Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
98 Cards in this Set
- Front
- Back
|
Describe the structure of the pancreas.
|
The pancreas:
1) a triangular organ located between the duodenum and stomach 2) comprises alpha, beta, delta and F-cells (endocrine) surrounded by (exocrine) acinar cells. 3) Islets of Langerhans are infiltrated by blood capillaries and surrounded by acinar cells. 4) Glucagon and insulin are secreted by A & B cells respectively, working antagonistically on glucoregulation. |
|
|
What are the functions of insulin?
|
Insulin acts to reduce blood sugar levels by:
1) rendering peripheral body cells more permeable to glucose 2) stimulating glycogenesis 3) stimulating glyconeogenesis |
|
|
What is the action of glucagon?
|
Glucagon increases blood sugar levels by:
1) rendering peripheral cells less permeable to glucose 2) stimulating glycogenolysis & lipolysis 3) stimulating gluconeogenesis 4) inhibiting glyconeogenesis |
|
|
Explain the difference between type 1 and type 2 diabetes mellitus
|
Type 1 diabetes (early onset) - frank deficiency of insulin production, often due to autoimmune destruction of pancreatic B-cells.
Type 2 diabetes (late onset) - often due to reduced insulin sensitivity in peripheral cells. |
|
|
Identify eight long term problems associated with hyperglycemia.
|
Long term sequelae of hyperglycemia include:
1) sensory neuropathy 2) microvascular disease (peripheral arterial disease) 3) macrovascular disease (stroke, MI) 4) glycosylation of tissues affecting connective tissue 5) diabetic retinopathy 6) nephropathy 7) ulceration of extremities 8) gangrene, limb loss |
|
|
What is homeostasis?
|
Homeostasis is the maintenance of a stable internal environment. Ths involves constant adustment.
|
|
|
What two body systems maintain homeostasis?
|
Homeostasis is maintained by the endocrine and central nervous systems.
|
|
|
Outline the 4 classic clinical signs of Type 1 Diabetes Mellitus.
|
Classic symptoms/signs of Diabetes Mellitus are:
1) Polyuria (excessive urination) 2) Polydypsia (excessive thirst) 3) Weight loss 4) Fatigue |
|
|
What is the action of metformin?
|
Metformin lowers plasma glucose concentrations by
inhibiting glucose synthesis and release at the liver. |
|
|
Is Type 1 or Type 2 Diabetes Mellitus more common?
|
Type 2 DM is more common, accounting for 90% of cases in the US.
|
|
|
What are the four types of diabetes?
|
1) Diabetes Mellitus (Type 1)
2) Diabetes Mellitus (Type 2) 3) Diabetes Insipidus 4) Gestational Diabetes |
|
|
Why is a patient with Type 2 Diabetes at increased risk of lower limb amputation?
|
Diabetes has a detrimental effect on vascular health, neurological ststus, ability to withstand infection, immune functioning, tissue viability and musculoskeletal health. These are all factors that render a foot vulnerable to damage that can lead to amputation.
|
|
|
What causes polydypsia in diabetes?
|
Excessive thirst occurs as a result of the osmotic diuretic effect of excess glucose in the blood (draws water out of the tubules with it).
|
|
|
What causes the excessive urination seen in diabetes?
|
If the concentration of a substance exceeds the ability of the kidney tubules to reabsorb it, the effect will be to draw water out of the tubules. The substance will act as an OSMOTIC DIURETIC.
|
|
|
Give an example of a lipid based hormone.
|
Thyroid hormones are lipid based hormones.
Testosterone is also a lipid-based hormone. |
|
|
Give an example of peptide hormone.
|
Insulin, glucagon and adrenaline are all peptide hormones.
|
|
|
True or false: Peptide hormones are hydrophilic and cannot cross the cell membrane.
|
True. Peptide hormones such as insulin and glucagon cannot cross the cell membrane.
|
|
|
What are the short term effects of hyperglycemia?
|
1) Hyperglycemia is detected by receptor cells in pancreas
2) B-cells release insulin into bloodstream 3) Insulin renders cell membranes more permeable to glucose by activating glucose carrier proteins 4) glucose is transported into liver cells by facilitated diffusion 5) glucose is converted to glycogen (glycogenesis) and stored in liver 6) if liver cells are saturated with glycogen, glucose is converted to fatty acids instead 7) blood glucose levels fall |
|
|
What organ monitors blood glucose levels?
