Pathology

Definition

Study of structure & functional changes in tissues or organs which cause or are caused by disease

Branches of Pathology

Haematology study of blood i.e. nature, function & diseases of the blood

Histology study of structure, function of body tissues

Immunology study of Immunity & the body’s defense mechanisms

Cytology study of the form & functions of body cells

Biochemistry chemical composition of blood

Microbiology study of microorganisms

Bacteriology study of bacteria

Serology study of serum

Clinical pathology laboratory testing for diagnosis

Surgical pathology

use of surgery to diagnose

Collection of specimens

Aspiration drawing off fluid from a body cavity

Venepuncture puncture of a vein to withdraw blood specimen

Biopsy removal of tissue for examination to establish a diagnosis

Swab a gauze coated stick used to take bacterial specimens

Faecal fat analysing faeces of fat content

ExaminationCulture and sensitivity

growth of microorganisms in special medium to test for specimens reaction to agents e.g. antibiotics

Microscopic appearance

appearance of organisms or tissue under magnification

Blood Count number of blood cells in a given sample of blood

In vitro in a glass – observations made outside of body

Autopsy examination of the body after death

In vivo observation made within the body

Abbreviations

C&S culture & sensitivity Chol cholesterol

MSU mid stream urine BUN blood urea nitrogen

GTT glucose tolerance test U/A urinalysis

LFT liver function test ESR erythrocyte sedimentation rate

LP lumbar puncture FBSL fasting blood sugar level

Pathology results

As an office worker you are required to identify

The patient’s identity i.e name, medical / reference number

The doctor who ordered the test

The type of sample

When the sample was collected

The doctor will sign the report when the results have been reviewed by him/her

HaematologyFull Blood Count (FBC);

Full Blood Examination (FBE)

Determines the amount of red &white blood cells per cubic metre

Haemaglobin (Hb) Measures the protein iron in blood that carries oxygen

Haematocrit (Hct) Measures the packed cell volume of red blood cells

Prothrombin index (PI) measures the amount of time it takes blood to clot

Erythrocyte Sedimentation Rate (ESR)

measures the rate at which red blood cells settle in unclotted blood

Prostate Specific Antigen (PSA) detects presence of specific antigen that increase in prostate cancer

Haematology

Blood group & cross match (Gp & X Match)

Classifies blood then determines compatibility between donor and recipient

Serology Testing Is applied for venereal diseases

e.g. used in AIDS – screens for antigens or antibodies to human immunodeficiency virus (HIV)

Biochemistry

Electrolytes and organic acids are essential for normal body function & metabolism

Examples include sodium, potassium, magnesium, chloride, bicarbonate, calcium

Can be measured in blood serum

Abnormal levels in blood can indicate tissue damage or various disorders

Lipids

Cholesterol

Fatty acids

Triglycerides

NB: Elevated levels can indicate disease, e.g. arteriosclerosis

Biochemistry

Urinalysis examines the chemical properties of urine

Creatinine test measures the amount of creatinine in the urine. If elevated can indicate disturbance in kidney function

Creatinine Clearance

Measures the rate at which kidneys remove creatinine from the blood

Liver Function Teats (LFTs)

abnormal levels indicates damage and presence of liver disease

Cytology

Study of formation, origin, structure, pathology of cells

E.g. Cells can be taken from cerebrospinal fluid lung bronchi, gastric fluid, bone marrow, cervix

Histopathology / histology

Study of tissue to identify presence of disease

Biopsy – small piece of tissue is obtained for examination

Removal of part or all of an organ for examination

Frozen Section – tissue removed at time of surgery & examined under microscope for a quick diagnosis before continuing the surgical procedure

Bacteriology

Study of disease produced by bacteria (microscopic plants & some can produce disease)

Uses specimens of blood, urine, spinal fluid, faeces or any body secretion

Cultures isolate infective organisms which grow

They can then be tested to determine an antibiotic that will destroy the organisms