E2B Flashcards
liver
located in upper part of abdominal cavity, immediately inferior to diaphragm (right hypochondriac, epigastric and left hypochondriac regions)
almost entirely under cover of ribs and costal cartilages
divided into 2 unequal lobes (right and left) by falciform ligament
gallbladder
pear-shaped sac adherent to undersurface of right lobe of liver; stores and concentrates bile
esophagus
connects pharynx to stomach, begins in neck and ends in abdomen, most of it is located in mediastinum
pierces diaphragm slightly to left of midline, at the level of T10, after a short course in abdomen, it becomes continuous with stomach
abdominal part of esophagus is located posterior to left lobe of liver
stomach
dilated part of alimentary canal between esophagus and small intestine
located in left hypochondriac, epigastric and umbilical regions (much of it under cover of ribs and costal cartilages)
orifices: cardial (communicates with esophagus) and pyloric (communicates with duodenum)
borders: lesser curvature (right) and greater curvature (left)
small intestine
begins at pyloric orifice and terminates at ileocecal junction (where small intestine joins large intestine)
parts: duodenum, jejunum and ileum
duodenum
deeply placed (most of it lies posterior to peritoneal sac), located in epigastric and umbilical regions
C-shaped tube that surrounds head of pancreas, begins at pyloric orifice and terminates at duodenojejunal flexure, where it bends forward to become continuous with jejunum
4 parts: 1st (superior), 2nd (descending), 3rd (horizontal, inferior or transverse) and 4th (ascending)
jejunum and ileum
together measure about 20 feet (6 meters) in length; more mobile than duodenum
jejunum begins at duodenojejunal flexure and ileum ends at ileocecal junction (where it joins large intestine)
approximately proximal two-fifths form jejunum and distal three-fifths form ileum
coils of jejunum occupy upper part of infracolic compartment of abdominal cavity
coils of ileum occupy lower part of infracolic compartment of abdominal cavity, and some extend into pelvis
large intestine
most of it arches around and encloses coils of jejunum and ileum
large intestine parts
cecum with vermiform appendix ascending colon transverse colon descending colon sigmoid colon rectum anal canal
cecum
blind-ended sac located in right iliac fossa, inferior to ileocecal junction
vermiform appendix
small, blind-ended tube, like a worm, that originates from posteromedial aspect of cecum
ascending colon
extends superiorly from ileocecal junction to inferior surface of right lobe of liver (in right hypochondriac region), where it bends to the left (right colic/hepatic flexure) to become continuous with transverse colon
transverse colon
crosses abdomen from right hypochondriac region to left hypochondriac region forming a wide U-shaped curve begins at right colic flexure when it reaches lower end of spleen, it bends inferiorly (left colic/splenic flexure) to become continuous with descending colon
descending colon
extends from left colic flexure to left iliac fossa
sigmoid colon
begins in left iliac fossa and forms a loop that terminates in pelvis (level of S3), where it becomes continuous with rectum
pancreas
exocrine and endocrine gland deeply located in abdomen (most of it lies posterior to peritoneal sac)
stretches across posterior abdominal wall from duodenum on the right to spleen on the left (epigastric and left hypochondriac regions)
parts: head, neck, body and tail (from right to left)
spleen
largest lymphoid organ of body; located in left hypochondriac region, between stomach and diaphragm
kidneys and ureters
kidneys are deeply placed organs (posterior to peritoneal sac), directly related to upper part of posterior abdominal wall, one on each side of vertebral column
each kidney gives rise to a ureter, which descends vertically on posterior abdominal wall and carries urine from kidney to urinary bladder
suprarenal glands
2 endocrine glands deeply located in abdomen, one on upper pole of each kidney
peritoneum
serous membrane that lines walls of abdominal and pelvic cavities and covers surface of abdominal and pelvic organs
peritoneum is more extensive than pleura and serous pericardium; it is related to many organs (not just one); it has a more complex arrangement
peritoneal layers
parietal peritoneum: lines walls of abdominal and pelvic cavities
visceral peritoneum: covers abdominal and pelvic organs
peritoneal cavity
potential space between parietal and visceral layers; contains small amount of serous fluid
in males it is a closed cavity
in females it communicates with outside via uterine tubes, uterus and vagina
intraperitoneal organ
organ that is almost totally covered with peritoneum ex.: stomach, jejunum, ileum, transverse colon, sigmoid colon, spleen
retroperitoneal organ
organ that is located posterior to peritoneal sac (between peritoneal sac and posterior abdominal wall); organ is only covered with peritoneum anteriorly
ex.: most of duodenum and pancreas, ascending colon, descending colon, kidneys, suprarenal glands, abdominal aorta, IVC
peritoneal ligaments
two-layered peritoneal fold that connects an organ (usually a solid organ) to abdominal wall or another organ
does not consist of dense fibrous connective tissue like ligaments associated with joints
