Anterior Abd. Wall Flashcards
Abdominal cavity boundaries (superior/inferior)
Superior = diaphragm Inferior = Pelvic inlet
Quadrants of abdominal cavities and what separates them
4 quadrants (R/L upper quadrant, R/L lower quadrant) separated by median plane and transumbilical plane
Region breakdown of abdominal cavity and what separates them
Going across:
- Rt hypochondrium - epigastric region - lft hypochondrium
- Rt. flank - umbilical region - left flank
- Rt. groin - pelvic region - left groin
separated by midclavicular planes, subcostal plane and intertubercular plane
Name the 9 layers from superficial to deep on abdominal cavity antero-laterally
- Skin
- Camper’s fascia (fatty subcutaneous)
- Scarpa’s fascia (deep membraneous)
- External oblique muscle
- Internal oblique muscle
- Transversus abdominins muscle
- Transversalias Fascia
- Extraperitoneal fat
- Parietal Peritoneum
*there is INVESTING FASCIA surrounding all of the muscular layers (investing = surrounding)
External Oblique Muscle
Lateral sides of abdomen, fibers go from high lateral to low anterior (fingers in pocket)
Has aponeurosis connecting two lateral sides
Linea Alba
Midline of aponeuroses of external oblique, internal oblique, and transversus abdominins.
Part of anchoring for all three of these layers.
Aponeurosis definition
tendinous sheet connecting two opposing muscles
Rectus Abdominins
Covered by aponeurosis of external oblique, paired, central muscles.
Has dense connective tissue anterior and posteriorly - these tissues coming together is called RECTUS SHEATH
Rectus Sheath
The connective tissues of the rectus abdominins (posteriorly and anteriorly) together is the rectus sheath. Changes superiorly to inferiorly at ARCUATE LINE.
Internal Oblique Muscle - fibers
Deep to external oblique muscle
Fibers directed opposite than external
Thumbs “up” in pocket to horizontal but hard to tell where the fibers change because they become interdigitated
Transversus Abdominins Muscle - fibers
Fibers are horizontal (transverse)
Arcuate Line
~midpoint between umbilicus and pubic symphysis, can only be seen posteriorly
denotes when rectus sheath structure changes (different superiorly and inferiorly)
Rectus sheath superior arcuate line
@ or above the umbilicus
Anterior: External oblique, 1/2 internal oblique
Posterior: 1/2 internal oblique, transversus abdominins, transversalias fascia and parietal peritoneum
Rectus sheath inferior to arcuate line
Closer to pubic symphysis
Anterior: external oblique, internal oblique, transversus abdominins
Posterior: transversalias fascia, parietal peritoneum
Which half of the rectus sheath is more translucent? Why?
Rectus sheath inferior to arcuate line
Because the posterior aspect of the rectus sheath only consists of transversalius fascia/parietal peritoneum which is thin therefore it becomes transclucent
Mesentery vs. Fold definition
Mesentery = 2 layers of mesothelium together
Fold = single layer of mesothelium
Name the 3 infraumbilical folds on the peritoneal
- Median Umbilical Fold (1)
- Medial Umbilical Folds (2)
- Lateral Umbilical Folds (2)
Median Umbilical Fold details
Only 1 - at midline
- From urinary bladder to umbilicals
- Covers median umbilical ligament (aka fibrous ligament also called remnant of the urachus)*
*results from embryonic atlantois that in late fetal is called urachus
IN ADULTHOOD ONLY CALL THIS THE REMNANT OF THE URACHUS OR THE UMBILICAL LIGAMENT
Medial Umbilical Folds details
R / L on either side of median umbilical fold
Covers medial umbilical ligament (occluded portion of umbilical artery)
Lateral Umbilical Folds
R / L on either side of medial umbilical folds
Covers inferior epigastric vessel (active!!! as opposed to remnants of other fold coverings)
What 2 structures can be seen in relation to the median/medial/lateral umbilical folds? Where are they found?
Deep Inguinal Ring: found just superior to lateral umbilical folds
Hesselbach’s triangle: found just superior to medial umbilical folds
Abdominal Wall Vasculature Summary (6)
- Superficial epigastric a. & v.
