Abdomen Flashcards
What are the layers of the anterior abdominal wall (superficial to deep)?
- Skin
- Superficial fascia
- Anterior abdominal wall muscles
- Transversalis fascia
- Extraperitoneal connective tissue
- Peritoneum
What are the layers of superficial fascia in the anterior abdominal wall (superficial to deep)? Describe the layout.
- Superficial fatty layer - fascia of Camper’s
- Deep membranous layer - fascia of Scarpa’s
Above the umbilicus, the superficial fascial layer is only fat. Below the umbilicus, the other two layers arise.
What are the 6 muscles of the anterior abdominal wall?
Anterolateral:
- External oblique
- Internal oblique
- Transversus abdominis
Midline:
- Rectus abdominis
- Pyramidalis
- Cremaster muscle
What is the origin of external oblique?
- Ribs (5-12)
What is the insertion of external oblique?
- Pubic tubercle
- Linea alba
- Iliac crest
What is the origin of internal oblique?
- Iliac crest
- Thoracolumbar fascia
- Inguinal ligament
What is the insertion of internal oblique?
- Ribs (10-12)
- Linea alba
- Pubis
What is the origin of transversus abdominis?
- Thoracolumbar fascia
- Inguinal ligament
- Iliac crest
- Ribs (7-12)
What is the insertion of transversus abdominis?
- Linea alba
- Pubic crest
- Pecten pubis
What are the functions of external oblique, internal oblique, and transversus abdominis?
All: Compress and support abdominal viscera
Obliques only: Flexion and rotation of trunk
What is the origin of rectus abdominis?
- Pubic symphysis
2. Pubic crest
What is the insertion of rectus abdominis?
- Ribs (5-7)
2. Xiphoid process
What is the function of rectus abdominis?
Compression of abdominal viscera
What is the origin of pyramidalis?
- Body of pubis
What is the insertion of pyramidalis?
- Linea alba
What is the function of pyramidalis?
Tenses linea alba
What is the origin of cremaster?
- Internal oblique muscle
2. Inguinal ligament
What is the insertion of cremaster?
- Crest of pubis
2. Pubic tubercle
What is the function of cremaster?
Moves the testes
What is the rectus sheath?
Aponeurotic sheath formed by the fusion of the aponeuroses of external oblique, internal oblique, and transversus abdominis.
What are the muscular contents of the rectus sheath?
- Rectus abdominis
2. Pyramidalis
What are the vascular and nerve contents of the rectus sheath?
- Inferior epigastric
- Superior epigastric
- Lower 6 intercostal nerves
Describe the walls of the rectus sheath above the arcuate line.
The anterior layer of the rectus sheath above the arcuate line contains the aponeuroses of the external and internal obliques. The posterior layer of the rectus sheath contains the aponeuroses of the internal oblique and transversus abdominis.
Describe the walls of the rectus sheath below the arcuate line.
The rectus sheath below the arcuate line contains the aponeuroses of the external oblique, internal oblique, and transversus abdominis. The rectus abdominis is not within the rectus sheath; it is in contact with the transversalis fascia.
What are the three lines in the abdomen? Describe them.
- Linea semilunaris - curved tendinous intersection on either side of rectus abdominis
- Linea alba - runs down the midline of the abdomen
- Arcuate line - demarcates the lower limit of the posterior layer of the rectus sheath; where inferior epigastric vessels perforate the rectus abdominis
The inguinal canal is formed in relation to the relocation of the ___ during fetal development.
Gonads
What is a fibrous band that extends from the caudal part of the testis and plays a role in the descent of the testis?
Gubernaculum
What does the gubernaculum do?
Forms a path through the anterior abdominal wall for the processus vaginalis to follow during the formation of the inguinal canal; it then anchors the testis to the scrotum.
What are the layers of the scrotum?
- Skin
2a. Dartos fascia
2b. Dartos muscle - External spermatic fascia
- Cremaster muscle
- Cremasteric fascia
- Internal spermatic fascia
- Tunica vaginalis (parietal and visceral layers)
What is each layer of the scrotum derived from?
- Skin from skin
2a. Dartos fascia from Camper’s fascia
2b. Dartos muscle from Scarpa’s fascia - External spermatic fascia from external oblique
- Cremaster muscle from internal oblique
- Cremasteric fascia (n/a)
- Internal spermatic fascia from transversalis fascia
- Tunica vaginalis from peritoneum
Which part of the abdominal wall does not become a part of the scrotum?