|
The pancreas has glucose receptor cells which monitor the concentration of blood glucose.
|
|
|
What are the short term effects of hypoglycemia?
|
1) Hypoglycemia is detected by receptor cells in the pancreas
2) Pancreatic A-cells secrete glucagon into bloodstream 3) Glucagon stimulates mobilisation of stored glycogen to glucose 4) blood glucose levels rise |
|
|
What is the stimulus that stops insulin secretion?
|
Insulin secretion stops when blood sugar levels fall within "normal" range.
|
|
|
What stops glucagon being produced?
|
When receptors in the pancreas detect blood sugar is within "normal"range, the A-cells stop secreting glucagon.
|
|
|
Is the control of blood glucose by insulin/glucagon a negative or positive feedback system?
|
Glucoregulation by insulin/glucagon is a negative feedback system.
|
|
|
Name some PEPTIDE hormones
|
Peptide hormones include:
- All anterior pituitary hormones - Adrenaline - Insulin - Glucagon |
|
|
What is the "normal" range for blood glucose?
|
This varies between individuals, but commonly is between 4mmol/L - 7 mmol/L
|
|
|
Give a definition of diabetes.
|
Diabetes is a syndrome characterised by chronic hyperglycemia, insulin deficiency or insensitivity to its action.
|
|
|
Name three common causes of tissue necrosis.
|
Necrosis can be caused by:
1) Ischaemia 2) Neuropathy 3) Infection |
|
|
Name four ways in which Type 2 diabetes can be treated.
|
T2 DM treatments may include:
- Drug treatment - Dietary control - Lifestyle change/exercise - regular monitoring |
|
|
What is ketoacidosis and why/when does it occur?
|
1) When cells cannot use glucose for fuel, they mobilise fats instead
2) Ketones are the acidic metabolites of lypolysis 2) Ketones accumulate in the blood faster than they can be excreted by kidneys 3) Blood pH becomes acidic (=ketoacidosis) |
|
|
What hormones oppose the effects of insulin?
|
Glucagon and growth hormone both oppose the effects os insulin.
|
|
|
Why is hyperglycemia the hallmark of diabetes?
|
Hyperglycemia results from the body's inability to use or store excess glucose, which remains circulating in the blood.
|
|
|
What is the most common cause of kidney failure?
|
Diabetes is the commonest cause of kidney failure (nephropathy).
|
|
|
Define "neuropathy"
|
Neuropathy is the degeneration or inflammation of the peripheral nerves.
|
|
|
What causes the foot to become at risk?
|
- sensory neuropathy
- poor arterial supply - poor venous drainage - a compromised immune system deformity skin changes history of ulceration |
|
|
Name some examples of conditions that would put the foot at risk.
|
Diabetes with complications
RA with complications PVD Chronic venous insufficiency Symptomatic HIV/AIDS Immunosuppressed/steriod therapy Hansens Osteoporosis Oedema Age |
|
|
What are the NICE criteria for LOW RISK?
|
Low risk =
- Normal sensation & - Palpable pulses |
|
|
What are the NICE criteria for INCREASED RISK?
|
Increased risk =
- Neuropathy or - Absent pulses or - Other risk factors |
|
|
What are the NICE criteria for HIGH RISK?
|
High risk =
- Neuropathy or - Absent pulses plus: - Deformity, Skin changes, Previous ulcer |
|
|
List the basic NICE guideline categories / risk gradings for the at risk foot
|
1- low current risk
2- at increased risk 3- high risk 4- ulcerated |
|
|
The 5 key aims of diabetic foot management are...
|
Diabetic foot aims:
1. Team mgmt 2. Foot exam - detect risk factors 3. Classify risk 4. Education 5. Prevent complications |
|
|
What intervention would you provide to a "low current risk" foot?
|
Low current risk would get:
management plan & footcare education |
|
|
What intervention would you provide to a "increased risk" foot?
|
Increased risk foot would get: regular review with foot exam
|
|
|
What intervention would you provide to an "at high risk" foot?
|
High risk foot needs:
Frequent review Frequent examination Frequent evaluation of careplan |
|
|
What intervention protocol would you provide to an ulcerated foot?
|
If foot is ulcerated:
MDT in 24hrs Treat vascular insufficy Wound mgmt AB therapy Foot pressure Mgmt |
|
|
What are the four key questions to ask if you have a diabetic patient?
|
1- Is pt At Risk? Why?
