Abdomen I: Abdominal Wall & Cavity Flashcards
What are the 4 boundaries of the Abdomen?
- Superior
- Posterior
- Anterolateral
- Inferior
Where is the Superior boundary?
The diaphragm
(fifth intercostal space)
Where is the Posterior boundary?
Lumbar vertebrae and quadratus lumborum muscles
Where is the Anterolateral boundary?
The muscles of abdominal wall
Where is the Inferior boundary?
The pelvic brim
What is the abdominal wall function?
- RETAIN (help hold everything in) and PROTECT Abdominal Organs
- Produce ANTERIOR & LATERAL FLEXION and help maintain POSTURE
- INCREASE intra-abdominal PRESSURE:
- forced expiration
- defecation
- urination
- vomiting
- childbirth
What are the 4 Quadrants of the Abdominal?
- Right upper quadrant (RUQ)
- Left upper quadrant (LUQ)
- Right lower quadrant (RLQ)
- Left lower quadrant (LLQ)
What are in all of the 4 quadrants?
intestines
- can travel through all if there’s a problem
What are the 9 abdominal regions?
- Right hypochondria region
- Epigastric region
- Left hypochondria region
- Right lumbar region
- Umbilical region
- Left lumbar region
- Right Iliac (inguinal) region
- Hypogastric (public) region
- Left iliac (inguinal) region
What are the 9 layers of the abdominal wall?
- Skin
- Superficial fascia - fatty layer (Camper’s fascia)
- Superficial fascia - membranous layer (Scarpa’s fascia)
- External oblique muscle
- Internal oblique muscle
- Transversus abdominis muscle
- Transversalis fascia
- Extraperitoneal fascia
- Parietal peritoneum
What are the functions of the Anterolateral Abdominal Wall?
- Retain & PROTECT abdominal
viscera - Maintain POSTURE via anterior & lateral flexion and rota)on of trunk
- Maintain & INCREASE INTRA- ABDOMINAL PRESSURE during respira)on, defeca)on, urina)on, vomi)ng, and child birth
What is the innervation of the Anterolateral Abdominal Wall muscles?
Thoracoabdominal nerves (T7-T11), subcostal (T12), and L1 nerves
Where is the External Oblique? & what is its actions?
- Outermost layer of abdominal muscles
- Fibres run DOWN AND TOWARDS THE MIDLINE “Hands in your pockets”
Actions: flexion and rota)on of the trunk, compression of viscera
Includes the External oblique aponeurosis - CT that extends from muscles (makes midline stronger - gives extra strength)
What is the Internal Oblique? & what is its actions?
- Middle layer of abdominal muscles
- Fibres run DOWN AND AWAY FROM THE MIDLINE – Int. perpendicular to externaloblique obliques
- Actions: flexion and rotation of the trunk, compression of viscera
Includes the Internal oblique aponeurosis
What is the Transversus Abdominis? What is its action?
- Deepest and thinnest layer of abdominal muscles
- Fibres run HORIZONTALLY
therefore - Actions: compression of viscera only! No trunk movement! “Suck it in”
Includes Transverse abdominis aponeurosis & Transversalis fascia (helps give structure to wall)
What is the Rectus Abdominis? What is its actions?
- Pair of long, straplike muscles that extend vertically from the pelvis to the ribs
- Separated by the LINEA ALBA (midline)
- Enclosed within the rectus sheath (aponeuroses of obliques)
- Muscle is separated into segments by TENDINOUS INTERSECTIONS (allow for: 8 pack)
- bands of CT
- Actions: Flexion of the trunk, compression of viscera
Includes: Linea Alba
What is an Abdominal Wall Hernia?
when abdominal wall is weak
What are the 4 types of hernias?
- Linea Alba Hernia
- Umbilical Hernia
- Spigelian Hernia
- Incisional Hernia (after surgery)
Which organs can pop out of a hernia?
intestines
What are the 4 muscles of the Anterolateral Abdominal Wall?
- External Oblique
- Internal Oblique
- Transversus Abdominis
- Rectus Abdominis
What are the 2 muscles of the Posterior Abdominal Wall?
- Quadratus Lumborum
- Psoas major
What is the Quadratus Lumborum?
- Square-shaped muscle originating on the pelvis
- Powers lateral flexion of the lumbar spine
- Stabilizes the 12TH RIB against the action of the diaphragm during inspiration
What is the Psoas major?
- Combines with iliacus to form iliopsoas
- Powers hip flexion and can also flex the trunk laterally
- Innervated by the femoral nerve (in ant. thigh)
What is the Vasculature of Anterior Abdominal Wall?
Subclavian Artery:
- Internal Thoracic artery
- Superior Epigastric artery
- Inferior Epigastric artery (Lies in the LATERAL UMBILICAL FOLD)
External Iliac Artery
Which arteries run posterior to the rectus abdominus?
