GLUCOSE Flashcards
principal and almost exclusive carbohydrate circulating in the blood
central, pivotal point of carbohydrate metabolism
Glucose
the most important glucose consumer.
Brain
CNS consumes about ____of glucose used by the body
50%
Glucose can be derived from
- Diet
- From body stores like glycogen
- Endogenous Synthesis from proteins or glycerol or TAGS
Metabolism of glucose molecule to pyruvate or lactate energy
Decrease blood glucose since glucose is consumed to produce lactate/pyruvate
Glycolysis
Formation of glucose-6-phosphate from non- carbohydrate sources
Increases blood glucose; new glucoses are formed from other sources
Gluconeogenesis
Breakdown of glycogen to glucose for use as energy
Increases glucose due to glycogen degradation
Glycogenolysis
Conversion of glucose to glycogen for storage
Decreases glucose since excess glucoses in the
body is stored in the liver and skeletal muscle as
glycogen
Glycogenesis
Conversion of carbohydrates to fatty acids
Decreases glucose since carbohydrates are
converted into fatty acids and stored as fats
Lipogenesis
Lipolysis
Breakdown of fats; fats are used as energy
Hyperglycemic Hormones
Glucagon Epinephrine Cortisol Growth Hormone Thyroxine
Hypoglycemic Hormone
Insulin
Regulator hormone
Inhibits release of growth hormone, insulin, and glucagon
Somatostatin
Standard Clinical Specimen
Fasting Blood
Plasma
Venous Blood
Fasting blood sugar should be obtained after
8-10 hrs
Venous blood has ______ glucose levels compared to arterial blood
Lower
Capillary Blood has _______ glucose levels compared to venous blood
Higher
Rationale: Higher kay waray pa magamit or ma catabolize an glucose ha capillary blood compare to venous blood
Whole blood gives approximately _______glucose levels than serum or plasma
10-15% Lower
Whole blood glucose conversion into serum or plasma level
Multiply value by 1.15
A serum specimen is appropriate for glucose analysis if serum is separated from the cells within
30-60 minutes
Glucose is metabolized at room temperature at a rate of
7mg/dL /hr
Breakdown of fats; fats are used as energy
2mg/dL /hr
10% contamination with 5% dextrose will increase glucose by
500 mg/dL or more
CSF glucose concentration is approximately______ that of plasma concentration
60-70 mg/dL or 60%
Blood glucose should be obtained _______ before the spinal tap
1-2 hours
CSF for glucose analysis should be performed
immediately. If delay in measurement is unavoidable, the sample must be centrifuged and stored at
4 C or at –20 C
Glycemic factors such as glucagon are released when glucose levels reach
65-70mg/dL
Observable signs and symptoms of hypoglycemia appear when glucose levels reach
50-55mg/dL
Critical value for glucose is _________________;
excessively low glucose values can cause severe CNS dysfunction especially if blood glucose value drops to__________
40 mg/dL
20-30 mg/dL
low blood glucose concentration, typical symptoms and symptoms alleviated by glucose administration
Whipple’s Triad
Hyperglycemia Laboratory Findings
- INCREASE glucose in plasma and urine
- increase in urine specific gravity
- Ketones in serum and urine
- Decreased blood and urine pH (acidosis)
- Electrolyte imbalance (decrease Na+ and HCO3+, increase K+)
Rationale:
1. Glucose Renal threshold of 160-180 mg/dL through reabsorption. In the presence of normal renal function, plasma glucose reaches a “period of plateau” around 300-500 mg/dL, that is glucose urinary excretion will match the overproduction, causing the plateau.
- Serum osmolality is high; Na+ conc. tend to be lower due in part to losses/ polyuria and in part to a shift of water from cells.
- Type 1 DM more likely to produce ketones.
- Ketoacidosis resulting to pH imbalance results from dehydration, electrolyte imbalance and acidosis.
- Decrease HCO3 and tCO2 due to kussmaul-kien respiration
Increase in blood glucose concentration
Toxic to beta cell function and impairs insulin secretion
Causes:
- Stress,
- severe infection,
- dehydration or pregnancy,
- pancreatectomy,
- hemochromatosis,
- insulin deficiency or abnormal insulin receptor.
Hyperglycemia
FBS LEVEL Hyperglycemia
FBS Level: >/= 126 mg/dL
Group of metabolic disorders characterized by hyperglycemia resulting from defects in insulin secretion, insulin receptors or both.
Diabetes Mellitus
Diagnostic plasma glucose concentration for DM
> /= 126 mg/dL on more than 1 testing
Glucosuria occurs when the plasma glucose levels exceed________ with normal renal function
160-180mg/dL
Ratio of B-hydroxybutyrate to acetoactate in severe DM
6:1
