Anatomy - General Abdomen Flashcards
What are the superior and inferior boundaries of the abdomen?
Superior: diaphragm
Inferior: pelvic region (continuous with pelvic cavity at the pelvic inlet)
What are the anterior and posterior boundaries of the abdomen?
Anterior: above = thoracic cage; below = abdominal muscles (rectus abdominus, external/internal obliques, transverse abdominis muscles, fascia)
Posterior: vertebral column and posterior/inferior ribs
What are the lateral boundaries of the abdomen?
Muscles of the flank
What are the 3 spaces of the abdominal cavity?
1) Peritoneal space/Peritoneum: abdominal lining
2) Retroperitoneal space: behind peritoneal space (kidneys)
3) Pelvic space: organs contained within pelvic area itself
Describe the anterior abdominal wall from most superficial to deep.
Skin Superficial fascia Deep fascia Extraperitoneal fascia Parietal peritoneum
Where do the rectus abdominus muscles sit?
Vertical midline
-responsible for “six pack”
What are the 3 muscular layers of the abdominal wall that form a tube and give body continuity and shape?
1) External oblique (“hands in pocket”)
2) Internal obliques (“hands on tits”)
3) Transversus abdominus (wraps around)
What is ITB syndrome?
Inflammation of the IT band which causes pain on the lateral side of the hip
What are the muscles of the posterior abdominal wall?
Psoas major and minor
Where does the skin near the midline of the abdomen get its blood supply from?
Superior epigastric artery (branch of internal thoracic artery) and Inferior epigastric artery (branch of external iliac artery)
Where does the skin of the flanks get its blood supply from?
Branches from the intercostal, lumber and deep circumflex arteries
Where does abdominal venous blood go?
Network of veins that radiate from the umbilicus
Where does the abdominal venous blood drain above the umbilicus? Below the umbilicus?
- Above into axillary vein through lateral thoracic vein
- Below into femoral vein through superficial epigastric and saphenous vein
What is the importance of the paraumbilical veins?
They form a portal system venous anastomosis (liver)
What is caput medusae?
When the portal veins are obstructed, the superficial veins around the umbilicus and paraumbilical veins become grossly distended
What is the cause of caput medusae?
Cirrhosis: liver doesn’t work and is clogged with fatty tissue -> venous system is compromised and venous blood pools and causes distention and blueish discoloration in superficial veins surrounding umbilicus
-seen in hepatitis, alcoholics, liver cancer, liver transplant
What conditions would cause caput medusea?
Portal obstruction, portal hypertension, fatty liver
What do the nerves of the anterior abdominal wall innervate?
The skin, muscles, parietal peritoneum
Where are the nerves of the anterior abdominal wall derived from?
Anterior rami of lower 6 thoracic and 1st lumbar nerves
What does inflammation of the parietal peritoneum (peritonitis) cause?
Pain in the overlying skin -> nerves activated -> increased muscle tone over that area -> muscle rigidity
What will you see with peritonitis?
Muscle rigidity where the peritoneum is being inflamed, generally caused by injury or illness of hollow organ (i.e. appendix)
Where does lymph drainage of the skin of the anterior abdominal wall above the umbilicus go? Below the umbilicus?
- Upward to anterior axillary nodes (pectoral group of nodes)
- Downward and laterally to superficial inguinal nodes
What could swelling in the groin be caused by?
Infection –> Lymph node blockage
What is the rectus sheath?
Long fibrous sheet that encloses the rectus abdominis
What nerves does the rectus sheath contain?
Anterior rami of lower 6 thoracic nerves
What forms the rectus sheath?
The aponeurosis of 3 lateral muscles:
1) External oblique
2) Internal oblique
3) Transverse abdominus
What vasculature does the rectus sheath contain?
The superior and inferior epigastric vessels and lymphatic vessels
What is the most anterior part of the rectus sheath? The most posterior part?
Anterior - aponeurosis of the external oblique muscle
Posterior - the thoracic wall (5th, 6th and 7th costal cartilages)
What can cause hernias in the rectus sheath?
Surgeries in the midline
Pregnancies
How is the rectus muscle enclosed within the rectus sheath?
The aponeurosis of the internal oblique splits to enclose the rectus muscle
At what level does the aponeurosis of the internal oblique split to enclose the rectus muscle?
Between the costal margin (between the ribs) at the level of the antero-superior iliac spine (at level of iliac crests)
-at this level the aponeurosis of the external oblique is directed in front of the rectus abdominus and the transversus is directed behind it
How is the rectus sheath attached to the rectus muscle?
Only anteriorly, by the muscles tendinous intersections
At rectus sheath between level of anterior superior iliac spine and pubis where are the 3 aponeurosis directed?
All 3 are directed in front
What does the esophagus do?
Carry food and liquid into the stomach
What are the three parts of the small intestine?
1) Duodenum
2) Jejunum
3) ilium
What are the parts of the large intestine?
Cecum (including appendix), ascending colon, transverse colon, descending colon, sigmoid colon
What separates the abdominal cavity from the thoracic cavity?
Diaphragm
What lines the abdominal cavity?
Peritoneum
What is a hiatal hernia?
Defect in abdominal cavity -> Intestines enter thoracic cavity through a hole in the diaphragm - patients present with chest pain that is alleviated by sitting up
What is the largest concern with trauma and LUQ pain?
Splenic injury
-Mono causes spleen enlargement -> NO contact sports x 3 months to avoid trauma and ruptured spleen
What is rebound tenderness?
