Lecture 7: The Pancreas

Question 1

What causes diabetes type II?

Answer 1

insulin resistance

Question 2

What is an acinus and what is its function?

Answer 2

the main pancreatic unit responsible for synthesizing and secreting enzymes and proenzymes.

Question 3

What is the function of glucagon?

Answer 3

It is secreted in response to a low glucose (during fasting); its action is to raise the blood glucose by stimulating glucose synthesis and glycogen breakdown

Question 4

Describe acinar cells

Answer 4

1. highly polarized
2. pyramidal in shape
3. basal nuclei
4. abundant RER
5. apical
6. contains membrane bound zymogen

Question 5

What percentage of an islet is comprised of A (alpha) cells?

Answer 5

5-30%

Question 6

What are the main cell types found in islets?

Answer 6

A (alpha), B (beta), and D (delta cells)

Question 7

What is the exocrine pancreas responsible for?

Answer 7

It produces the pancreatic juice, which is the most important of the digestive secretions

Question 8

What polypeptide do beta cells secrete?

Answer 8

insulin

Question 9

What are the function of D (delta) cells?

Answer 9

they secrete somatostatin in response to an increased blood glucose, which inhibits hormone relase from A and B cells.

Question 10

What causes acute pancreatitis?

Answer 10

proenzymes are activated early (in the pancreas) and they eat the tissue of the pancreas

Question 11

What is the role of a centroacinar cell?

Answer 11

they secretes water and elctrolytes and are the first cells of the intercalated ducts

Question 12

What type of hormones are secreted by the islet cells found in the endocrine pancreas?

Answer 12

polypeptides

Question 13

What is the pancreas?

Answer 13

A mixed endocrine and exocrine gland with acinar cells that form most of the gland’s volume

Question 14

What type of epithelium is found in an intercalated duct?

Answer 14

low cubodial or simple sqaumos

Question 15

Describe a centroacinar cell

Answer 15

pale, cubodial cells with elongated central nuclei and abundant mitchondria

Question 16

What are the main differences between an islet cell and an acinar cell?

Answer 16

islet cells are smaller and contain small membrane bound secretory granules

Question 17

How are islets arranged in the pancreas?

Answer 17

they are scattered throughout the exocrine pancrease with cells arranged in cords or clusters

Question 18

What are islet cells?

Answer 18

regions of the pancreas that contain the endocrine (hormone-producing) cells.

Question 19

What is the interlobular duct?

Answer 19

the location where the intralobular duct drains

Question 20

What type of epithelium lines an intralobular duct?

Answer 20

cubodial epithelium

Question 21

How much of the pancreatic volume is made up of islets?

Answer 21

about 1-2 %

Question 22

What is trypsinogen?

Answer 22

the inactive precursor of trypsin

Question 23

What type of cells are found in an intercalated duct?

Answer 23

pale, low cubodial centroacinar cells

Question 24

Where are acinar found?

Answer 24

in the exocrine pancreas

Question 25

What are **intralobular** ducts?

Answer 25

intercalated ducts that are joined together

Question 26

What are the proenzymes that are found in the pancreatic juice?

Answer 26

Zymogens

Question 27

Describe an islet cell

Answer 27

they are made up of parenchymal cells that are derived from the endoderm of the developing duodenum; Islets are very vascular

Question 28

What is the function of insulin?

Answer 28

it is released in response to an increased blood glucose (after eating) and acts to lower blood glucose by stimulating glucose uptake and glycogen synthesis in liver and muscle

Question 29

What color do alpha cells stain with aldehyde fuchsin?

Answer 29

brilliant red or orange

Question 30

What is the main function of the **intercalated** ducts of the pancreas?

Answer 30

they secrete large amounts of bicarbonate ions which neutralize acid from the stomach

Question 31

What is parenchyma?

Answer 31

the specific (functional) tissue of an organ as distinguished from the connective tissue or stroma

Question 32

Why are amylase, lipase, and trypsinogen significant to the pancrease?

Answer 32

They are enzymes of the pancreas that are capable of digesting the main components of ingested food(carbs, proteins, nucleic acids, lipids, and phospholipids). To prevent this, they are stored as inactive precursors of the pancreas.

Question 33

Where are the intralobular, interlobular, and intercalated ducts found in the pancreas?

Answer 33

in the exocrine part of the pancreas

Question 34

What causes Diabetes type I?

Answer 34

primary insulin deficiency

Question 35

What makes up the structure of the exocrine pancreas?

Answer 35

1. It is classified as compound tubuloacinar gland 2. It has sparse stroma 3. a thin capsule 4. and a delicate connective tissue septa that divide the gland into distinct lobules

Question 36

What polypeptide do A (alpha) cells secrete?

Answer 36

glucagon

Question 37

What type of stroma (connective tissue) is the endocrine pancreas made up of?

Answer 37

sparse reticular connective tissue

Question 38

What are pancreatic islets?

Answer 38

regions of the pancreas that contain the endocrine

Question 39

What makes up the pancreatic juice found in the exocrine pancreas?

Answer 39

enzymes and proenzymes that are activated in the intestine

Question 40

How many acinar cells are found in an acinus?

Answer 40

about 50

Question 41

What color do B (beta) cells stain with aldehyde fuchsin?

Answer 41

dark purple

Question 42

What is one difference between a parotid gland and a pancreatic gland?

Answer 42

they are no striated ducts or myoepithelial cells in the pancreas

Question 43

What is another name for a pancreatic islet?

Answer 43

Islets of Langerhans

Question 44

What percentage of an islet cell is comprised of B (beta) cells?

Answer 44

60-80 %

Question 45

What enzymes are found in the pancreatic juice?

Answer 45

amylase-carbohydrates, lipase-fats, trypsin-proteins,

Question 46

What is insulin responsible for?

Answer 46

keeping the sugar content of the blood at a constant level

Question 47

What is the endocrine pancreas responsible for?

Answer 47

produces several polypetide hormones such as insulin

Question 48

True or False The Endocrine pancreas acinar cells take up most of the space in the pancreas

Answer 48

FALSE The acinar cells are found in the exocrine pancreas, which takes up most of the space in the pancreas