Superior/inferior Epigastric arteries
What is the innervation of the abdominal wall?
Thoracoabdominal nerves (T7-T11)
Subcostal Nerve (T12)
L1 nerves:
- Iliohypogastric Nerve (L1)
- Ilioinguinal Nerve (L1)
What is the innervation of the Iliohypogastric Nerve (L1)?
Innervates Internal oblique & transversus abdominis muscles and skin of upper inguinal region.
What is the innervation of the Ilioinguinal Nerve (L1)?
- Innervates Internal oblique & transversus abdominis muscles.
- Innervates skin of scrotum, labia majora, and adjacent medial aspect of thigh.
What is the Inguinal Canal?
- 4 cm long tube-like space within the lower part of the anterior abdominal wall
- Begins at the DEEP INGUINAL RING and ends at the SUPERFICIAL INGUINAL RING
- Present in males AND females (but diff what runs through it)
- It is through here that the testes, which develop in the abdominal cavity, descend down into the scrotum
Where do we check for herniations in males mostly (b/c females have a smaller space)?
inguinal canal
What are the boundaries of the Inguinal Canal?
Anterior Wall –> EO aponeurosis
Posterior Wall –>Mostly transversalis fascia
Roof –> Inferior border of IO and TA muscles
Floor –> Mainly inguinal ligament
What are the openings of the Inguinal Canal?
Superficial Inguinal Ring
Deep Inguinal Ring
What are the contents of the Inguinal Canal?
Ilioinguinal Nerve
Spermatiac Cord in males
Round Ligament of the Uterus in females
What are the contents of the Inguinal Canal in males?
the spermatic cord and its coverings + the ilioinguinal nerve. Spermatic cord contains: vas deferens, testicular artery and vein, genital branch of the genitofemoral nerve, lymphatic vessels
What are the contents of the Inguinal Canal in females?
the round ligament of the uterus + the ilioinguinal nerve.
What are the Peritoneum & Peritoneal Folds?
Parietal Peritoneum
Visceral Peritoneum
Omenta (Greater and Lesser)
Ligaments
Mesentery
Mesocolon
What is the Parietal Peritoneum?
lines inside surface of the body wall
What is the Visceral Peritoneum?
covers the surface of internal organs
What is the Omenta (Greater and Lesser)?
Attach stomach & duodenum to adjacent organs
What is the Ligaments?
Attach organ to organ or organ to abdominal wall; associated with omenta
What is the Mesentery?
(double layers of peritoneum) folds that attach organs to abdominal wall (Mesocolon)
What is the Omenta’s (greater & lesser) functions?
- Storage for fat
- Immunity
- Anchoring/tethering organs
(word means apron)
lesser has same function but doesn’t move as much as greater
What is apart of the Greater Omentum?
- Gastrophrenic ligament (tether stomach to diaphragm)
- Gastrosplenic ligament (stomach to spleen)
- Gastrocolic ligament (stomach to colon)
What is apart of the Lesser Omentum?
- Hepatogastric ligament (stomach to liver)
- Hepatoduodenal ligament (find Portal vein, hepatic artery & bile duct)
- Omental (epiploic) foramen
What is the Mesentery?
Double layer of peritoneum that a8aches organs to the posterior abdominal wall (mainly small intestine)
What does the Mesentery contain?
- Contains blood /lymph vessels, fat, nerves
- Makes the organs mobile (good for childbirth)
- Now considered an organ itself!
What is apart of the Peritoneal Cavity & Spaces?
- Greater sac
- Lesser sac
- Omental foramen
What is imp. about the Peritoneal Cavity?
*NO ORGANS are in the peritoneal cavity
What is the Omental foramen’s function?
communication between lesser & greater sacs in the Peritoneal cavity
What are the Retroperitoneal Structures?
S – Suprarenal (adrenal) gland
A – Aorta/IVC
D – Duodenum (except 1st part)
P – Pancreas (except tail)
U - Ureters
C – Colon (ascending and descending)
K - Kidneys
E - Esophagus
R - Rectum
SAD PUCKER
What are the Intraperitoneal Structures?
*Everything else
- Stomach
- Spleen
- Liver & Gallbladder
- Tail of pancreas
- 1st part of duodenum
- Jejunum
- Ileum
- Appendix
- Colon (transverse and sigmoid)
What is Ascites?
EXCESS FLUID in the peritoneal cavity
What is Ascites caused by?
Caused by trauma leading to internal bleeding, hypertension, heart failure, cancer and other pathologies
What does Ascites cause?
Causes PERITONITIS (inflammation of the peritoneum)
What is the treatment of Ascites?
PARACENTESIS aspiration or drainage of the fluid by inserting a needle into the peritoneal cavity