Transversus abdominis
The ___ is an oblique passage in the lower part of the anterior abdominal wall just above the medial half of the inguinal ligament.
Inguinal canal
How long is the inguinal canal?
4cm
In what three directions is the inguinal canal directed?
Downward, forward, medially
In which sex is the inguinal canal larger?
Male
Where is the deep inguinal ring located?
Transversalis fascia
What passes through the deep inguinal ring to enter the inguinal canal?
Spermatic cord (males), round ligament of uterus (females)
What is the other name for the inguinal triangle?
Hesselbach’s triangle
What are the medial, lateral, and inferior boundaries of Hesselbach’s triangle?
- Medial: linea semilunaris
- Lateral: inferior epigastric vessels
- Inferior: inguinal ligament
What is a common site of a direct inguinal hernia? Why?
Hesselbach’s triangle; it is an area of potential weakness
Which abdominal muscle has low arching fibers?
Internal oblique
Which abdominal muscle has high arching fibers?
Transversus abdominis
What forms the conjoint tendon?
Internal oblique and transversus abdominis
What contains the superficial inguinal ring?
External oblique aponeurosis
What forms the inguinal ligament?
External oblique
What structures pass through the superficial inguinal ring?
Spermatic cord (males) or round ligament (females), and ilioinguinal nerve
Describe the boundaries of the inguinal canal (roof, floor, anterior wall, posterior wall)
- Roof: internal oblique and transversus abdominis
- Floor: inguinal ligament
- Anterior wall: external oblique aponeurosis and internal oblique fibers (lateral 1/3)
- Posterior wall: transversalis fascia and conjoint tendon (medial 1/3)
What are the three coverings of the spermatic cord?
- External spermatic fascia
- Cremaster muscle and fascia
- Internal spermatic fascia
What are the three arteries of the spermatic cord?
- Testicular artery
- Cremasteric artery
- Artery of vas
What are the three “V” structures of the spermatic cord?
- Vas deferns
- Pampiniform venous plexus
- Vestiage of processus vaginalis
What are the three nerves of the spermatic cord?
- Genital branch of genitofemoral nerve
- Sympathetic plexus around testicular artery
- Sympathetic plexus around artery of vas
What are the two types of inguinal hernia?
- Indirect inguinal hernia
2. Direct inguinal hernia
What is a hernia?
Protrusion of abdominal contents (usually intestine) within a sac of peritoneum into the inguinal region
Why are inguinal hernias more common in men?
Men have a larger inguinal canal
Describe the location of an indirect inguinal hernia.
Passes through the deep ring, inguinal canal, and superficial ring; found lateral to inferior epigastric artery
Describe the location of a direct inguinal hernia.
Passes through the posterior wall of the inguinal canal (through the inguinal triangle); found medial to inferior epigastric artery
Which type of hernia is more common?
Indirect inguinal hernia
Which type of hernia is congenital? Which is acquired?
Congenital - indirect inguinal hernia
Acquired - direct inguinal hernia
Which type of hernia commonly enters the scrotum?
Indirection inguinal hernia
More than ___ of hernias are indirect; indirect hernias are ___ times more common in males than in females.
2/3; 20
In the suprapubic region, the parietal peritoneum is raised into 5 folds by 5 structures that run in the extraperitoneal tissue. What are these folds?
- Median umbilical fold
- 2 medial umbilical folds
- 2 lateral umbilical ligaments
What raises the median umbilical fold?
Median umbilical ligament (fibrosed urachus)
What raises the medial umbilical folds?
Medial umbilical ligaments (obliterated umbilical arteries)
What raises the lateral umbilical ligaments?
Inferior epigastric arteries
Name the 9 intraperitoneal viscera.
- Stomach
- Liver
- Spleen
- 1st part of Duodenum
- Jejunum
- Ileum
- Appendix
- Transverse colon
- Sigmoid colon
Name the 10 retroperitoneal viscera
- Esophagus
- Aorta
- Pancreas
- Duodenum (2nd part)
- Ascending colon
- Descending colon
- Kidney
- Suprarenal glands
- Ureter
- Rectum
What are the two layers of the peritoneum?
- Parietal
2. Visceral
What are the three types of peritoneal folds (double layers of peritoneum)? Describe them.
