Blood Tests

Comprehensive vocabulary flashcards covering blood test types, phlebotomy steps and equipment, complete blood count parameters, Coulter counter mechanics, red cell distribution width (RDW), cell volume histograms, and pathophysiological mechanisms of anisocytosis.

Blood Testing

A diagnostic procedure performed to check: general health

evaluate organ function (such as kidneys, liver, thyroid, and heart)

identify diseases or disorders

monitor responses to medicines and treatments

assess blood clots

and check hormone levels.

Phlebotomy

, the process of drawing blood from a patient, which commonly utilizes a vacuum collection process.

Phlebotomy Vacuum Process

A 4-step blood drawing procedure:

1) locate veins and apply tourniquet,

2) use a needle to puncture the vein,

3) draw blood,

4) hold vacuum test tubes in a shaft where a double-sided needle punctures the tube to begin vacuum action.

Vacuum Blood Collection System Components

The equipment assembly used in phlebotomy consisting of:

a double-sided needle (with tip, bevel, hub, and rubber sleeve)

a vacuum tube holder (with flange and shaft)

a vacuum tube with a rubber stopper.

Complete Blood Count (CBC)

One of the most common blood tests conducted; it measures

the number, type, and size of red blood cells (RBC)

white blood cells (WBC)

platelets (PLT)

haemoglobin (Hgb) levels

haematocrit (HCT) percentage.

Comprehensive Metabolic Panel (CMP)

A standard blood test listed alongside complete blood count and blood enzyme tests used for evaluating patient health.

Blood Enzyme Tests

Blood tests that check specific enzyme levels to assess heart disease risk and check for a heart attack.

Haemoglobin (Hgb)

An oxygen-carrying protein found inside red blood cells that is routinely measured during a complete blood count.

Haematocrit (HCT)

The percentage ratio of red blood cells to total blood volume.

Coulter Counter

An automated device and method used to obtain a red blood cell profile

(cell count, cell size, volume of Hb, and volume of Hct)

by pumping blood from an electrolyte solution through a glass tube orifice.

Coulter Counter Orifice Principle

A cell-counting mechanism where only one particle enters an orifice at a time, changing electrical resistance and creating a voltage pulse;

the height of the pulse corresponds to particle size, and the pulse count reflects particle quantity.

Discriminators (Coulter Counter)

The upper and lower boundaries set on a Coulter counter processor to filter and categorize cell sizes during analysis.

Femtolitre (fl)

The unit of measurement used on red blood cell histograms to measure cell volume

Microcytic RBC Population

A red blood cell population characterized by smaller-than-normal cell volume, causing the RBC histogram curve to shift toward the left.

Macrocytic RBC Population

A red blood cell population characterized by larger-than-normal cell volume, causing the RBC histogram curve to shift toward the right.

Red Cell Distribution Width (RDW)

A measurement of the difference in size and volume of red blood cells based on the plotted distance between cell sizes, used to indicate conditions such as anaemia, iron or vitamin deficiencies, cardiovascular disease, and aging.

Anisocytosis

A pathological condition defined by a high variation of red blood cell sizes in the blood, indicated by an increased RDW percentage.

Erythropoietin

A hormone produced by the kidneys that stimulates the production of red blood cells.

Anisocytosis Mechanism: Kidney Disease

impaired kidney function reduces erythropoietin production, leading to the generation of smaller red blood cells.

Anisocytosis Mechanism: Nutritional Deficiencies

low iron reduces haemoglobin causing smaller RBCs

vitamin B12 or B9 deficiency impairs RBC formation

low vitamin C prevents iron absorption.

Anisocytosis Mechanism: Oxidative Stress

A mechanism where (ROS) damage the DNA of haematopoietic cells in the bone marrow, resulting in the production of smaller red blood cells.

Anisocytosis Mechanism: Ageing

Loss of haemoglobin makes formation of RBCs hard, creating smaller cells

Anisocytosis Mechanism: Inflammation

prevents body iron stores from being released, hindering haemoglobin formation and causing red blood cells to shrink.