Pain felt upon removal of pressure from the abdomen, indication of parietal pain
What is diverticulitis?
Inflammation in the out pockets of the colon, generally when stool gets stuck in them (the individual out pockets are called diverticulosis)
What would RUQ pain indicate?
- Liver: liver lac (traumatic)
- Gall bladder: cholecystitis (atraumatic)
What would RLQ pain indicate?
- Appendix: rebound tenderness
- Colon: colitis, diverticulitis
- Pelvic inflammation: diffuse tenderness
- Problem with ureter/bladder/gonads
What would LUQ pain indicate?
- Spleen: rigidity under ribs (traumatic)
- Stomach
What would LLQ pain indicate?
- Colon: colitis, diverticulitis
- Pelvic inflammation: diffuse tenderness
What is a possible risk of repeated STD infection?
PID, which causes diffuse pelvic pain
What is visceral pain caused by?
Stretching of a hollow organ or capsule of a hollow organ
-dull and starts first
Where is visceral pain of the foregut organs felt?
Stomach, duodenum, biliary tract -> felt in EPIGASTRIC region
Where is visceral pain of the midgut organs felt?
Most small bowel, appendix, cecum -> felt in PERIUMBILICAL area
Where is visceral pain of the hindgut organs felt?
Most of colon, including sigmoid and intraperitoneal portion of GU tract -> felt in SUPRAPUBIC or HYPOGASTRIC area
What is parietal pain?
Caused by irritation of fibers that innervate the parietal peritoneum
- comes after visceral pain
- can be localized where inflammation is
- rebound pain
What is referred pain?
Pain or discomfort perceived at a site distant from the affected organ because of overlapping transmission pathways
-visceral pain
What are classical examples of referred pain?
- Sub-diaphragmatic irritation
- Gynecologic pathway
- Biliary tract disease
- MI
- Uretral obstruction
- Aortic aneurysm (referred pain straight to the back)
What is the role of hollow organs?
Allow materials to pass through (stomach, large intestine, small intestine) or act as holding tanks (gall bladder, urinary bladder)
When are hollow organs at less risk for injury?
When they are empty
What classifies solid organs?
Significant blood supply - liver, spleen, kidney, pancreas, ovaries and testes
What is the risk of injury to solid organs?
High risk of injury - bruising and tearing
How do you palpate the liver?
Place fingers below RT-costal margin and press firmly
-checking for rigidity, masses, tenderness, size (enlargement present in hepatic disease)
How do you palpate the spleen?
Check for enlargement under LT-rib cage
-be careful when suspicious of pt having Mono because spleen may be enlarged
What is the main cause of trauma to kidneys?
Mountain biking –> shock of riding bike itself
What does it mean to percuss for tissue density?
Lightly place one hand over abdomen (palm down) and index/middle fingers of opposite hand tap DIP joints
- normal: solid organs -> dull thump/resonant sound; hollow organs -> hard echo/sound hollow
- positive: hard, sound echoing over areas that should sound hollow
Which kidney is more inferior?
Right kidney (because of liver)
What is rigidity?
Muscle guarding that occurs secondary to blood accumulation
-parietal pain
What is a hernia?
Protrusion of an organ or part of an organ through a defect in the wall of the cavity normally containing it
What is an indirect inguinal hernia?
A hernia that passes through the path of the inguinal canal; pass through both deep and superficial inguinal rings and into the scrotum
- Congenital
- Mass is lateral to inferior epigastric artery
What is a direct inguinal hernia?
A hernia that bulges through a weakness in the abdominal wall
- Acquired
- Mass is medial to inferior epigastric artery
- Less common; associated with heavy lifting, straining due to constipation, coughing or prostatic enlargement
Which type of inguinal hernia is more common?
Indirect - 75% inguinal hernias and 3x more in males
What is a reducible hernia?
A hernia that can be pressed back into place (reduced) manually
What is an incarcerated/irreducible hernia?
A hernia that cannot be manually reduced - as the intestine constantly slides up and down, adhesions form and the hernia can’t go back into place because scar tissue limits the movement of the hernia
What is a strangulated hernia?
When the adhesions get very bad, the intestine twists and the hernia becomes strangulated
-Causes: ischemia, inflammation, obstruction and necrosis
Groin hernias are found in what percent of the population?
5% of the MALE population
Groin hernias are what percent of all hernia cases?
86%
Are groin hernias more prevalent in males or females?
5x more often in males than females
What percentage of groin hernias are inguinal and femoral?
Inguinal = 96% Femoral = 4%
If a left inguinal hernia is present, what is the probability that there is an occult right inguinal hernia?
25%
- occult = there but asymptomatic
- common in children and elderly men
What is a femoral hernia?
Intestinal herniation through the femoral canal
- Gender predisposition: female by 3:1 ratio
- Associated with increased intraabdominal pressure, common in elderly women
Where does the femoral canal lie?
Immediately medial to the femoral vein
What is an incisional hernia?
A hernia that develops in the scar of a prior laparotomy or drain site
What are 3 risks for postoperative hernia development?
1) Wound dehiscence (when contents under the sutures protrude; let it heal by 3rd intention- from the inside out)
2) Malnutrition
3) Obesity
What are potential complications of an incisional hernia?
Bowel incarceration, strangulation, small bowel obstruction
What should you clean an open wound with?
Normal saline
-NOT hydrogen peroxide (which would cause the wound to swell and heal poorly)
