA) superficial epigastric artery superficial circumflex iliac artery
general functions of abdominal muscles
support and protect viscera flex and rotate vertebral column forced expiration flatten anterior abdominal wall help lift lower limb valsalva maneuver
surface features of the abdomen
tendinous intersections linea semilunaris linea alba umbilicus pubic symphysis inguinal ligament anterior superior iliac spine
origin of internal abdominal oblique muscle
thoracolumbar fascia anterior 2/3 of iliac crest
Which of the following forms the posterior wall of the inguinal canal? internal oblique inguinal ligament aponeurosis of external oblique transversalis fascia
transversalis fascia
abdominal wall derivative of the internal spermatic fascia
transversalis fascia
lateral third/deep ring of roof of inguinal canal
transversalis fascia
lateral third/deep ring of the posterior wall of inguinal canal
transversalis fascia
middle third of the posterior wall of inguinal canal
transversalis fascia
Indirect inguinal hernia
where peritoneal sac enters the inguinal canal through the deep inguinal ring --> may transverse the entire inguinal canal, emerge through the superficial inguinal ring, and reach the scrotum. This condition usually is due to a congenital defect in the abdominal wall.
tunica albuginea
white fibrous capsule on testes - innermost layer
insertion of rectus abdominis muscles
xiphoid process 5th - 7th costal cartilages