Anatomy Lecture 2 -- Abdomen 2 Flashcards
6 landmark lines and planes of the abdomen
- Midclavicular (or midinguinal) line
- Transpyloric plane
- Subcostal plane
- Transumbilical plane
- Intertubercular plane
- Interspinous plane
Describe the precise location of the midclavicular (or midinguinal) line
- Halway point of the clavicle
- Bisects the inguinal ligament
Describe the precise location of the transpyloric plane
- Halfway between the jugular notch and upper border of the pubic symphasis
- At the tip of the 9th costal cartilages
- Level of L1
Describe the precise location of the subcostal plane
- Lower border of the 10th costal cartilage
- Level of the IVD between L2 and L3
Describe the precise location of the transumbilical plane
Passes through the umbilicus
Describe the precise location of the intertubercular plane
- Level of the iliac tubercles (5 cm posterior to the ASIS)
- Level of L5
Describe the precise location of the interspinous plane
- Passes through the anterior superior iliac spines (ASIS)
- Level of the sacral promontory
Locate the abdominal quadrants
What defines the abdominal quadrants
Midline and transumbilical plane
Organs contained in the right upper abdominal quadrant
Liver and gallbladder
Organs contained in the left upper abdominal quadrant
Stomach and spleen
Organs contianed in the right lower abdominal quadrant
- Cecum
- APpendix
- Ascending colon
- Small bowel
Organs contained in the left lower abdominal quadrant
- Descending and sigmoid colon
- Small bowel
6 abdominal regions
From top right to bottom left:
- Right hypochondriac region
- Right lumbar region
- Right iliac (inguinal region)
- Epigastric region
- Umbilical region
- Hypogastric region
- Left hypochondriac region
- Left lumbar region
- Left iliac (inguinal) region
What defines the abdominal regions?
Midclavicular lines and subcostal and intertubercular planes
Organs contained in the right hypochondriac region
Liver and hepatic flexure
Organs contained in the right lumber region
Ascending colon
Organs contained in the right iliac (inguinal) region
Cecum
Organs contained in the epigastric region
Pylorus
Organs contained in the umbilical region
Jejunum
Organs contained in the hypogastric region
Rectum and bladder
Organs contained in the left hypochondriac region
Spleen and splenic flexure
Organs contained in the left lumbar region
Descending colon
Organs contained in the left iliac (inguinal) region
Sigmoid colon
Define the peritoneal cavity
A potential space between the parietal peritoneum and the visceral peritoneum
Volume of fluid secreted by the peritoneum and its purpose
- 50 mL fluid secreted per day
- Acts as a lubricant and has anti-inflammatory properties
Define intraperitoneal organs
- Organs nearly totally covered by visceral peritoneum
- Not actually inside the peritoneal cavity, but project into the peritoneal cavity
- Are attached to the body wall and other organs by mesenteries and ligaments
11 intraperitoneal organs
- Liver
- Stomach (ST)
- Spleen
- Duodenum (1st part)
- Small intestines (SI)
- Cecum
- Appendix
- Transverse colon (TC)
- Sigmoid colon
- Rectum (upper 1/3)
- Fallopian tubes/ovaries
Define retriperitoneal organs in general
Organs that have peritoneum on only their anterior side
Define primary retroperitoneal organs
Organs that were always posterior to the peritoneum throughout development
Define secondary retroperitoneal organs
Organs that were once suspended within the abdominal cavity by mesentery, but migrated posterior to the peritoneum during the course of embryogenesis to become retroperitoneal
6 primarily retroperitoneal organs
- Adrenal glands
- Kidneys
- Ureter
- Bladder
- Aorta
- Inferior vena cava
3 organs (and their specific parts) that are secondarily retroperitoneal
- Head and neck of the pancreas (not the tail)
- Second and third portions of the duodenum (not the first or fourth)
- Ascending and descending portions of the colon (not transverse or sigmoid)
Define mesentery
Double sheets of peritoneal membrane that suspend portions of the digestive tract within the peritoneal cavity. Serous membrane that connects the parietal peritoneum with the visceral peritoneum
Define the lesser omentum and its function
Separate portion of peritoneum that stabilizes the position of the stomach and provides an access route for blood vessels and other structure entering or leaving the liver
Define the greater omentum
Hangs like an apron from the lateral and inferior borders of the stomach
Define the mesentery proper
A thick mesenterial sheet that provides stability to the small intestine, but permits some independent movement
Define the transverse mesocolon
Mesentery that supports the transverse colon, extending from pancreas on the posterior wall to the transverse colon
Define the sigmoid mesocolon
Mesentery that supports the sigmoid colon
Describe the characteristics of the mesentery proper
- Fan-shaped suspensory ligament of jejunum and ileum
- Approx. 15 cm in length
- Line of attachment is oblique - extends from the point of termination of the duodenum to the base of the cecum
Define the paraduodenal fossa
Hole in the peritoneum through which the duodenum passes to become the jejunum and thus intraperitoneal
Situate the paracolic gutters (recesses)
Right = superolateral aspect of the hepatic flexure to the lateral aspect of the ascending colon, and around the cecum
Significance of the paracolic gutters
Bile, pus or blood released from viscera anywhere along its length may run along the gutter and collect in sites quite remote from the organ of origin
Effect of supine position for patients with infected fluid from the right iliac fossa
Contents may ascend in the gutter to enter the lesser sac
Effect of sitting position for patients with infected fluid from the stomach, duodenum or gallbladder
May run down the gutter to collect in the right iliac fossa or pelvis and may mimic acute appendicitis or form a pelvic abscess
Define the gastrocolic ligament (GC)
A portion of greater omentum (GO) that stretches from the greater curvature of the stomach to the transverse colon. It forms part of the anterior wall of the lesser sac
2 parts of the lesser omentum
- Hepatogastric ligament (HG)
- Hepatoduodenal ligament (HD)
Function of the hepatogastric ligament
Connect the liver to the lesser curvature of the stomach
Function of the hepatoduodenal ligament
- Connect the liver (porta hepatis) to the duodenum
- Contains the proper hepatic artery, hepatic portal vein, common bile duct (portal triad)
Spatial relations of the epiploic (omental) foramen (of Winslow)
- Anterior = hepatoduodenal ligament (contains portal triad)
- Posterior = IVC
- Superior = Caudate lobe of liver
- Inferior = Duodenum
Spatial relations of the lesser sac
- Anterior
- Lesser omentum
- Stomach
- Gastrocolic ligament
- Posterior
- Pancreas
- Left kidney
- Left adrenal gland
- Right
- Epiploic foramen
- Left
- Gastrosplenic ligament
- Lienorenal ligament
What does the lienorenal (splenorenal) ligament contain
- Splenic vessels
- Tail of the pancreas
What does the gastrosplenic ligament contain
- Short gastric vessels
- Left gastroepiploic vessels
Define the falciform ligament
Sickle-shaped ligament that attaches the liver to the anterior body wall. Broad and thin antero-posterior peritoneal fold
Define the ligamentum teres
A remnant of the umbilical vein of the fetus
3 ligaments of the liver
- Coronary ligament
- Triangular ligament
- Falciform ligament
Define the urachus
A fibrous remnant of the allantois, a canal that drained bladder of the fetus in the umbilical cord
