PBS 2.1.4
Clues to our overall health hidden in fluids (blood and urine)
Blood Work - Examination of blood cells & analysis of molecules that travel within blood
Blood composed of 3 types of cells/cell fragments: red blood cells (erythrocytes), white blood cells (leukocytes), and platelets (thrombocytes) floating in plasma
White blood cells - large role in the immune system
Platelets - cell fragments responsible for clotting blood during bleeding
Red blood cells - major carriers of both iron and oxygen in the body
To analyze blood, need to do phlebotomy - process of making a puncture in a vein with a needle to extract blood
Usually blood drawn from veins in arm, adults - median cubital vein (antecubital) found on the inside of the elbow
Extremely large vessel, easy to see and feel → easier blood draw for medical professional
Phlebotomist - trained to draw blood from patients who require testing as well as blood donors
Can work in hospitals, doctor’s offices, Clinical labs, other community health centers
Blood-Borne Pathogens - infectious agents that can be carried by human blood
Blood samples taken to labs for testing; many tests can be run to assess general health
Most routine blood work assesses overall composition of blood
Cholesterol testing → risk factor for heart disease
Results of testing may indicate needing more specialized testing
Complete Blood Count (CBC) - relative count of each type of cell/cell fragments in sample
Levels of each type of cell/cell fragment outside of normal range can indicate injury or disease
White Blood Cells (WBC) - five types of cells that the body uses to fight infection and injury and maintain our health
Red Blood Cells (RBS) - the cells that transport oxygen around the body
Hemoglobin (HB/Hgb) - the oxygen-carrying protein in red blood cells
Hematocrit (HTC) - the proportion of red blood cells to plasma - the fluid component in blood
Platelets - the cell fragments that assist with clotting
CBC Report contains the particular range of normal values
Anemia - condition that occurs when amount of hemoglobin in a person’s blood drops below the normal range
If values in CBC out of normal range, additional testing may be completed, which can involve looking at blood sample under a microscope
Changes to normal distribution of cell types in blood can indicate problem
How cells look under microscope can provide additional clues for diagnosis
Leukemia - type of cancer caused by production of abnormal white blood cells (leukemia blasts)
Hematologist - doctor that specializes in research, diagnosis, treatment, and prevention of blood disorders
May work in hospitals, labs, clinics, or blood banks
A doctor may order a cholesterol test as part of routine exam or when patient has specific risk factors - anything that increases person’s chance for disease/injury
Cholesterol - waxy substance naturally produced in liver and absorbed from food as it passes through intestines
Cholesterol must be transported to all cells in the body
Key component in structure of cell membranes and used to make essential molecules (hormones and vitamins)
Carried by the blood stream
Lipoprotein - biomolecule made of a combination of lipid or fat, and protein
LDL - lipoprotein responsible for transporting cholesterol to the cells
Foods high in saturated fat - fats typically solid at room temperature - can cause increase in LDL cholesterol
Foods with unsaturated fats help cholesterol balance by decreasing LDL and increasing HDL
HDL - lipoprotein responsible for removing excess cholesterol from blood stream and transporting it to the liver
Body needs to maintain specific balance of both
Too much cholesterol in blood (particularly LDL) can cause build-up of plaque - fatty substance that builds up inside arteries
HDL helps get rid of excess LDL that can cause blockages
Balance of LDL and HDL keeps circulating lipids from becoming trapped inside our blood vessels
Cholesterol Test - when ordered, recommended to fast 8-12 hours before blood collection → food consumption can impact test results
Patient receives information about level of LDL, level of HDL, and total cholesterol level
Results of each of these 3 numbers provides a measure of risk
Metabolism - all the chemical reactions and operations going on inside the body
Other substances found in blood can give professionals important information about its status
Requires nutrients to fuel of body’s function and produces wastes that need to be properly processed
Monitoring specific substances in blood provides info about these reactions
Abnormal metabolic panel results may indicate diabetes, problems with kidneys, or other issues with hormones - chemical signals that help communicate info
The following substances monitored in a Basic Metabolic Panel:
Glucose - simple sugar that body uses for energy; high levels may increase risk for diabetes
Electrolytes - minerals found in blood, urine, and other tissues
Sodium, calcium, potassium, and chloride help keep water balance, move nutrients into cells and wastes out, ensure functioning of nerves, brain, muscles, and heart
Blood Urea Nitrogen (BUN) & Creatinine - waste products filtered out of body by kidneys; levels give indication of how well kidneys are functioning
Biomarkers - signals in blood that may indicate risk for disease or presence of disease or injury
Referrals - written order from primary care doctor for patient to see specialist or get particular medical service (physical therapy after injury as an example)