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

Examination Culture 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

Haematology Full 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