Largest gland in the body
After the skin, the largest single organ
2.5% of adult body weight
Except for fat, all nutrients absorbed from the digestive tract are
initially conveyed to the liver by the portal venous system.
In addition to its many metabolic activities, the liver stores glycogen
and secretes bile, a yellow-brown or green fluid that aids in the
emulsification of fat.
Bile passes from the liver via biliary ducts—right and left hepatic
ducts—join to form common hepatic duct, which unites with the
cystic duct to form the (common) bile duct.
The liver produces bile continuously; however, between meals it
accumulates and is stored in the gallbladder, which also concentrates
the bile by absorbing water and salts.
When food arrives in the duodenum, the gallbladder sends
concentrated bile through the biliary ducts to the duodenum.
The normal liver lies on the right side and crosses the midline toward
the left nipple.
Liver occupies most of the right hypochondrium and upper epigastrium
and extends into the left hypochondrium.
Liver has
A convex diaphragmatic surface (anterior, superior, and some
posterior)
A relatively flat or even concave visceral surface (posteroinferior),
separated anteriorly by its sharp inferior border that follows the
right costal margin.
The diaphragmatic surface of the liver is covered with visceral
peritoneum, except posteriorly in the bare area of the liver, where it
lies in direct contact with the diaphragm.
Externally, liver is divided into 2 anatomical lobes & 2 accessory lobes by
the reflections of peritoneum from its surface, the fissures formed in
relation to those reflections and the vessels serving the liver and the
gallbladder.
These superficial “lobes” are not true lobes as the term is generally used
in relation to glands and are only secondarily related to the liver's
internal architecture.
The essentially midline plane defined by the attachment of the falciform
ligament and the left sagittal fissure separates a large right lobe from a
much smaller left.
On the visceral surface, the right and left sagittal fissures course on each
side of—and the transverse porta hepatis separates:
2 accessory lobes (parts of the anatomic right lobe):
Quadrate lobe anteriorly and inferiorly
Caudate lobe posteriorly and superiorly.
Lies in fossa for the gallbladder on the visceral surface of the liver.
This shallow fossa @ junction of right & left liver.
Relationship of gallbladder to duodenum is so intimate that the
superior part of the duodenum is usually stained with bile in the
cadaver.
In its natural position the body of the gallbladder lies anterior to the
superior part of the duodenum, its neck and cystic duct are
immediately superior to the duodenum.
Convey bile from the liver to the duodenum.
Bile is produced continuously by the liver and stored, concentrated in
the gallbladder, which releases it intermittently when fat enters the
duodenum.
Bile emulsifies the fat so that it can be absorbed in the distal
intestine.
The bile duct (formerly called the common bile duct) forms by the union
of the cystic duct and common hepatic duct.
The bile duct descends posterior to the superior part of the duodenum
and lies in a groove on the posterior surface of the head of the
pancreas.
PANCREAS
Elongated, accessory digestive gland that lies retroperitoneally,
overlying and transversely on the posterior abdominal wall.
Lies posterior to the stomach between the duodenum on the right and
the spleen on the left.
The pancreas produces:
 Exocrine secretion (pancreatic juice from the acinar cells) enters the
duodenum through the main and accessory pancreatic ducts.
 Endocrine secretions (glucagon and insulin from the pancreatic islets
[of Langerhans]) enter the blood.
Pancreas is divided into 4 parts:
Head
Neck
Body
Tail
The main pancreatic duct begins in the tail of the pancreas.
Main pancreatic duct+ bile duct= hepatopancreatic ampulla (of Vater)
opens into the duodenum at the summit of
Major duodenal papilla
Ovoid, usually purplish, pulpy mass about the size and shape of
one's fist.
Relatively delicate and considered the most vulnerable abdominal
organ.
Located in the superolateral part of the left upper quadrant (LUQ) or
hypochondrium of the abdomen where it enjoys protection of the
inferior thoracic cage.
As the largest of the lymphatic organs, it participates in the body's
defense system as a site of lymphocyte (white blood cell) proliferation
and of immune surveillance and response. To accommodate these
functions, the spleen is a soft, vascular (sinusoidal) mass with a
relatively delicate fibroelastic capsule.
The diaphragmatic surface of the spleen is convexly curved to fit the
concavity of the diaphragm and curved bodies of the adjacent ribs.
