The Pancreas Flashcards
why can the pancreas be described as a dual purpose gland
it has both hormonal and digestive functions
is the pancreas exocrine or endocrine in function
both
describe the endocrine portion of the pancreas
islets of langerhans
what are the islets of langerhans responsible for
secretion of hormones, insulin, glucagon and somatostatin
which portion of the pancreas is responsible for secretions passing to the bloodstream
endocrine
which makes up more of the pancreas; exocrine or endocrine
exocrine, at 99%
what does the exocrine portion of the pancreas contain
digestive enzymes and bicarbonate ions
what is insulin
the hormone responsible for promoting glucose absorption from the blood into the liver, skeletal muscle and fat cells, and enables conversion into its storage form, glycogen
what is glucagon
the hormone that converts stored glycogen into glucose for release into the blood stream when levels are low
what is somatostatin
the hormone that reduces acid secretion and helps to slow down the digestive process, although it has a variety of other functions in the body
what do the digestive enxzymes found in the exocrine portion of the pancreas do
they break down carbohydrates, proteins and fats
what is the pancreas acinus
cluster of cells found in the pancreas that produce digestive enzymes
what are the digestive enzymes produced in the exocrine pancreas
amylase
lipase
trypsin
chymotrypsin
nucleases
how is bicarbonate produced in the exocrine pancreas
comes from the ducts of the pancreas
what are the functions of the bicarbonate ions found in the exocrine pancreas
neutralising gastric acid so there is an optimum ph
what does amylase do
breaks down starch into sugars
what does lipase do
breaks down fats into monoglyceride and fatty acids
what is trypsin involved in
breakdown of fats into monoglyceride and fatty acids
how is trypsin secreted
in its inactive form, trypsinogen
what does trypsin do
breaks down or hydrlyses proteins
what does chymotrypsin arise from
inactive chymotryupsinogen
what does chymotrypsin do
breaks down proteins and polypeptides
what do nucleases break down
nucleotides
what are the regions of the pancreas
head
uncinate process
neck
body
tail
describe the head of the pancreas
this is the widest part of the pancreas and lies within the c shaped curve created by the duodenum
it is connected to the duodenum by connective tissue
which section of the pancreas is the widest
the head of the pancreas
which region of the pancreas is found within the c curvature of the duodenum
the head of the pancreas
how is the head of the pancreas attached to the duodenum
connective tissue
describe the uncinate process of the pancreas
this is a projection arising from the lower part of the head that extends medially to lie beneath the body of the pancreas
lies posterior to the superior mesenteric vessels
what is the neck of the pancreas
this is the region of the pancreas found between the head and body regions. overlies the superior mesenteric vessels, forming a groove in its posterior aspect
which region of the pancreas extends medially to lie beneath the body of the pancreas
the uncinate process
which region of the pancreas lies posterior to the superior mesenteric vessels
the uncinate process
which region of the pancreas is located between the head and body
the neck
which region of the pancreas overlies the superior mesenteric vessels, forming a groove in its posterior aspect
the neck
how is the body of the pancreas located
centrally, crossing the midline of the human body to lie behind the stomach and to the left of the superior mesenteric vessels
which region of the pancreas is intraperitoneal
the tail
describe the location of the tail of the pancreas
left end of the pancreas, lies within close proximity to the hilum of the spleen. contained within the splenorenal ligament with the splenic vessels
what is the major duodenal papilla surrounded by
sphincter of oddi
what is the major duodenal papilla
rounded projection at the opening of the common bile duct and the pancreatic duct
how is the minor duodenal papilla located in relation to the major papilla
2cm proximal to it
how common is a minor duodenal papilla
occurs in 10% of people
what is the minor duodenal papilla
the opening of the accessory pancreatic duct
what are the three forms of the islets of langerhans
alpha
beta
delta
what do alpha islets of langerhans secrete
glucagon
what do beta islets of langerhans secrete
insulin
what do delta islets of langerhans secrete
somatostatin
how many islets of langerhans are alpha
15%
how many islets of langerhans are beta
80%
how many islets of langerhans are delta
5%
what composition of the pancreas do islets of langerhans take up
1%
describe the exocrine pancreas
- lobulated serous glands
- produce a number of enzymes essential for digestion
- acini connected by short intercalated ducts
- acini link to intralobular ducts which ultimately drain to the pancreatic duct
- centroacinar cells are extenstions of the intercalated ducts into each pancreatic acinus
- typically secretes bicarbonate and mucin
what are acini
clusters of acinar cells
how are acini connected
intercalated ducts
what join together to drain the pancreatic duct
acini link to interlobular ducts
what are centroacinar cells
spindle shaped extensions of intercalated ducts
what is cystic fibrosisq
autosomal recessive inherited condition that mostly affects the lungs, and is an issue with the exocrine portion of the pancreas.
leads to abnormal thick secretions, damaging the lungs, liver and pancreas
what does cystic fibrosis cause
abnormal thick secretions that damage the lungs, liver and pancreas and salivary glands.
destruction of the exocrine pancreas leading to reduced digestive function, malabsorption and steorrhoea.
when do the symptoms of cystic fibrosis begin
childhood
how does cystic fibrosis cause malabsorption
destruction of the pancreas and the ability to secrete digestive enzymes
how does cystic fibrosis lead to steorrhoea
there is no breakdown of fats so stools become fatty
which organs are affected by cystic fibrosis
- sinuses
- lungs
- skin
- liver
- pancreas
- intestines
- reproductive organs
how does cystic fiboris affect sinuses
infection
how does cystic fiboris affect lungs
build up of thick, sticky mucous. can lead to bacterial infection and widened airways
how does cystic fiboris affect skin
sweat glands can produce salty sweat
how does cystic fiboris affect the liver
blocked biliary ducts
how does cystic fiboris affect the pancreas
blocked pancreatic ducts
how does cystic fibrosis affect the intestines
cannot fully absorb nutrients
how can cystic fibrosis affect fingers and toes
leads to clubbing, where there is increased convexity of the nail and thickening of the digits distally
describe pancreatic cancer
affects the head of the pancreas and can lead to loss of appetite or weight loss. patients can feel tired or lethargic. can also lead to abdominal pain.
biliary obstruction blocks the bile and pancreas secretions and can lead to jaundice due to build up of bilirubin that hasnt been excreted.
pale stools
can spread to other sites like the liver
what is jaundice
yellowing of the skin and sclera