Chapter 5-The pancreas (Penny)
Exocrine function
1. Amylase: digests carbohydrates and converts starch to sugar 2. Lipase: digests fats and converts fats to fatty acids and glycerol 3. Sodium bicarbonate: neutralizes stomach acid 4.Trypsin, chymotrypsin, and carboxypolypeptidase: digests proteins
The anteroposterior diameter of the main pancreatic duct should not exceed
2 mm
is the inflammation of the pancreas secondary to the leakage of pancreatic enzymes from the acinar cells into the parenchyma of the organ.
Acute pancreatitis
The pancreas can frequently be a neglected abdominal organ because of the challenge that it presents for the sonographer. ___________ and _________________ are two obstacles that the sonographer encounters when attempting to assess the pancreas using sound.
Adjacent bowel gas and body habitus
is typically elevated with gallstone pancreatitis.
Alanine aminotransferase (ALT)
appears to be more specific for diagnosing pancreatitis because hyperamylasemia can be associated with other abnormalities
Lipase
which is the most common congenital variant of pancreatic anatomy, results from abnormal fusion of the pancreatic ducts during embryologic development.
Pancreatic divisum
pancreatic pseudocyst
a cyst surrounded by fibrous tissue that consists of pancreatic enzymes that have leaked from the pancreas
von Hippel-Lindau disease
a hereditary disease that includes the development of cysts within the pancreas and other organs
insulinoma
a islet cell tumor found within the pancreas
Duct of Santorini
accessory duct to the pancreas
what part of the pancreas carries out the exocrine process?
acinar cells
The most common causes of acute pancreatitis are
alcohol abuse and biliary tract disease, such as choledocholithiasis
Whipple procedure
also known as a pancreaticoduodenectomy; a procedure in which the pancreas and duodenum are removed to treat conditions such as cancer
From the main pancreatic duct, the enzymes collect in the
ampulla of Vater
What vital digestive enzymes does the panc secrete?
amylase, lipase, and sodium bicarbonate
This abnormal duct arrangement can cause people to be be
asymptomatic, some may be prone to suffer from both chronic and acute pancreatitis
The opening of the sphincter of Oddi is triggered by __________________
cholecystokinin
The breakdown of the various food products into useful derivatives for the body ensues once the pancreatic enzymes and bile mix with
chyme in the proximal portion of the duodenum.
double duct sign
co-existing enlargement of the common bile duct and pancreatic duct
Cholecystokinin causes the simultaneous
contraction of the gallbladder and relaxation of the sphincter of Oddi
what does amylase do?
digests carbs
what does lipase do?
digests fats
To improve visualization of the pancreatic head, the sonographer can ask the patient to _______________________. The water, once in the C-loop of the duodenum, will provide a delineated view of the pancreatic head in most individuals.
drink a small cup of water
cholecystokinin is released by the
duodenum as a result of the presence of chyme.
With an annular pancreas, the most ventral part of the pancreas _______________________ and may lead to ___________. This anomaly is typically detected in the neonate with the use of radiography.
encases the duodenum and may consequently lead to duodenal obstruction
The involvement of the gland can be
focal or diffuse
The arterial blood supply to the head of the pancreas is via the
gastroduodenal artery
The normal measurement of the pancreatic head and body is between _____________, while the tail should measure between __________
head & body-2 and 3 cm tail-1 and 2 cm
Four parts of the pancreas
head, neck, body, tail
The pediatric pancreas may appear more ___________ because of the lack of fat surrounding the pancreas in younger patients
hypoechoic
The pancreatic margins may appear as
ill-defined with areas of fluid collections noted within and around the pancreas
acute pancreatitis
inflammation of the pancreas secondary to the leakage of pancreatic enzymes from the acinar cells into the parenchyma of the organ
The endocrine function of the pancreas is performed by the
islets of Langerhans
These clusters of tissue, which are dispersed like islands throughout the pancreas, are composed of alpha, beta, and delta cells
islets of Langerhans
Duct of Wirsung
main pancreatic duct
At the ampulla of Vater, the pancreatic digestive enzymes are mixed with bile from the liver and released into the duodenum through the
major sphincter, or sphincter of Oddi.
Acute pancreatitis may be classified as
mild, moderate, or severe
Higher _____________________ are associated with acute pancreatitis when the disease progresses and leads to severe necrosis and hemorrhage of the organ (termed hemorrhagic pancreatitis).
mortality rate
The pancreas is identified sonographically by its
neighboring vasculature
The __________ develops initially in the embryo from two separate parts that eventually fuse together to constitute its typical comma-shaped appearance.
pancreas
The two most common congenital anomalies of the pancreas are __________ and __________
pancreatic divisum and annular pancreas
Pancreatic divisum results in a shortened main
pancreatic duct (duct of Wirsung)
works to drain only the pancreatic head and not the entire pancreas
pancreatic duct (duct of Wirsung)
This abnormal duct arrangement causes a functional obstruction, disallowing proper pancreatic drainage and increasing the risk for
pancreatic inflammation secondary to the obstruction
the leakage of pancreatic enzymes can destroy the
pancreatic tissue and the tissues surrounding the pancreas
Chyme
partially digested food
This peripancreatic fluid collection may be referred to as
phlegmon
Milder cases of pancreatitis can
resolve spontaneously
In these situations (hemorrhagic pancreatitis), patients may suffer from
shock, ileus, and have a decreased hematocrit secondary to hemorrhage
Unfortunately, sonography is not always successful at diagnosing cases of acute pancreatitis because the pancreas may appear completely normal with mild disease. But it can provide useful information as to the __________ and ___________ of the gland and determine if any peripancreatic fluid collections exist.