- Superficial circumflex a. & v.
- Deep circumflex iliac a. & v.
- Deep Inferior epigastric a. & v.
- Deep Superior epigastric a. & v.
- Deep Musculophrenic a. & v.
Superficial Circumflex Iliac a. & v. (branching and supply)
SUPERFICIAL VESSELS
- branch of femoral artery
- supplies/drains region of inguinal ligament
Superficial Epigastric a. & v. (branching and supply)
SUPERFICIAL VESSELS
- branch of femoral artery
- supplies/drains abdomen inferior to umbilicus
Deep Circumflex a. & v. (branching, supply, location)
DEEP VESSEL
- branch of external iliac
- runs between internal oblique and transversus abdominins
- Supplies inferior lateral abdominal musculature
Inferior Epigastric a. & v. (branching, supply, location)
DEEP VESSEL
- branch of external iliac
- enters posterior rectus sheath @ arcuate line
- supplies lower rectus abdominus musculature
- anastomose with superior epigastric a. & v.
Superior Epigastric a. & v. (branching, supply, location)
DEEP VESSEL
- branch of internal thoracic (mammary)
- enters posterior rectus sheath lateral to sternum (on either side)
- supplies upper rectus abdominus musculature
Musculophrenic a. & v. (branching, supply, location)
DEEP VESSEL
- branch of internal thoracic (mammary)
- runs along costal cartilage
- Supplies upper abdominal musculature
phrenic = diaphragm
Dermatome vs. Myotome innervation locations
Myotomes: innervate deeper muscles
Dermatomes: innervate cutaneous sections IN PATTERNS
Is the abdominal wall innervated by dermatomes or myotomes?
Dermatomes - because abdominal wall is CUTANEOUS. Follow PATTERN.
Define the innervation of the abdominal wall
Ventral Rami of T7-L1
T7, T8, T9 = supply region above umbillicus
T10 = supplies umbillicus region
T11, T12, L1 = supplies region below umbillicus
Ventral Rami T7-L1 innervate cutaneous surface. How do they get there?
T7, T8, T9, T10, T11, T12, L1 all run between internal oblique muscle and transversus abdominins muscle as they come up to innervate cutaneous surface
Injury to T7, T8, T9 results in _____
weakening to 1/2 of musculature. Makes this region weak but still functional
Injury to T11, T12, L1 result in ____
total weakening of inguinal region
Weakened sensation in region 3 inches below umbilcus is a result of ____
innervation problems with T12
Inguinal region:
Location in reference to abdominal region, thigh, ilum, pubic bone?
Inguinal region is
- inferior lateral to abdominal region
- Superior to thigh
- Medial to ilium
- Lateral to pubic bone
Inguinal region extends between _____ and _____.
Inguinal region extends between anterior superior iliac spine and pubic tubercle
What does the inguinal region contain?
Inguinal ligament, inguinal canal, superficial and deep rings, walls of canal
Vessels change name when passing through inguinal ligament. What’s the name before/after passing?
External iliac artery/vein becomes femoral artery/vein when passing through inguinal ligament
Inguinal Ligament definition
folded inferior border of external oblique aponeurosis (ie this is superficial)
extends from ASIS to pubic tubercle
Inguinal Canal definition
- Runs parallel to inguinal ligament
- Obliquely set tunnel 3-5cm long
- Transverses anterior abdominal wall (think: rungs traverse from inside abdominal cavity
MALE inguinal canal
Contains Spermatic cord and Ilioinguinal Nerve (@ L1)
Spermatic cord contains Vas Deferens, Testicular nn and vessels, Cremasteric muscle and fascia
Deep ring: opening to abdominal/pelvic cavity goes through structure and out superficial ring
FEMALE inguinal ring
Contains round ligament of uterus and Ilioinguinal Nerve (@L1)
Are spermatic cord and round ligament of uterus similar?
Spermatic cord and round ligament of uterus are derived from same embryological structure.