falciform ligament
peritoneal fold that connects liver to anterior abdominal wall (above umbilicus)
coronary ligament
peritoneal fold that connects liver to diaphragm
splenorenal ligament
peritoneal fold that connects spleen to left kidney
gastrosplenic ligament
peritoneal fold that connects spleen to stomach
peritoneal folds
omentum (greater and lesser)
lesser omentum
two-layered peritoneal fold that connects lesser curvature of stomach and 1st part of duodenum to visceral (inferior) surface of liver
has 2 parts: hepatogastric and hepatoduodenal ligaments
hepatogastric ligament is thin
hepatoduodenal ligament forms right margin of lesser omentum and is thick because it contains ducts, blood vessels, lymph vessels and nerves traveling to and from liver
greater omentum
hangs down from greater curvature of stomach, like an “apron”, in front of loops of jejunum and ileum
contains a variable amount of fat; consists of 4 peritoneal layers
2 anterior layers descend from greater curvature of stomach, fold back on themselves and ascend (becoming 2 posterior layers) to attach to transverse colon; space between 2 anterior and 2 posterior layers is obliterated
mesentery
two-layered peritoneal fold that connects intestines to posterior abdominal wall
allows blood vessels, lymph vessels and nerves to reach intestines from posterior abdominal wall
parts of intestines that have mesentery are more mobile and are intraperitoneal
mesentery of small intestine (or just simply “the mesentery”): connects loops of jejunum and ileum to posterior abdominal wall
transverse mesocolon (mesentery of transverse colon): connects transverse colon to posterior abdominal wall
sigmoid mesocolon (mesentery of sigmoid colon): connects sigmoid colon to posterior abdominal and pelvic walls
more on peritoneal folds
mesenteries have a root: posterior border of mesentery attached to posterior abdominal wall
early in development, all parts of digestive tract are intraperitoneal and have a mesentery
with further development, some parts of digestive tract adhere to posterior abdominal wall, loose their mesentery and become retroperitoneal (more fixed in position); they are known as secondary retroperitoneal organs (ex.: most of duodenum, most of pancreas, ascending colon, descending colon)
omental bursa (lesser sac)
part of peritoneal cavity located posterior to lesser omentum and stomach
on the left it is closed by spleen, gastrosplenic ligament and splenorenal ligament
on the right it communicates with greater sac (remaining of peritoneal cavity) via omental (epiploic) foramen (a.k.a. opening of lesser sac, foramen of Winslow)
superior recess
upward extension of omental bursa, located between liver and diaphragm
inferior recess
downward extension of omental bursa between 2 anterior and 2 posterior layers of greater omentum (usually very short due to adherence of anterior and posterior layers of greater omentum)
omental (epiploic) foramen
opening of lesser sac
foramen of Winslow
anteriorly: right, free border of lesser omentum (hepatoduodenal ligament), within which are structures traveling to and from liver; 3 main structures: portal vein, proper hepatic artery and common bile duct
posteriorly: inferior vena cava
superiorly: caudate lobe of liver
inferiorly: 1st part of duodenum
1 median umbilical fold
formed by peritoneum that covers median umbilical ligament (fibrous cord that extends from apex of urinary bladder to umbilicus)
it is a remnant of allantois of embryo (when lumen of allantois obliterates in the embryo, it is called urachus; in the adult it is known as median umbilical ligament)
2 medial umbilical folds
formed by peritoneum that covers medial umbilical ligaments
fibrous cords that represent distal, obliterated parts of umbilical arteries
2 lateral umbilical folds
formed by peritoneum that covers inferior epigastric vessels
supracolic compartment
located above transverse colon and its mesentery; contains stomach, liver, gallbladder, spleen
infracolic compartment
located below transverse colon and its mesentery; contains most of the small and large intestines; divided into right and left infracolic spaces by mesentery of small intestine
paracolic gutters
grooves between lateral aspects of ascending and descending colon and abdominal wall that allow free communication between supracolic and infracolic compartments
peritoneal nerve supply
pain can be elicited by mechanical, chemical or thermal stimulation of parietal peritoneum, but usually only by stretching visceral peritoneum (ex.: over-distension of a hollow organ)
pain originating from parietal peritoneum is usually more intense and well localized
pain originating from visceral peritoneum is usually dull and poorly localized (referred pain)
parietal peritoneum innervation
peritoneum that covers central part of undersurface of diaphragm is innervated by phrenic nerves (pain referred to shoulder)
peritoneum that covers peripheral part of undersurface of diaphragm is innervated by lower 5 intercostal nerves and subcostal nerve
remaining of parietal peritoneum is innervated by lower 5 intercostal nerves, subcostal nerve and iliohypogastric and ilioinguinal nerves
visceral peritoneum innervation
visceral sensory fibers that travel with sympathetic and parasympathetic fibers that supply organs
