GHM L7

Question 1

Describe the location of the pancreas

Answer 1

Abdominal, behind stomach
15 cm long

Question 2

Describe the anatomy of the pancreas

Answer 2

3 parts:

Head (points into the inner curvature of the duodenum)
Body (longest part, the main pancreatic duct and the accessory pancreatic duct run through the body)
Tail - adjascent to spleen

Pancreas opens into the duodenum

Has lobules

Question 3

How does the hepatopancreatic ampulla form?

Answer 3

When common bile duct joins with main pancreatic duct

Question 4

State the secretory cells in the pancreas

Answer 4

1. Duct cells
2. Acinar cells

Question 5

What is the function of acinar cells ?

Answer 5

1. Secrete digestive enzymes

Question 6

What is the function of duct cells?

Answer 6

Secrete bicarbonates

Question 7

What does pancreatic juice consist of?

Answer 7

Digestive enzymes (proteases, lipases, nucleases, amylases) and bicarbonates (HCO3-)

Question 8

State which hormones control the formation of pancreatic juice

Answer 8

CCK - stimulates acinar cells to release digestive enzymes
Secretins - stimulate duct cells to release bicarbonates

Question 9

State what stimulates the release of CCK?

Answer 9

TG, FA, AA

Question 10

State what stimulates the release of secretin?

Answer 10

acidic chyme

Question 11

What are the 3 types of cells present in the islet of langerhan in the pancreas consist of?

Answer 11

1. Alpha cells - (glucagon producing)
2. Beta cells - (insulin producing)
3. Acinar cells - (exocrine)

Question 12

State the function of bicarobonates in pancreatic juice

Answer 12

Neutralise acidic chyme
Balance the acid from the stomach

Question 13

Pancreatic proteases

Answer 13

Pancreatic proteases are released as zymogens

Zymogens are then activated in the small intestine

For example, trysinogen is activated into trypsin by enteropeptidase

Question 14

Amylases, nucleases, lipases

Answer 14

Do not need to be activated, they are secreted inrto duodenum in active form

They just need

Ions / bile

Question 15

State the endocrine function of the pancreas

Answer 15

Occurs in islet of langerhans

• Alpha cells - secrete glucagon
  -Beta cells - secrete insulin
  -Delta cells - somatostatin
• PP cells - secrete pancreatic polypeptide - regulation of gastric secretions

Question 16

State the exocrine function of the pancreas

Answer 16

Release of fluid (pancreatic juice) via pancreatic ducts onto epithelial surface of duodenum

Digestive enzymes
-Proteases
-Lipases
-Nuclueases
-Carboxypeptidases

Bicarbonates (HCO3-)

Question 17

What is the function of insulin?

Answer 17

Blood glucose homeostasis (reducing blood glucose levels)

Question 18

How is insulin secreted ?

Answer 18

Beta cells, islets of langerhans, to TARGET ORGANS

• Muscle / skeletal tissue
  -Liver
  -Adipose tissue

Question 19

How does insulin act on its target organs?

Answer 19

Muscle Tissue:

Increases gluocse uptake from blood - converts glucose to glygen - glycogenesis
Increase amino acid uptake from blood - to form protein (protein synthesis)
Decreased glycogen + protein breakdown

Liver

Increased glucose uptake from blood to produce glycogen - glycogenesis
Decreased rate of glycogenolysis - glycogen to glucose
Increased TAG synthesis
Decreased ketone formation
Decreased protein + TAG breakdown

Adipose tissue

Increased uptake of glucose from blood, leading to fat production (increased TAG synthesis, decreased TAG breakdown)

Question 20

State the function of glucagon

Answer 20

Blood glucose homeostasis - increases glucose conc

Question 21

How is glucagon secreted?

Answer 21

Alpha cells in islets of Langerhans
To target hormone - Liver

Question 22

How does glucagon act on its target hormone?

