Diabetes 1

Question 1

main use of glucose is as

Answer 1

brain fuel

Question 2

brain accounts for
__ % of body weight
__% of basal metabolic rate
__% of whole-body glucose utilization

Answer 2

Brain accounts for:
2.5% of body weight
**25% **of basal metabolic rate
50% of whole-body glucose utilization

Question 3

__ cannot synthesize or store glucose

Answer 3

brain cannot synthesize or store glucose

Question 4

where does brain get glucose?

Answer 4

it gets a continuous supply from circulation

Question 5

to maintain blood glucose concentration, we must coordinate glucose __ into circulation and __ out of circulation and into __

Answer 5

to maintain blood glucose concentration, we must coordinate glucose influx into circulation and efflux out of circulation and into tissues

Question 6

3 sources of glucose

Answer 6

1. intestinal absorption
2. glycogenolysis
3. gluconeogenesis

Question 7

glycogenolysis

Answer 7

glycogen to glucose

Question 8

gluconeogenesis

Answer 8

synthesis of glucose from non-carb sources

Question 9

glucose metabolism pathway steps

Answer 9

1. Glucose is phosphorylated and trapped in the cell
2. Becomes glycogen
3. Can become pyruvate (glycolysis) and then lactate, alanine, acetyl-Coa
4. acetyl-Coa can make ketones, citrate, fatty acids (then stored as triglycerides)

Question 10

3 types of cells in Islet of Langerhans (and what they secrete)

Answer 10

Beta-cell → insulin (70%)
Alpha-cell → glucagon (20%)
Delta and PP cells (10%)

Question 11

hormone most active during:
absorptive state
postabsorptive state

Answer 11

hormone most active during:
absorptive state: insulin
postabsorptive state: glucagon

Question 12

insulin site of action

Answer 12

liver
adipose
muscle

Question 13

glucagon site of action

Answer 13

mainly liver

Question 14

insulin
blood glucose conc
blood fatty acid conc
glycogen synthesis
glycogenolysis
gluconeogenesis

Answer 14

insulin
↓ blood glucose conc
↓ blood fatty acid conc
↑ glycogen synthesis
↓ glycogenolysis
↓ gluconeogenesis

Question 15

glucagon
blood glucose conc
blood fatty acid conc
glycogen synthesis
glycogenolysis
gluconeogenesis

Answer 15

glucagon
↑ blood glucose conc
↑ blood fatty acid conc
↓ glycogen synthesis
↑ glycogenolysis
↑ gluconeogenesis

Question 16

target tissues of insulin

Answer 16

liver
adipose
muscle

Question 17

insulin __ blood glucose conc

Answer 17

insulin decreases blood glucose conc

Question 18

insulin action

glucose uptake into tissues
glycolysis
glycogen synthesis
glycogenolysis (liver)
gluconeogenesis (liver & kidney)

Answer 18

increases glucose uptake into tissues
stimulates glycolysis
stimulates glycogen synthesis
inhibits glycogenolysis (liver)
inhibits gluconeogenesis (liver & kidney)

Question 19

insulin
decreases __ concentration
reduces __ output
promotes __ deposition and __ lipolysis
increases __ synthesis and inhibits __ breakdown

Answer 19

insulin
decreases blood glucose concentration
reduces hepatic glucose output
promotes fat deposition and inhibits lipolysis
increases protein synthesis and inhibits protein breakdown

Question 20

insulin action on the liver
main role is to inhibit

Answer 20

insulin action on the liver
main role is to inhibit glycogenolysis and gluconeogenesis

Question 21

indirect effects of insulin on liver
decrease __ flux to liver
decrease __ secretion

Answer 21

indirect effects of insulin on liver
decrease free fatty acid flux to liver
decrease glucagon secretion

Question 22

insulin action on adipose
less __ to be used to produce __

Answer 22

insulin action on adipose
less FA to be used to produce ketone bodies

Question 23

what is the incretin effect?

Answer 23

More insulin is secreted in response to an oral glucose load than to a matched IV glucose load

Question 24

the incretin effect is mediated by __ and __

Answer 24

the incretin effect is mediated by GLP-1 and GIP

Question 25

GLP-1 is secreted by __ cells GIP is secreted by __ cells

Answer 25

GLP-1 is secreted by **L** cells GIP is secreted by **K** cells

Question 26

purpose of glucose counterregulation

Answer 26

prevent hypoglycemia to preserve brain function

Question 27

glucose counterregulation steps

Answer 27

1. Insulin levels decrease (blood glucose 80-85) 2. Glucagon is secreted (blood glucose 65-70) 3. Epinephrine is secreted (blood glucose 65-70) 4. Cortisol & growth hormone (blood glucose 65-70) 5. Behavioral defense (blood glucose 50-55)

Question 28

sources of glucose during fasting

Answer 28

1. free glucose (extracellular fluid (ECF) and liver)

Question 29

during prolonged fasting __ becomes sole source of glucose __ broken down to AAs to be used for __ glucose utilization by __ and __ ceases glucose utilization by __ declines by half __ levels rise; brain uses __ for fuel at high concentrations