2- Risk of becoming high risk? 3- How can I prevent this? 4- How best managed? |
|
|
What is an acceptable HbA1c level?
|
HbA1c acceptable =
below 7% and not above 9% |
|
|
What is HbA1c a measure of?
|
of blood glucose control over 120 days
|
|
|
What does the % of glycosylated haemoglobin directly reflect?
|
...it reflects the amount of glucose in the bloodstream
|
|
|
Why is HbA1c levels taken only every 120 days?
|
because 120 days is the lifespan of a red blood corpuscle
|
|
|
Name some characteristics of ischaemic ulcers
|
Ischaemic ulcers:
on borders of foot cool to touch punched out appearance slough not granulation glassy appearance painful |
|
|
Name some characteristics of neuropathic ulcers
|
Neuropathic ulcers:
- plantar, at sites of pressure - hot to touch |
|
|
State the classic clinical presentation of early Charcot arthropathy
|
Temperature difference of 2 degrees
Swelling Redness Possible discomfort Bounding pulses |
|
|
What is "Charcot foot"?
|
Gross midfoot deformity secondary to long-term distal autonomic/sensory neuropathy.
|
|
|
Immediate management of Charcot foot includes?
|
Offloading
|
|
|
Would you X-ray an early Charcot foot?
|
not in the first few weeks, because nothing will be detectable on x-ray.
|
|
|
What are the two types of Charcot changes you might see on X-ray?
|
1) hypertrophic changes; or
2) atrophic changes |
|
|
Classic signs of early Charcot foot...?
|
1) increased temperature
2) redness 3) swelling 4) bounding pulses 5) pain in a neuropathic foot |
|
|
The three stages of a Charcot foot are?
|
1) destructive phase
2) coalescent phase 3) reconstructive phase |
|
|
NICE guideline LOW risk category is...
|
LOW risk:
- palpable pulses - full sensation |
|
|
NICE guideline INCREASED risk is...
|
INCREASED risk:
- neuropathy - absent pulses - other risk factor |
|
|
NICE guideline HIGH risk is...
|
HIGH risk:
- neuropathy - absent pulses - bony deformity or skin changes or previous ulcer |
|
|
Causes of Charcot include...?
|
M-O-N-A
Microfracture [mechanical stress] Osteopenia Neuropathy Altered bloodflow |
|
|
Charcot has two types on X-ray - what are they?
|
Atrophic:
common in forefoot met heads like "sucked candy" osseous resorption Proliferative: common at midfoot increased bone mass laid down |
|
|
What are the three stages of Charcot foot?
|
Stage 1 - Destruction
Stage 2 - Coalescence Stage 3 - Reconstruction |
|
|
What pathological processes occur at the DESTRUCTIVE stage of Charcot?
|
bony fragmentation & debris
ligamentous laxity allows joint to disarticulate soft tissue swelling |
|
|
What process is occuring at the COALESCENT phase of Charcot?
|
avascular necrosis
new bone laid down on dead trabeculae resorption of bony debris |
|
|
What occurs during RECONSTRUCTION stage of Charcot?
|
the affected joints fuse
|
|
|
Common elements in patient history with Charcot?
|
- diabetic for >10 years
- may have history of trauma - neuropathic - (may be) hypermobile in early stages - painful foot |
|
|
What radiographic changes would you expect to see with Charcot?
|
Atrophic (bone loss):
- "sucked-candy" met heads - "hour-glass" phalanges Hypertrophic (extra bone growth): - osteochonrdal fragments/debris in joint - marginal osteophytes - debris absorption - callus formed on healed Fx - |
|
|
Ddx to Charcot in early stages?