- Ligament - connects an organ with another or with the anterior abdominal wall
- Omentum - passing from the stomach and first part of duodenum to adjacent organs
- Mesentery - invagination of the peritoneum by the intestine
What are the two peritoneal cavities?
- Greater sac
2. Lesser sac
How are the peritoneal cavities connected?
Omental/epiploic foramen (of Winslow)
With what are the peritoneal cavities filled?
Serous fluid
What is the vertebral level of the celiac trunk?
T12
What is the vertebral level of the superior mesenteric artery?
L1
What is the vertebral level of the inferior mesenteric artery?
L3
What are the three unpaired branches of the abdominal aorta?
- Celiac trunk
- Superior mesenteric artery
- Inferior mesenteric artery
What are the three branches of the celiac trunk?
- Splenic artery
- Left gastric artery
- Common hepatic artery
What are the three branches of the superior mesenteric artery?
- Ileocolic artery
- Right colic artery
- Middle colic artery
What are the three branches of the inferior mesenteric artery?
- Left colic artery
- Sigmoid branches
- Superior rectal artery
Which branch of the celiac trunk runs a tortuous course?
Splenic artery
What are the two ends of the stomach?
- Cardiac
2. Pyloric
What are the two borders of the stomach?
- Greater curvature
2. Lesser curvature
What is contained in the epiploic foramen (of Winslow)?
- Portal vein
- Hepatic artery
- Hepatic duct
Why is the greater omentum known as the policeman of the abdomen?
The greater omentum is very fatty and helps prevent the spread of infection.
What three ligaments comprise the greater omenum?
- Gastrosplenic
- Gastrophrenic
- Gastrocolic
What two ligaments comprise the lesser omentum?
- Hepatogastric
2. Hepatoduodenal
What 9 structures are found in the stomach bed?
- Pancreas
- Spleen
- Transverse colon (part)
- Peritoneal aspect of duodenum
- Left kidney
- Left suprarenal gland
- Left colic flexure
- Left crus of diaphragm
- Splenic artery
What are the 5 peritoneal ligaments of the liver?
- Falciform ligament
- Coronary ligament
- Right triangular ligament
- Left triangular ligament
- Lesser omentum
What are the 5 fissures of the liver?
- Fissure for ligamentum venosum
- Fissure for ligamentum teres
- Fossa for gall bladder
- Fissure for inferior vena cava
- Porta hepatis
What separates the liver anatomically into the right (plus caudate and quadrate) and left lobes?
Ligamentum teres and ligamentum venosum
What separates the liver functionally into the right and left (plus caudate and quadrate) lobes?
Gall bladder fossa and fissure for IVC
What is included in the porta hepatis?
- Portal vein (most posterior)
- Hepatic artery
- Hepatic duct (most anterior)
VAD
What is the function of the gall bladder?
Stores bile secreted from the liver and releases bile into the small intestine via the cystic duct
What is a common site of gall stones?
Hartmann’s pouch (sac on the posteromedial wall)
What part of the gall bladder is most tender in the case of acute gall bladder inflammation?
Fundus
Describe the path of bile to the small intestine.
The right and left hepatic ducts of the liver combine to form the common hepatic duct. The cystic duct empties into the common hepatic duct to form the common bile duct. The main pancreatic duct (of Wirsung) also empties into the common bile duct. The common bile duct empties into the second part of the duodenum.
What controls the release of bile into the small intestine?
Sphincter of Oddi, found at the ampulla of Vater
What are the two functions of the pancreas and what does it release?
- Endocrine (insulin and glycogen)
2. Exocrine (digestive enzyme)
What additional duct is found in some pancreases?
Accessory pancreatic duct (of Santorini)
What is the function of the spleen?
Hematopoietic function
What is transmitted by the hilum of the spleen?
Splenic vessels; gives attachment to gastrosplenic and splenorenal ligaments
What are the boundaries of the small intestine?
Pylorus of the stomach to the ileocecal junction
What are the boundaries of the first part of the small intestine?
The duodenum extends from the pylorus of the stomach to the duodenojejunal flexure.
Describe the positions of the parts of the duodenum as they relate to the vertebra.
- 1st part - anterolateral to L1
- 2nd part - lies right to L2-L3
- 3rd part - lies horizontal anterior to L3
- 4th part - ascends to the left of L3 to L2
Describe the fan-shaped mesentery of the jejunum and ileum.
