Ed

Question 1

Ed has gylcated Hb of 11% (HbA1C). Why might this be a bad thing?

Answer 1

• Normal range is 4-5.6%
• Glycated Hb levels are an indication of how much plasma glucose has been curculating (on average) for the last 3 months so it means that Ed has had more sugar in his blood than normal over this time period.

Question 2

Why is high cholesterol a risk factor for MI/stroke/vascular disease?

Answer 2

• Low density “bad” cholesterols can form fatty deposits (plaques) that contribute to athlerosclerosis (hardening and narrowing of arteries).
• Dysfunction of endothelial cells because of plaque build-up results in increased risk of thrombus formation and cause emboli
• These lead to MI, stroke and/or PE depending on where the clot goes and messes you up (heart, brain and lungs respectively)

Question 3

What is classified as high blood pressure in Australia?

Answer 3

140/90

Question 4

Why is hypertension not good for you?

Answer 4

Can lead to:

• LHS heart failure (heart has to pump harder and fills more during diastole so heart hypertrophies)
• Ischaemic stroke
• Kidney disease

Question 5

Why is high cholesterol a risk factor for MI, stroke, vascular disease, etc?

Answer 5

• Low density (bad) cholesterol can form plaques (blockages) which contribute to athlerosclerosis (hardening and narrowing of arteries)
• Endothelial dysfunction can encourage thrombus formation which can lead to emboli therefore MI/stroke/PE

Question 6

Name two different types of stroke.

Answer 6

• Ischaemic stroke = because of a clot causing ischaemia (dec. oxygen) in brain
• Haemorrhagic stroke = weakening of vessel walls overtime leads to eventual rupture then you bleed everywhere :(

Question 7

Why would a physician order three tests for diabetes?

Answer 7

• Sometimes one test will fail on account of the patient trying to skew results or upon accident. eg. fasting glucose when Ed has already had a coffee = unreliable result (will look like high blood glucose)
• There may be undetectable glucose in urine, especially if Ed hasn’t eaten for two days prior to the test (will look like there is no glucosuria)
• Diabetes might be relatively new or still developing (glycated Hb might be in normal range)

Question 8

Name a primary (direct) consequence of diabetes (TI or TII).

Answer 8

• Impaired glucose uptake causes distrubed metabolism in most cells throughout the body (except nerves and skeletal muscle because their use of glucose is insulin independent)

Question 9

Why is insulin unimportant in a fight or flight response?

Answer 9

• Brain and exercising muscle involved don’t require insulin to enable glucose transport
• Note: SNS activation AND adrenaline release inhibit insulin release

Question 10

Name 5 factors that influence insulin secretion from islet beta-cells.

Answer 10

1. Blood glucose (inc. bg = inc. insulin secretion)
2. Blood AA (inc. AA = inc. insulin secretion)
3. PNS (inc. PNS = inc. insulin secretion)
4. GI hormones (inc. GIH = inc. insulin secretion)
5. SNS and adrenaline (inc. SNS = dec. insulin secretion)

Question 11

Name 5 direct consequences of insulin secretion.

Answer 11

1. Dec. blood glucose
2. Dec. blood AA
3. Dec. blood FFA
4. Inc. fuel storage
5. Inc. protein synthesis

Question 12

What is:
a) Renal threshold
b) Renal transport maximum
and how do these factors affect a diabetic?

Answer 12

a) Renal threshold = 180 mg/dL
b) Renal transport max = 375 mg/dL
If glucose is able to be removed from the plasma, glucose spills over into the urine (glucosuria)

Question 13

What is a consequence of glucosuria?

Answer 13

Dehydration!

• Glucose contributes to osmotic gradient (so we will also get Na loss = potench hyponatremia)

Question 14

What is pressure natriuresis?

Answer 14

• A decrease in Na content throughout the body (natriuresis) in an effort to reduce high blood pressure (pressure)
• RAAS is NOT responsible for this but a decrease in RAAS makes this system more sensitive to changes in plasma Na

Question 15

What happens when cardiac output (Q) is decreased?

Answer 15

• Less oxygen perfusion to tissues = tiredness and can also lead to impaired vision and cognitive function
• Afterload becomes higher to try and get Q back up
• Kidneys release EPO = increase RBC count to combat hypoxia (not good for chronic dehydration as the cells will block each other from getting through narrow passages - bottleneck effect)
• Renal system will sense decreased Na and try to retain more Na (why?)

Question 16

Have you looked at the mind map in your lecture notes? It is v useful.

Answer 16

:)

Question 17

What are three long-term consequences of untreated TIID?

Answer 17

• Decreased NO release (anti-coagulant) because inc. pressure and inc. blood viscosity causes endothelial damage.
• In patients with athlerosclerosis, we have plaque on endothelial cells which means no PGI2 (anti-proliferative) or NO (anti-coagulant) release –> disregulated cholesterol
• Inflammatory response because of oxidated lipids = LOTS of damage due to complement bc plaques are foreign Ags
• Oxidative stress damages spaces like the ECM

Question 18

How is it that diabetic men can suffer from erectile dysfunction?

Answer 18

• Nerve damage means that there is less signal going to/from brain
• Inc. SNS stimulation to penile arterioles = vasocontriction = no erection because we need penile arterioles to dilate
• PNS causes dilation of arterioles = compression of veins = blood isn’t draining from penis = erection

Question 19

How does viagara (sildenafil) help with ED?

Answer 19

• Blocks expression of PDE5 which usually breaks down cGMP
• cGMP helps dilation of blood vessels
• the more cGMP you have around, the better your erection will be

Question 20

Why doesn’t viagara cause systemic vasodilation?

Answer 20

• Only certain cell type have receptors for PDE5 (lung and penis)
• Sildenafil was initially used to treat pulmonary hypertension but of course a big side effect is having an erection so it didn’t really last too long as a preferred treatment

Question 21

Name 9 consequences of sysemic (arteriolar) vasodilation.

Answer 21

1. Hypotension (bp decrease)
2. Ischaemia due to decreased blood blow
3. Impaired vision
4. Dec. ability to maintain and erection
5. Inc. SNS = vomit
6. Dizziness
7. Coma
8. Dec. cardiac output
9. Upregulate RASS (takes time though)

Question 22

Ed has some rebar go through his foot. He doesn’t think it’s that bad because he can’t feel the pain, why?

Answer 22

• Diabetic Neuropathy means that he has lost sensation in his extremeties
• He is also probably dehydrated, meaning there is less perfusion of oxygen around his body due to reduced blood volume

Question 23

There isn’t much blood coming from his boot when Ed steps on the rebar. This indicates to him that it might not be that bad. What has happened?

Answer 23

• Ed has reduced blood volume because of dehydration which means he isn’t going to be bleeding as much.
• There is also probably a blockage somewhere decreasing blood flow even further

Question 24

In the hospital, Ed mentioned that he had gained a considerable amount of weight in the previous few days to a week (can’t take his shoes off and his belt has gone up 2-3 notches). What has happened here?

Answer 24

• Hyponatremia (low Na) in kidneys means that is being aldosterone released in an effort to retain Na (therefore water). The volume increases too much and spreads which causes extracellular oedema.

Question 25

Why is Ed’s (leg) swelling better in the morning?

Answer 25

• Gravity helps the fluid to pool in the legs when standing
• Lower bp while sleeping
• Lower glucose in serum

Question 26

Name 5 risk factors for peripheral artery disease.

Answer 26

1. Hypertension
2. Age
3. Smoker
4. Diabetes
5. Diet/exercise
6. High cholesterol (this one isn’t as important)