Continuous, slippery transparent serous membrane.
Lines the abdominopelvic cavity and invests the viscera.
Consists of two continuous layers:
Parietal peritoneum
lines the internal surface of the abdominopelvic wall
Visceral peritoneum
invests viscera such as the stomach and intestines.
A potential space of capillary thinness between the parietal and
visceral layers of peritoneum
Within the abdominal cavity, and continues inferiorly into the pelvic
cavity.
Contains a thin film of peritoneal fluid, which is composed of water,
electrolytes, and other substances derived from interstitial fluid in
adjacent tissues.
Formed in relation to the relocation of the testis during fetal
development.
An oblique passage approximately 4 cm long directed inferomedially
through the inferior part of the anterolateral abdominal wall
Lies parallel and superior to the medial half of the inguinal ligament.
Main occupant of the inguinal canal
Spermatic cord in males
Round ligament of the uterus in females
Portal vein
Final common pathway for the transport of venous blood from the
spleen, pancreas, gallbladder, and the abdominal part of the
gastrointestinal tract.
Formed by the union of splenic vein & superior mesenteric vein
posterior to the neck of the pancreas.
Venous drainage of the spleen, pancreas, gallbladder, and the
abdominal part of the gastrointestinal tract, except for the inferior
part of the rectum, is through the portal system of veins, which deliver
blood from these structures to the liver.
Once blood passes through the hepatic sinusoids, it passes through
progressively larger veins until it enters the hepatic veins, which return
the venous blood to the inferior vena cava just inferior to the
diaphragm.
A rich blood supply to support its digestive activities.
Arterial blood supplied mainly by
Coeliac artery to the stomach, pancreas, spleen and liver
Mesenteric arteries to the intestines.
Venous blood drains from the stomach, pancreas and spleen via the
hepatic portalvein into the liver, where the products of digestion
undergo further processing and detoxification.
Blood from oesophagus and rectum does not go through the liver but
drains directly into the venous system.
There are two types of nerve supply to the GI tract. The enteric
system, found within the walls of the GI tract, is sometimes
known as the 'gut brain' and controls movement and secretion
within the gut. Nerves from the autonomic nervous system also
supply the GI tract.
Sympathetic system
reduce blood flow to the gut
decrease secretions, motility and contractions,
Parasympathetic system
Increase in motility and secretion within the tract and relaxation of the
gut sphincters.
The vagus nerve (Xth cranial) supplies the oesophagus, stomach,
pancreas, bile duct, small intestine and upper colon.
Abdominal cavity
Forms the superior and major part of the abdominopelvic cavity.
Has no floor of its own because it is continuous with the pelvic cavity.
Plane of the pelvic inlet (superior pelvic aperture) arbitrarily, but not
physically, separates the abdominal and the pelvic cavities.
is the location of most digestive organs, parts of the urogenital
system (kidneys and most of the ureters), and the spleen.
More superiorly placed abdominal organs (spleen, liver, part of the
kidneys, and stomach) are protected by the thoracic cage.
G
Greater pelvis (expanded part of the pelvis superior to the pelvic inlet)
supports and partly protects the lower abdominal viscera (part of the
ileum, cecum, and sigmoid colon).
9 regions of the abdominal cavity
Regions are delineated by 4 planes:
2 sagittal (vertical)
2 transverse (horizontal) planes
2 sagittal planes
Midclavicular (approximately 9 cm from the midline)
Midinguinal points
midpoints of the lines joining the anterior superior iliac spine (ASIS)
and the superior edge of the pubic symphysis on each side.
Two vertical lines
Subcostal plane
inferior border of the
10th costal cartilage
Transtubercular plane
iliac tubercles (5 cm
posterior to ASIS on
each side) and body of
L5)
Muscles of the Anterolateral Abdominal Wall
There are 5 (bilaterally paired) muscles in the anterolateral
abdominal wall:
3 flat muscles & 2 vertical muscles
3 flat muscles
External oblique
Internal oblique
Transversus abdominis
2 vertical
large Rectus abdominis
small Pyramidalis
The aponeuroses interweave
with their fellows of the
opposite side, forming a midline
raphe (G. rhaphe, suture,
seam), linea alba (L. white line),
which extends from the xiphoid
process to the pubic symphysis.