Answer 22

Liver:

Increases glycogenolysis (glycogen - glucose), increase conc of enzyme glycogen phosphorylase

Increases fatty acid uptake and glycerol uptake to form glucose

Decreases glycognesis - therefore, decreases conc of enzyme glycogen synthethase

Question 23

Why is blood glucose level controlled in a counter regulatory manner?

Answer 23

Because the actions of insulin and glucagon oppose each other

Question 24

Explain the counter-regulatory control of blood glucose homeostasis

Answer 24

Glucagon release is inhibited when insulin is released / presence of insulin

Glucagon is released when no insulin
-Starvation
-Exercise
-Stress

Question 25

Why is glucagon released during times of starvation exercise/starvation/stress?

Answer 25

In these times, low blood glucose levels Glucagon is secreted by alpha cells in the islets of Langerhans to its target organ - liver It mobilises glucose stores (glycogen) and provides glucose to muscles during exercise

Question 26

Describe how insulin is controlled by a negative feedback mechanism

Answer 26

Insulin is controlled by a negative feedback mechanism in response to low levels of glucose upon insulin secretion Diagram L7

Question 27

Describe how glucagon is controlled by negative feedback

Answer 27

Glucagon is controlled by negative feedbackl in response to high glucose levels upon glucagon secretion Diagram L7

Question 28

Explain the role of the nervous system of blood glucose levels

Answer 28

Parasympathetic nervous system innervates the islets of Langerhans -neurotransmitter - ACh -Stimulates insulin secretion Sympathetic nervous system innervates islets of Langerhans -Neurotransmitter - Noradrenaline -Stimulates glucagon release -Inhibits insulin release

Question 29

State two other hormones involved in glucose regulation

Answer 29

Glucocorticoids Somatostatins

Question 30

State the function of glucocorticoids

Answer 30

Cortisol - secreted by adrenal cortex Function: Increases gluconeogensis Decreases glucose utilziation by cells Increases release of fatty acids by adipose cells

Question 31

State the function of somatostatins

Answer 31

Decreases insulin and glucagon secretion

Question 32

What is diabetes mellitus?

Answer 32

1. Decreased sensitivity of cells to insulin 2. Insulin deficiency 3. Complete lack of insulin

Question 33

What is the cause of Type 1 diabetes?

Answer 33

IDDM - insulin dependent diabetes mellitus

Question 34

State the cause of gestational diabetes What other complications can it lead to?

Answer 34

Pregnant women, No prior diabetes Natural - interference with insulin receptors Persistant hypergylcemia - increased risk of big baby syndrome macrosomia - miscarriage Recovery usually follows delivery

Question 35

Why must insulin be administered by injection and not orally?

Answer 35

Insulin is a peptide hormone and therefore, can be destroyed by gastric acid in the stomach

Question 36

Why may insulin treatment itself be hazardous?

Answer 36

Hypoglycemoa

Question 37

State pathologies related to the pancreas

Answer 37

1. Pancreatic cancer 2. Acute / chronic pancreatitis 3. Cystic fibrosis 4. Exocrine pancreatic insufficiency

Question 38

State a common cause of acute pancreatitis

Answer 38

Gall stones (and high triglyceride levels)

Question 39

State a common cause of chronic pancreatitis

Answer 39

Alcohol (and high triglyceride levels)

Question 40

State the two types of pancreatic cancers

Answer 40

Exocrine cancer Neuroendocrine cancer

Question 41

State a cause of pancreatic exocrine cancer

Answer 41

Acinar cell carcinoma Leads to increase in production of digestive enzymes

Question 42

State a cause of pancreatic neuroendocrine cancer

Answer 42

Pancreatic neuroendocrine tumours (PaNETP) - benign / malignant Can be functioning / non-functioning Functioning - produce hormones: insulin (insulinomas), gastrone (gastrinomas),

Question 43

Why can pancreatic neuroendocrine cancer be dangerous?

Answer 43

Often has late diagnosis