Answer 29

during prolonged fasting **gluconeogenesis** becomes sole source of glucose **muscle protein** broken down to AAs to be used for **gluconeogenesis** glucose utilization by **muscle** and **fat** ceases glucose utilization by **brain** declines by half **ketone** levels rise; brain uses **ketones** for fuel at high concentrations

Question 30

3 counterregulatory hormones

Answer 30

glucagon epinephrine cortisol and GH

Question 31

glucagon secretion is stimulated by decrease in __ levels (__ effect)

Answer 31

glucagon secretion is stimulated by decrease in **pancreatic islet insulin** levels (**paracrine** effect)

Question 32

glucagon is secondarily stimulated by increased __ input

Answer 32

glucagon is secondarily stimulated by increased **sympathetic** input

Question 33

glucagon primarily acts on __ and causes increased __ and __

Answer 33

glucagon primarily acts on **liver** and causes increased **glycogenolysis** and **gluconeogenesis**

Question 34

when is epinephrine critical?

Answer 34

when glucagon is deficient

Question 35

epinephrine is secreted from __ in response to __ signaling

Answer 35

epinephrine is secreted from **adrenal medulla** in response to **CNS** signaling

Question 36

epinephrine stimulate __ and __ gluconeogenesis stimulates __ glycogenolysis

Answer 36

epinephrine stimulate **hepatic** and **renal** gluconeogenesis stimulates **hepatic** glycogenolysis

Question 37

epinephrine reduces glucose uptake by __ and __

Answer 37

epinephrine reduces glucose uptake by **muscle** and **fat**

Question 38

epinephrine stimulates __ and limits __ from pancreatic islets

Answer 38

epinephrine stimulates **glucagon** and limits **insulin** from pancreatic islets

Question 39

cortisol and GH promote __ and reduce __ glucose utilization

Answer 39

cortisol and GH promote **gluconeogenesis** and reduce **peripheral** glucose utilization

Question 40

which counterregulatory hormones are not critical?

Answer 40

cortisol and GH

Question 41

gluconeogenesis require __ (from liver and kidneys) __ do 10-20% of glucose production

Answer 41

gluconeogenesis require **G6Pase** (from liver and kidneys) **kidneys** do 10-20% of glucose production

Question 42

renal glucose production is regulated by __ and __, but NOT __

Answer 42

renal glucose production is regulated by **insulin** and **epinephrine**, but NOT **glucagon**

Question 43

what is the primary glucose counterregulatory hormone?

Answer 43

glucagon

Question 44

diabetes prevalence in US

Answer 44

13%

Question 45

diabetes is leading cause of __ in US diabetes increases risk of __ and __

Answer 45

diabetes is leading cause of **blindness** in US diabetes increases risk of **CVD** and **death**

Question 46

diagnosing diabetes fasting plasma glucose __ OR 2-hour plasma glucose __ during a __ oral glucose tolerance test OR random plasma glucose __ with symtpoms of hyperglycemia OR HbA1c __

Answer 46

diagnosing diabetes fasting plasma glucose ** ≥126 mg/dl ** OR 2-hour plasma glucose ** ≥200 mg/dl** during a **75G** oral glucose tolerance test OR random plasma glucose **≥200 mg/dl** with symtpoms of hyperglycemia OR HbA1c **≥ 6.5%**

Question 47

HbA1c reflects

Answer 47

Hemoglobin A1c reflects the average blood glucose concentration over a 2-3 month period.

Question 48

HbA1c is used to

Answer 48

1. diagnose diabetes 2. monitor blood glucose control in patients with diabetes

Question 49

HbA1c measures

Answer 49

glycated hemoglobin

Question 50

what is glycated hemoglobin

Answer 50

hemoglobin with glucose irreversibly attached

Question 51

type 1 diabetes

Answer 51

an autoimmune process in which β-cells are destroyed, resulting in absolute insulin deficiency (~5-10% of diabetes cases)

Question 52

type 2 diabetes

Answer 52

characterized by insulin resistance and β-cell dysfunction, resulting in relative insulin deficiency (~90% of diabetes cases)

Question 53

people with type 1 diabetes have no

Answer 53

beta cells

Question 54

ominous octet of hyperglycemia

Answer 54

1. decreased insulin secretion 2. decreased incretin effect 3. decreased glucose uptake 4. increased HGP 5. increased glucagon secretion 6. increased lipolysis 7. increased glucose reabsorption 8. NT dysfunction

Question 55

type 1 diabetes age at onset weight family history autoantibodies (present?) insulin requiring insulin sensitivity rise of DKA

Answer 55

type 1 diabetes age at onset: **any, but majorty < 25** weight: **typically lean but can be overweight** family history: **infrequent (may be family history of autoimmune disease** autoantibodies (present?): **present** insulin requiring: **yes** insulin sensitivity: **normal** rise of DKA: **high**

Question 56

type 2 diabetes age at onset weight family history autoantibodies (present?) insulin requiring insulin sensitivity rise of DKA

Answer 56

type 2 diabetes age at onset: **any, but majority >25** weight: **>80% overweight/obese** family history: **frequent** autoantibodies (present?): **absent** insulin requiring: **variable** insulin sensitivity: **decreased** rise of DKA: **low**