Both are contained in male/female inguinal canals respectively
Superficial Inguinal Ring
Opening in External Oblique Aponeurosis
Obvious triangular opening just LATERAL to pubic tubercle
Deep Inguinal Ring
Opening in Transversalias Fascia
Subtle piercing just lateral to inferior epigastric.
(think: deep inguinal ring found just lateral to umbilical folds which cover inferior epigastric)
What compose the anterior/posterior walls of the inguinal canals? What compose the roof/floor of inguinal canals?
Anterior wall: EO aponeurosis
Posterior wall: transversalias fascia, conjoint tendon
Roof: Internal oblique and transversus abdominus m (superior)
Floor: inguinal ligament (inferior)
Conjoint tendon defintion
Fusion of Internal Oblique, Transversus Abdominus aponeuroses medially.
Part of the posterior wall of the inguinal canal
Hernia definition
Hernia is an outpocketing of viscera within a sac
Abdominal hernia definition
Out-pocketing of abdominal viscera within a sac.
What is a hernial sac composed of?
Hernial sac composed of 3 layers
- Peritoneum, extraperitoneal fat, transversalias fascia
Are hernias common in inguinal region?
90% of hernias occur in inguinal region because we have a CANAL here
Indirect Inguinal Hernia definition
Most common type of hernia (male>female)
- extends thru entire inguinal canal
- lateral to inferior epigastric vessel (bc exits thru deep ring which is lateral to lateral umbilical fold which contains inferior epigastric vessel)
Indirect inguinal hernia commonly enters the ____ in male, and the ___ in females.
Indirect inguinal hernia commonly enters the scrotum in male, and the labia majora in females.
In males, indirect inguinal hernia is usually caused by _______.
In males, indirect inguinal hernias are usually caused b persistent processus of vaginalus (which connects peritoneum with descended testes)
In females, we can refer to indirect inguinal hernias as _____.
In females, we can refer to indirect inguinal hernias as CANAL OF NUCK.
Direct Inguinal Hernia definition
extends through inguinal triangle (Hesselbach’s triangle)
emerges through conjoint tendon by or at the superficial ring
doesn’t enter scrotum/labia majoria because so medial and superficial
associated with weakened abdominal wall (beer belly)
Where is hesselbach’s triangle?
Hesselbach’s triangle/inguinal triangel=
between inferior epigastric aa., rectus abdominus m., inguinal ligament
AKA THIS IS MEDIAL TO INFERIOR EPIGASTRIC (think back in relation to medial umbilical folds)
Femoral Hernia
-Through femoral ring and canal
= medial compartment of sheath
-More common in male than female because males have wider femoral ring
Umbilical Hernia
Through umbilical ring
most common in newborns/obese individuals
more common in male
Epigastric Hernia
through linea alba
most common in over 40 and severe obesity
Pathway for accessory pancreatic duct
May enter duodenum as well
~2cm above major papilla at the minor duodenal papilla
Ascites
fluid (from peritoneum during herniation)
What are the branches of the celiac trunk?
- Common hepatic (right branch)
- Left gastric (superior branch)
- Splenic branch (left branch)
what does the celiac trunk solly?
FOREGUT: Liver, gallbladder, esophagus, stomach, pancreas, spleen
What does the common hepatic branch supply?
Liver and gall bladder
What are the terminal branches of the common hepatic bramch?
- Proper hepatic artery (superior)
2. Gastroduodenal artery (inferior)
What does the proper hepatic supply?
Runs towards liver and medial to bile duct
Proper hepatic terminal branches?
- Right gastric artery
2. Proper hepatic bifurcates into right and left hepatic arteries
Gastroduodenal artery terminal branches?
- Superior anterior pancreaticoduodenal artery
- Superior posterior pancreaticoduodenal artery
- Right gastroepiploic (right gastro-omental)
Superior anterior/posterior pancreaticoduodenals arteries supplies what?
Pancreas and duodenum
*after anastomes with inferior anterior/posterior pancreaticoduodenal arteries
what does the left gastric artery supply?
runs towards lesser curvature supplies stomach and esophagus
What does the splenic artery supply?
pancreas and spleen