|
Osteomyelitis
Fracture Cellulitis |
|
|
Name the five common sites of Charcot in the foot
|
1) forefoot
2) tarso-metatarsal (midfoot) 3) N-C, T-N, or C-C joints 4) ankle 5) calcaneus |
|
|
Why wouldn't you use an X-ray in early stage Charcot?
|
X-ray might be normal in early Charcot
|
|
|
What imaging modality should you use in early Charcot?
|
A bone scan - but it will not help you differentiate between
|
|
|
What is the disadvantage of using a bone scan in early Charcot?
|
It will not help you differentiate between osteomyelitis and Charcot foot.
|
|
|
What does a bone scan tell you?
|
A bone scan tells you there is increased blood supply to a bone.
|
|
|
Treatment for early Charcot includes...?
|
Immediate immobilisation for 1mth
Casting Exclude infection |
|
|
When can a Charcot patient come out of a cast?
|
No continuing destruction on X-ray
Temperature of both feet within 2degrees |
|
|
Minimum period in a cast with Charcot?
|
About 6 months if not longer
|
|
|
What would you put a charcot patient in when they come out of a cast?
|
- an orthotic walker with a moulded insole
- rocker shoe modification |
|
|
Pharmacological treatment for Charcot?
|
biphosphonates (but little evidence)
|
|
|
What are the common signs of motor neuropathy in the diabetic foot?
|
lesser toe clawing/prominent PMP
extensor substitution intrinsic muscle weakness absent ankle reflexes foot drop if large muscles involved |
|
|
What are the signs of autonomic neuropathy in the diabetic foot?
|
reduced sweating --> anhydrosis
dorsally extended veins (Ward's sign) peripheral oedema warm, pink foot |
|
|
What are arteriovenous shunts ?
|
arteriovenous shunts are microvessel "expressways" that enable blood to bypass the capillary bed and carry blood directly from the arterial to the venous side.
they are under autonomic control in neuropathy they remain permanently open, so blood bypasses the capillary bed at high speed |
|
|
What signs indicate that arteriovenous shunting might be occurring in the diabetic foot?
|
bounding pulses (blood at high speed)
peripheral oedema peripheral tissues lack nutrition dorsally extended veins |
|
|
Name two common systemic signs of autonomic neuropathy
|
gustatory sweating
& erectile dysfunction |
|
|
What random blood glucose levels are classified as representing Impaired Glucose Tolerance?
|
between 5.6 - 7 mmol/L
|
|
|
What are normal limits for random blood glucose?
|
4-8 mmol/L
|
|
|
What is a normal HbA1C level?
|
below 8% is ok
|
|
|
What relationship is there between HbA1C levels and diabetic complications?
|
there is a positive correlation between HbA1C and the rate at which diabetic complications occur
|
|
|
Name the 8 pillars of Diabetes Management:
|
1. Blood glucose control
2. HbA1C <8% 3. Reduce cholesterol 4. Reduce Blood Pressure 5. Reduce BMI 6. Exercise 7. Smoking cessation 8. Drinking reduction |
|
|
Name four targets for antidiabetic drug action, the class of drug and an example of a drug in that class.
|
1) liver (Biguanide- Metformin)
2) muscle (Biguanide-Metformin) 3) Pancreatic Beta cell membrane (Sulphonylureas-Gliclazide) 4) Gut (alpha glucosidase inhibitors - acarbose) |
|
|
What class of antidiabetic drug increases insulin sensitivity of peripheral tissues?
|
Thiazolidinediones
|
|
|
What aspect of Diabetes can an HbA1C level predict?
|
it can predict many chronic complications of diabetes
|
|
|
What is the relationship between being sedentary and T2D?
|
there is an inverse relationship between being sedentary and the risk of developing T2D
|
|
|
Name 4 benefits of exercise for a T2D patient.
|
1. reduced body fat
2. improved dyslipidaemia 3. Reduced Blood Pressure 4. Increased Insulin Sensitivity |
|
|
What stimulates glucagon secretion?
|
low blood sugar levels
|
|
|
Name three "counter-regulatory" hormones
|
Glucagon
Cortisol Adrenaline |
|
|
State the four main headings of cardiovascular complications in T2D.
|
1. Micro-vascular
2. Macro-vascular 3. Hypertension 4. Dyslipidaemia |
