The pancreas (Week 7)

Question 1

what is the pancreas

Answer 1

an accessory organ of digestion with both endocrine and exocrine functions

Question 2

what does the exocrine release

Answer 2

bicarbonate and pancreatic lipases and proteases

Question 3

what does the endocrine release

Answer 3

glucagon and insulin

Question 4

where is the pancreas found

Answer 4

found retroperitoneally at about level L1/L2

Question 5

acinar cells function

Answer 5

synthesize and secrete digestive enzymes

Question 6

islet of langerhans function

Answer 6

regulation of blood glucose levels

Question 7

alpha cells produce what

Answer 7

glucagon

Question 8

beta cells produce what

Answer 8

insulin

Question 9

delta cells produce what

Answer 9

somatostain

Question 10

f cells produce what

Answer 10

pancreatic polypeptide

Question 11

in the synthesis of insulin what is the first stage

Answer 11

transcription. Insulin gene found in DNA of beta cell. mRNA forms

Question 12

in the synthesis of insulin what is the second stage

Answer 12

translation. mRNA enters cytoplasm, ribosomes read mRNA and preproinsulin is formed.

Question 13

in the synthesis of insulin what is the third stage

Answer 13

preproinsulin. 3 parts. signal sequence, insulin chain, connecting pepetide (C peptide) signal leads preproinsulin to ER

Question 14

in the synthesis of insulin what is the fourth stage

Answer 14

processing of ER. Signal sequence removed. Proinsulin formed

Question 15

in the synthesis of insulin what is the fifth stage

Answer 15

formation of insulin and C peptide. proinsulin now in golgi. proinsulin cleaved to mature insulin and C-peptide

Question 16

insulin release

Answer 16

fasting blood glucose = 4-5 mmol l-1
post prandial blood glucose = up to 10 mmol l-1

Question 17

what stimulates the release of insulin

Answer 17

blood glucose concentration
amino acids
- leucine, isoleucine, alanine and arginine

incretins
- GIP and GLP-1
Glucagon
hyperkalaemia
Vagal nerve stimulation

Question 18

what inhibits the release of insulin

Answer 18

Norepinephrine and epinephrine
somatostatin

Question 19

stimulation of alpha cells in release of glucagon

Answer 19

rising concentrations of amino acids
- arginine and alanine

GIP
Hypoglycemia
epinephrine

Question 20

inhibition of alpha cells in the release of glucagon

Answer 20

amylin, insulin and somatostatin
insulin
GLP-1
Hyperglycaemia

Question 21

what is glycogenolysis

Answer 21

Glycogenolysis is the biochemical process by which glycogen, a polysaccharide (complex sugar) that serves as a storage form of glucose, is broken down into individual glucose molecules.

Question 22

what is the effect of hypoglycaemia

Answer 22

blood glucose levels <4 mmol l-1
low blood glucose deprives neurones of source of fuel
- neuroglycopenia
- counter-regulatory responses

can be side effect of management of Diabetes Mellitus
-whipple triad

Question 23

what is the effect of hyperglycemia

Answer 23

blood glucose level > mmol l-1 before eating

chronic state can lead to altered nutrient metabolism
- glycated proteins
- osmotic diuresis

Question 24

what is type 1 diabetes

Answer 24

autoimmune disease b cell destruction
absolute insulin deficiency

Question 25

what is type 2 diabetes

Answer 25

progressive loss of b cells insulin secretion
insulin resistance

Question 26

what is gestational diabetes mellitus

Answer 26

diabetes diagnosed in 2nd and 3rd trimester of pregnancy
no clear over diabetes prior to gestation

Question 27

T1DM- aetiology and common features

Answer 27

Genetic predisposition (polygenic)
Environmental tigger (viral infection)
autoimmune response - destruction of pancreatic B cell

most common in childhood and adolescence

Question 28

T2DM - aetiology and common features

Answer 28

genetic and epigentic factors
environmental factors (sedentary lifestyle, obesity)
inulin resistance and dysfunction of pancreatic B cells