Unit 5: Week 5 Flashcards
What is glucose and how do we obtain it?
Glucose is a simple carbohydrate (monosaccharide) and is widely used as a source of energy in the body.
Breakdown of starchy good in the digestive system leads to glucose being absorbed into the blood and processed in the liver via the hepatic portal veins.
What is glycogen?
Because glucose is soluble it is converted to glycogen to be stored (which is insoluble).
The highest amount is found in muscle tissue but the highest concentration is found in the liver due to it being the main processing organ.
What is hypoglycemia and hyperglycemia?
Hyperglycemia- a decrease in blood glucose levels typically below 4.0. This can lead to impaired function of nervous system eg. confusion, loss of consciousness, shakiness, palpitations (heaty trying to get more glucose to important areas), increased heart rate, easily irritated.
Hyperglycemia- an increase of blood glucose level. If chronic it could result in damage to blood vessels (through glycation) and may lead to nerve damage (through blood vessels that supply them). This leads to loss of/limited sensation in the limbs (especially lower limbs) so when there is an injury this could go unnoticed and get worse over time, leading to infections/amputations (repetitive stress).
What are the fluctuating levels of glucose?
They fluctuate during periods of food intake and activity but should stay within certain limits.
Fasting- normally 4.0-5.9 (ideally below 5.5)- Pre-diabetic- 5.5-6.9
Post prandial (after eating)- normal is equal to or less that 11.1, diabetic is over 11.1
90 mins post prandial- normal is less than or equal to 7.8 (7 within 2 hours)
What is insulin? What is glucagon?
Insulin is produced by the beta cells of the islet of langerhans in the pancreas. It is a peptide hormone meaning it’s water soluble and interacts with cells via the second messenger system. Most cells are sensitive to insulin, in particular muscle and adipose tissue. Acts to decrease blood glucose levels and released after eating.
glucagon- released by alpha cells of the islit of langerhans in the pancreas. It’s a peptide hormone so it’s water soluble and interacts via the second messenger system. It acts to increase blood glucose levels and is generally released during a period of fasting.
What is the effect of insulin?
Insulin acts to decrease blood glucose level by causing cells to become more permeable to glucose,
promote glycolysis breakdown of glucose for energy
promote glycogenesis convert glucose to glycogen
inhibit lipolysis break down of fats for energy
an overall shift from the metabolism of fat and towards glucose. increased triglyceride synthesis
What are the effect of glucagon?
Glucagon works to increase blood glucose levels by:
- Converting stored glycogen into glucose
- Promoting gluconeogenesis (production of glucose from non carbohydrate sources eg fatty acids from adipose tissue)
Glucagon only raises BGL to the minimum amount for the body to function (not high BGL)- as a result it’s difficult to overdose on it, unlike insulin which can be overdosed on.
What is DMT2?
Reduced sensitivity towards insulin or the body doesn’t produce enough
Glucose → increased insulin produced by pancreases → overtime body is unable to keep up with metabolic demand → unable to produce enough insulin
Increase BGL
What is DMT1?
the body doesn’t produce insulin. - (may produce insulin but not enough) (Tcells attack beta cells).
It is diagnosed earlier than T2DM but T2DM is getting diagnosed younger due to increased obesity rates.
What are risk factors for DMT2? (10)
• Obesity- heavily linked with Dmt2 thought to due to insulin sensitivity
due to increased excess adipose tissue that releases free fatty acids and adipose kinase
• lack of exercise - activity decreases BGL as it is recruited by muscle
• advanced age due to decreased metabolism and increased fat
• Genetic factors - close relative with T2DM increases risk of developing T2DM
• Ethnicity- Asians ✗ 5 more likley than caucaisens. Middle eastern increased risk. African Caribbean ✗ 4 more likey than caucuisens
• smoking
• unealthy diet. Increased glucose and fat
- stress - Cortisol released- increase BGL
• other conditions- Gestational diabetes - diabetes when pregnant- resolves
after delivery but they have increased risk of T2DM
• Medication - Corticosteroids- increase production of cortisol
What are some symptoms of DMT2?
-Blurry vision- lens in eye swells 1- Changes shape
• increased urine - kidneys filter blood and reabsorbed all glucose - due to increased levels kidneys are unable to do this which causes an osmotic pressure
gradient for water causing more urine.
• increased Thirst due to high osmolarity of blood
• General fatigue - glucose is being expelled in urine and also unable to be utilised due to insulin insensitivity
- recurring skin, gum, bladder infections - more glucose in sweat and urine
is a food source for bacteria (diabetics also have reduced immunity to deal with infections)
-Dry itchy skin - glycation of collagen (college has most of the water)
- weight loss - insulin converts sugar to glycogen to store. Decreased storage and less utilisation of insulin→ increased lipolysis and protein catabolism.
• slow-healing cuts and bruising → decreased blood Supply
-Neuropathy → decreased blood supply to nerves
- Effects on ANS → (men) impotence, decreased sweating, increased abdominal bloating etc
What is used to calculate risk?
BMI is recorded for diabetes risk. However BMI can be inaccurate as BMI dosen’t account for muscle mass. it is also inaccurate for people of african origin as BMI data heavily relies on European populations.
There is a shift to using waist circumference
10% of body fat is stored in the abdominal cavity/visceral fat as opposed to subcutaneous. fat.
This type of fat is better linked to T2DM, heart disease, cancers.
What are the major complications of DMT2?
① Retinopathy- Damage to the retina resulting in abnormal vision caused by abnormal BV growth damage which can cause leaks that can damage the retina - generally non revisable but can prevent deterioration. T risk of cataracts
③ Nephropathy The nephron is the functional unit of the kidney - kidney damage - Due to increased pressure from glucose from blood → loses filtering function over time
④ vascular disease - T2DM increases progression of atherosclerosis which restricts/blocks blood supply esp in the lower body (not enough nutrients delivered/waste products removed
⑤ ischemic users are harder to heal and antibiotics cannot reach the area effectively- bone infection can also occur (not many antibiotics targetbone + difficult to buid up high concentration). Also caused by dry hardend skin - harder calosed → skin breakdown.
Coronary heart disease
⑥ Damage to Bu in nerves I reduced protective sensations (areas further
from the trunk likley to be effected first). (longest nerves Trish)
⑦ stroke weakened BV
What are ketones?
In lypolisis fat is broken down into fatty acids and fat- the liver then turns this
into ketone bodies - they can be used as energy but increase blood acidity
