Nov 13 - Abdomen I: Abdominal Wall and Cavity Flashcards
Name the four boundaries of the abdomen
The superior, posterior, anterolateral and inferior
What is the superior border of the abdomen?
The diaphragm (fifth intercostal space)
What is the posterior border of the abdomen?
The lumbar vertebrae and quadratus lumborum muscles
What is the anterolateral border of the abdomen?
The muscles of the abdominal wall
What is the inferior border of the abdomen?
The pelvic brim
What is the functional difference between the thorax and the abdomen?
The thorax houses organs to keep you alive (heart, lungs, etc.). The abdomen houses organs for the harvesting of feul (stomach, intestines, etc.)
What is the main function of the abdomen?
It houses and protects the abdominal viscera - digestive organs, kidneys, spleen
Name the five functions of the abdominal muscles
I. Protection of abdominal viscera
II. Movement of the trunk
III. Compressing the abdominal viscera
IV. Allow expansion of abdominal cavity (parturition, etc.)
V. Expelling abdominal contents (micturition, defecation, parturition, vomiting) - increase intra-abdominal pressure
Name the four abdominal quadrants
The right and left upper quadrants and the right and left lower quadrants
How are the four abdominal quadrants divided?
The right and left quadrants are divided down the midline (median plane). The upper and lower quadrants are divided through the transumbilical plane
Name the three upper abdominal regions
The left and right hypochondriac region and the epigastric region
Name the three middle abdominal regions
The left and right lumbar (flank) region and the umbilical region
Name the three lower abdominal regions
The left and right iliac (inguinal) region (groin areas) and the hypogastric (pubic) region
What divides the upper and middle regions?
The subcostal plane
What divides the middle and lower regions?
The transtubercular plane
What divides the left and right regions from the middle (vertical) region?
The midclavicular planes
Name the layers of the anteriolateral abdominal wall from superficial to deep
Skin, superficial fascia, deep (investing) fascia, muscles, transversalis fascia, extraperitoneal fat/fascia and peritoneum
What makes up the superficial fasica?
The camper fascia and the scarpa fascia
What is the camper fascia?
The superficial fatty layer of subcutaneous tissue
What is the scarpa fascia?
The deep membranous layer of subcutaneous tissue
Name the four muscles of the anterolateral abdominal wall
The rectus abdominus, the exteral oblique, the internal oblique, the transversus abdominus
Name the two muscles (as well as their function) of the posterior abdominal wall
The quadratus lumborum (stabilizes the vertebal column)
The psoa major (combines with the iliacus to form the iliopsoas, hip flexor
What innervates the anterolateral abdominal wall?
The ventral rami of spinal nerves T7-L1.
Includes intercostal nerves (T7-T11), subcostal nerve T12, iliohypogastric and ilioinguinal nerves L1
Name the primary blood vessels (arteries and veins) of the anterolateral abdominal wall
The superior epigastric vessels and branches of the musculophrenic vessels from the internal thoracic vessels.
The inferior epigastric and deep circumflex vessels from the external iliac vessels
What is the inguinal canal?
4 cm long tube-like space within the lower part of the anterior abdominal wall
Where is the inguinal canal found?
Begins at the deep inguinal ring and ends at the superficial inguinal ring
What makes the floor of the inguinal canal?
The inguinal ligament
What makes the anterior wall of the inguinal canal?
The external oblique aponeurosis
What makes the roof of the inguinal canal?
It’s formed by arched fibres of the internal oblique and transversus abdominis muscles
What makes the posterior wall of the inguinal canal?
The transversalis fascia (laterally) and conjoint tendon (medially)
Describe the superficial inguinal ring
Triangular opening in the external oblique aponeurosis
Describe the deep inguinal ring
Opening in the transversalis fascia
Name the contents of the inguinal canal in males
The spermatic cord and its coverings
The ilioinguinal nerve
Name the contents of the inguinal canal in females
The round ligament of the uterus
The ilioinguinal nerve
Name the contents of the spermatic cord
The vas deferens, the testicular artery and vein, the genital branch of the genitofemoral nerve and the lympatic vessels
What is the role of the ilioinguinal nerve?
Sensory innervation of the scrotum and the labia majora
What is the peritoneum?
Transparent membrane that covers most (but not all) abdominal organs. It secretes peritoneal fluid that lubricates the organs and prevents friction
Describe the parietal and visceral peritoneum
The parietal peritoneum lines the abdominal wall. The visceral peritoneum covers the viscera
Name the two main divisions of the peritoneal cavity
The greater sac (largest part of the cavity) and the lesser sac (smaller part)
What is the greater omentum? Describe it
It’s a double layer of peritoneum, impregnated with fat and blood vessels. It attaches to the stomach and transverse colon. The inferior border is free. It hangs down like an apron, covering the abdominal viscera
What is the role of the of the greater omentum?
It prevent organs from sticking to the anterior abdominal wall or other each other (adhesions are bad). It’s also very mobile, allowing it to migrate and wrap around an inflamed or infected organ (prevents the infection from spreading; ex. appendicitis)
Name the three parts of the greater omentum
The gastrophrenic ligament
The gastrosplenic ligament
The gastrocolic ligament
Name the opening to the lesser sac
The epiploic foramen
What is the lesser sac
Aka the omental bursa. It is a pouch found dorsal to the stomach. It communicates with the greater sac via the epiploic foramen
What is the problem with the lesser sac
Because the inferior recess of the lesser sac extends a considerable distance, infectious material from abscesses can collect here (peritonitis)
What is the lesser omentum? Describe it
It’s a double layer of peritoneum. It’s made up of hepatoduodenal and hepatogastric ligaments (the hepatoduodenal ligament contains important blood and bile vessels going to and from the liver)
What is a peritoneal ligament?
A double layer of peritoneum
What connects the liver to the anterior abdominal wall?
The falciform ligament
What is the mesentary?
It’s a double layer of peritoneum that attaches organs to the posterior abdominal wall (mainly small intestine). It is a very mobile structure (makes the organs mobile). It contains blood/lymph vessels, fat and nerves.
What does intraperitoneal mean?
Intraperitoneal organs are covered by visceral peritoneum
What does retroperitoneal mean?
Retroperitoneal organs lie between the parietal peritoneum and the posterior abdominal wall
Name the intraperitoneal organs
The stomach, the spleen, the liver and gallbladder, the small intestine (jejunum, ileum and a small part of the duodenum) and the large intestine (transverse colon, sigmoid colon)
Name the retroperitoneal organs
The kidneys and suprarenal glands (adrenal glands), the pancreas, most of the duodenum and the large intestine (ascending and descending colon)
