Diabetes Part 1.PP slides 1-43 Flashcards Preview

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Flashcards in Diabetes Part 1.PP slides 1-43 Deck (49)
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1

Where is the pancreas? 

  • The pancreas located deep to the stomach

  • Stretches across the abdomen with

    –Head adjacent to the duodenum

    –Tail adjacent to the spleen

2

Another picture of the pancreas

3

What two major types of tissues make up the pancreas and what do they secrete?

  1. Acini- secrete digestive juices into the duodenum (exocrine)
  2. Islets of Langerhans- secrete insulin and glucagon directly into the blood (endocrine)

4

4 types of cells contained in the Islets

How are they distinguished from one another? 

  1. α-

  2. β-

  3. δ-

  4. PP

 –Types are distinguished from one another by their morphological and staining characteristics

5

3 fun facts about β-cells

(not really fun, but let's pretend) 

  1. Constituting about 60% of all the cells of the islets

  2. Lie mainly in the middle of each islet

  3. Secrete insulin and amylin (inhibits insulin secretion, any other effects unknown)

6

How many α-cells are in the Islets roughly? What do they secrete?  

  • about 25% of the total

  • Secrete glucagon

7

How many δ-cells are in the Islets roughly? What do they secrete?  

  • About 10% of the total

  • Secrete somatostatin

8

How many PP cells are in the Islets roughly? What do they secrete?  

  • Very few in number

  • Secretes a hormone of uncertain function called pancreatic polypeptide

9

What does PP stand for in PP cells?

Pancreatic Polypeptide

10

Point about communication among cells in pancreas

The close interrelations among these cell types allow cell-to-cell communication and direct control of secretion of some of the hormones by the other hormone

11

What does insulin inhibit?

glucagon secretion

12

What does amylin inhibit?

insulin secretion

13

What does somatostatin inhibit?

the secretion of both insulin and glucagon

14

What is Diabetes Mellitus?

Chronic disorder caused by either deficient insulin, or defective insulin action

–Hyperglycemia

–Disruption of metabolism of carbohydrates, fats, and proteins

15

Diabetes Mellitus is the leading cause of what 3 things?

  1. ESRD (end stage renal disease)

  2. blindness

  3. non-traumatic amputation of LE

*has cascading effect on other diseases

16

What are the effects of insulin on the metabolism? 

  1. Increase carbohydrates storage as glycogen mainly in the liver and muscles
  2. Increase amino acid uptake and protein synthesis
  3. Increase fatty acid storage in adipose tissue

17

Basic explanation of how insulin is involed in Type 1 and 2 Diabetes

•Type I DM – little or no insulin produced

•Type 2 – defective insulin and/or impaired cell receptor binding of insulin

18

What happens with carbohydrate metabolism with glucose uptake in the muscle?

–Activity – increase membrane permeability to glucose during moderate or heavy exercise 

–Carbohydrate consumption - Insulin can increase the rate of transport of glucose into the resting muscle cell by at least 15-fold

19

What is the purpose of GLUT1 transporters in the brain?

Brain has GLUT1 transporters so glucose uptake in brain not directly insulin dependent

20

True or False: Critical blood glucose level for normal brain function is > 20-50 mg/dl  which is relatively high.

False

It is relative low

21

What can happen to the brain if a person becomes too hyperglycemic or hypoglycemic? 

Hypoglycemic shock with fainting, seizures, and even coma

Hyperglycemia shows a progressive loss of consciousness leading to coma

*Both have the capcity to slowly shut the brain down

22

3 major insulin effects that lead to fat storage in adipose tissue

  1. Increases the utilization of glucose will decrease the utilization of fat, thus functioning as a fat sparer (allows us to use readily availible glucose)

  2. Promotion of fatty acid synthesis

  3. Increase  uptake of glucose by adipose cells and conversion into fatty acids as just discussed

23

Relationship between insulin and plasma cholesterol (3)

 

 

(Include: How much does plasma lipoproteins change?)

  • Insulin deficiency promotes increase plasma cholesterol and phospholipid synthesis from fatty acids in the liver.

  • Occasionally the plasma lipoproteins increase as much as 3X in the absence of insulin

  • This high lipid concentration-especially the high concentration of cholesterol-promotes the development of atherosclerosis in people with deficient insulin action

24

What effect does does ketoacidosis have on a diabetics breath?

It gives a fruity breath smell

25

Relationship between insulin and ketoacidosis (4)

  • Insulin deficiency promotes ketoacidosis

  • When fats are used for metabolism b-oxidation of the fatty acids produces acetyl-CoA

  • Excessive acetyl-CoA forms ketone bodies and decrease pH – ketoacidosis

  • Ketoacidosis, if severe, can lead to coma and death

26

Example of a ketogenic diet

Atkins

High in fat and protein

Low in Carbs

*Research being done on effects of ketogenic diet and kids with autism and seizures

27

Relationship between increased protein synthesis and insulin storage (5)

  • Stimulates transport of many amino acids into the cells
  • Increase the translation of messenger RNA, thus forming new proteins
  • Increase the rate of transcription of selected DNA genetic sequences in the cell nuclei, thus forming increased quantities of RNA and still more protein synthesis
  • Maintains high levels of amino acids by inhibiting deamination & decreased rate of gluconeogenesis
  • Inhibits the catabolism of proteins by cellular lysosomes 

28

What is normal for blood glucose? (3)

–Usually between 70 and 120 mg/dl of blood in the fasting person each morning before breakfast (some references 70-100)

–Increase to 120 to 140 mg/100 ml during the first hour or so after a meal

–Blood glucose concentration back to fasting level usually within 2 hours after the last absorption of carbohydrates

*may have a variation of 10mg/dl 

29

How does a lack of insulin affect protein metabolism? (3)

  • Increase protein catabolism and decreased rate of protein synthesis 

  • Increase [amino acid] in blood due to amino acid dumping by tissue

  • Protein wasting leading to extreme weakness as well as many deranged functions of the organs can result from insulin deficiencies

30

Factors and conditions that increase Insulin secretion (3)

•Insulin resistance

•If cell receptors become damaged, glucose cannot be absorbed from the bloodstream, prompting ↑ insulin production to overcome the resistance

•Obesity – “belly fat” hormones (metabolic syndrome causing insulin resistance, ↑BP, ↑lipids, cardiovascular disease)