size and echogenicity
Isles of Langerhans
small islands of tissue found within the pancreas that produce insulin and glucagon
The accessory duct (duct of Santorini), which is much
smaller than the main pancreatic duct
The body and tail of the pancreas receive their blood supply from the
splenic and superior mesenteric arteries
Color-flow Doppler imaging is helpful to differentiate the _______ from the ________________ because these two structures can have parallel paths within the body.
splenic artery; main pancreatic duct
These pancreatic enzymes drain from the pancreas into _______________ or ____________, which travels the length of the pancreas.
the main pancreatic duct, or duct of Wirsung
Pancreatic adenocarcinoma
the most common form of pancreatic malignancy; typically found within the head of the pancreas
Sphincter of Oddi
the muscle that controls the emptying of bile and pancreatic juices into the duodenum; also referred to as the hepatopancreatic sphincter
Phlegmon
the peripancreatic fluid collection that results from the inflammation of the pancreas
uncinate process
the posteromedial extension of the pancreatic head
choledocholithiasis
the presence of a gallstone or gallstones within the biliary tree
chronic pancreatitis
the recurring destruction of the pancreatic tissue that results in atrophy, fibrosis, scarring, and the development of calcification within the gland
The accessory duct (duct of Santorini), which is much smaller than the main pancreatic duct, is therefore forced to drain
the rest of the pancreas and empty a larger than normal amount of pancreatic juices through the minor sphincter
pancreaticoduodenectomy
the surgical procedure in which the head of the pancreas, the gallbladder, some of the bile ducts, and the proximal duodenum are removed because of a malignant pancreatic neoplasm; aka Whipple procedure
Zollinger-Ellison syndrome
the syndrome that includes an excessive secretion of acid by the stomach caused by the presence of a functional gastrinoma within the pancreas
jaundce
the yellow discoloration of the skin, mucous membranes and sclerae; found in presence of liver disease and or biliary obstruction
What other enzymes does the panc secrete?
trypsin, chymotrypsin, and carboxypolypeptidase
islet cell tumors
tumor found within the isles of Langerhans of the pancreas
In some individuals, there exists a posteromedial extension of the pancreatic head, referred to as the
uncinate process
autosomal dominant polycystic kidney disease
Inherited disease that results in the development of renal, liver, and pancreatic cysts late in life; also referred to as adult polycystic kidney disease
results from the maldevelopment of the two embryologic elements of the pancreas.
The annular pancreas
lesser sac
a peritoneal cavity space located between the stomach and pancreas where fluid can accumulate
Pancreatic divisum can lead to both
acute and chronic pancreatitis
Gastrinoma
an islet cell tumor found within the pancreas
Depending on the resolution of the ultrasound system, the normal main pancreatic duct may be noted during a routine sonographic examination. It will appear as an
anechoic tube, consisting of two parallel lines and an anechoic lumen
The sonographic analysis of the pancreas may include measurements of the various parts of the organ. The pancreas is typically measured in the ____________________ dimension in the transverse scan plane.
anteroposterior
hyperamylasemia
elevated amylase
The pancreas functions as an __________ and ___________ gland
endocrine and exocrine
endoscopic retrograde cholangiopancreatography
endoscopic procedure that utilizes fluoroscopy to evaluate the biliary tree and pancreas
Focal pancreatitis will lead to an
enlargement of the gland in a particular segment, most often in the head, appearing as a hypochoic region
Diffuse enlargement of the gland can also occur with pancreatitis, and with this manifestation the
entire pancreas will most likely become enlarged and hypoechoic
The pancreas is both an ______________ and an_____________________________
exocrine gland (uses ducts to transport digestive juices) and endocrine gland (releases hormone directly into the bloodstream).
Primary function of the pancreas?
exocrine gland that aids in digestion
In the transverse plane, two round anechoic structures may be noted within the pancreatic head. The anterior structure is the _________________________, and the more posterior structure is the _____________________
gastroduodenal artery; common bile duct
Insulin stimulates the body to use up
glucagon to produce energy
Glucagon promotes the release of ________________________, which in turn __________________
glucose by the liver; increases blood sugar levels
The normal echogenicity of the pancreas is
greater than that of the liver, and equal to, or greater than, that of the spleen in the adult.
The islets of Langerhans produce vital hormones, including _______ and ________, which are released directly into the bloodstream
insulin and glucagon
To better visualize the pancreatic tail area, the sonographer can scan through the
left kidney and spleen while the patient is in the right lateral decubitus position.
Additionally, the __________________________ position may help improve visualization of the pancreatic head.
left lateral decubitus
Amylase levels will rise first, and within 72 hours an accompanying rise in _______ should occur.
lipase
__________ is located within the epigastrium between the C-loop of the duodenum and the splenic hilum.
pancreas
Other causes of acute pancreatitis include
post endoscopic retrograde cholangeopancreatography and trauma
Although some of the pancreatic head may be covered by peritoneum, the pancreas is considered to be a
retroperitoneal organ
Venous drainage is achieved by means of the
splenic vein, superior mesenteric vein, inferior mesenteric vein, and portal vein
Patients suffering from acute pancreatitis may find relief from symptoms in certain positions. For example, the _______ position is often most painful, while ________________ may temporarily relieve pain
supine; sitting or leaning forward
acinar cells
the cells of the pancreas that carry out the exocrine function and therefore produce amylase, lipase, and sodium bicarbonate
Courvoisier gallbladder
the clinical detection of an enlarged, palpable gallbladder caused by a biliary obstruction in the area of the pancreatic head
An accessory duct, _______________________, which is typically a branch of the main pancreatic duct, has a separate minor sphincter into the duodenum.
the duct of Santorini
Ampulla of Vater
the merging point of the pancreatic duct and common bile duct just before the sphincter of Oddi