- Attached border (root) - 6 inches long, crosses 3rd part of duodenum, aorta, IVC, right ureter, right psoas major
- Free border - 6 meters long, encloses loops of jejunum and ileum
List the components of the large intestine in order.
- Cecum
- Appendix
- Ascneding colon
- Right (hepatic) colic flexure
- Transverse colon
- Left (splenic) colic flexure
- Descending colon
- Sigmoid colon
- Rectum
- Anal canal
What are omental appendices and where are they absent in the large intestine?
Small pouches of peritoneum filled with fat; absent in cecum, appendix, and rectum
Describe the taeniae coli and the haustra.
The taeniae coli are three bands of thickened longitudinal muscle layer that begin at the base of the appendix and end at the sigmoid colon. The haustra lie between the taeniae coli as three rows of pouches where the colon bulges.
What are the three openings of the diaphragm, where do they lie, and at what level do they occur?
- Caval hiatus (T8), lies in central tendon
- Esophageal hiatus (T10), lies in right crus
- Aortic hiatus (T12), lies bethind or between 2 crura
What does the caval hiatus transmit?
Inferior vena cava and sometimes the right phrenic nerve
What does the esophageal hiatus transmit?
Esophagus and vagus nerve (anterior and posterior trunks)
What does the aortic hiatus transmit?
Aorta, thoracic duct, azygos vein, and sometimes the greater splanchnic nerve
What are the three parts of the diaphragm?
- Sternal part
- Costal part
- Vertebral part
What are the origins of the three parts of the diaphragm?
- Sternal part: xiphoid process
- Costal part: lower 6 costal cartilages
- Vertebral part: crura and ligaments
From what vertebra do the right and left crus originate?
Right crus: L1-L3
Left crus: L1-L2
What types of hormones are produced by the cortex and medulla of the suprarenal glands?
Cortex: three types of steroid hormone
Medulla: epinephrine and norepinephrine
Describe the components of the kidneys.
The cortex is the outer portion of the kidney that projects into the medullary region as renal columns between the renal pyramids. The medulla is the inner portion of the kidney and contains 1-2 million nephrons and 8-12 pyramids.
Describe the flow of fluid from the kidney into the urinary bladder.
Fluid flows from the renal pyramids into the minor calyx, which flows into the major calyces. This empties into the renal pelvis of the ureter, which empties into the urinary bladder.
What are the three sites of constriction in the ureter?
- Uretero-pelvic junction
- Pelvic inlet
- Ureterovesicular junction
What is the narrowest part of the ureter?
Ureterovesicular junction
What innervates the muscles of the abdomen (generally and specifically)?
Generally: thoracic spinal nerve roots
Specifically:
- External oblique and rectus abdominis - T7-T12
- Internal oblique and transversus abdominis - T7-L1
What are the 6 major nerves of the lumbar plexus?
- Iliohypogastric nerve
- Ilioinguinal nerve
- Genitofemoral nerve
- Lateral femoral cutaneous nerve
- Obturator nerve
- Femoral nerve
I, I Get Leftovers On Fridays
What does the iliohypogastric nerve innervate?
- Internal oblique
- Tranversus abdominus
- Posterolateral gluteal skin in pubic region
What muscle do the iliohypogastric and ilioinguinal nerves pierce?
Transversus abdominis
What does the ilioinguinal nerve innervate?
- Internal oblique
- Transversus abdominus
- Skin on upper medial thigh, over root of penis/anterior scrotum, over mons pubis and labium majora
What are the branches of the genitofemoral nerve?
- Genital branch
2. Femoral branch
What does the genital branch of the genitofemoral nerve innervate?
- Cremaster muscle
2. Skin of anterior scrotum, skin of mons pubis and labium majora
What does the femoral branch of the genitofemoral nerve innervate?
- Skin of upper anterior thigh
What does the obturator nerve innervate?
- Muscles in medial compartment of thigh (3 adductors, obturator externus, gracilis)
- Skin on medial aspect of thigh
What does the femoral nerve innervate?
- Muscles in anterior compartment of thigh (Quadriceps - 4 muscles and iliopsoas)
- Pectineus
- Articularis genus
- Iliacus
- Sartorius
- Skin on anteromedial thigh, medial side of leg, foot