Physiology and Basic Medical Terminology
This domain links how the body maintains stability with the language you use to describe it. Expect questions on normal values, homeostasis and word-building.
Physiology essentials
Homeostasis is the maintenance of a stable internal environment through negative feedback. Transport across membranes occurs by diffusion, osmosis, facilitated diffusion, active transport and filtration. The cardiac cycle gives a normal resting heart rate of 60–100/min and blood pressure of about 120/80 mmHg; respiratory rate is 12–20/min and SpO2 is 95% or above. Body temperature is about 37 °C (98.6 °F).
Values worth memorising
- Haemoglobin: 13–17 g/dL (men), 12–15 g/dL (women)
- RBC: 4.5–5.5 million/µL; WBC: 4,000–11,000/µL; platelets: 1.5–4.5 lakh/µL
- Fasting blood glucose: 70–110 mg/dL
Word building
A medical term is prefix + root + suffix, with the combining vowel (usually o) joining root to suffix. Common prefixes: tachy- (fast), brady- (slow), hyper- (excess), hypo- (deficient), dys- (difficult), poly- (many), a-/an- (without), hemi- (half), sub- (under), inter- (between). Common suffixes: -itis (inflammation), -ectomy (surgical removal), -otomy (incision into), -ostomy (opening), -ology (study of), -pathy (disease), -aemia (blood condition), -uria (urine condition), -algia (pain), -megaly (enlargement), -scopy (visual examination), -plasty (repair).
Worked example
Break down hyperglycaemia: hyper = excess, glyc = sugar, -aemia = blood condition, so excess sugar in the blood. Now gastrectomy: gastr = stomach, -ectomy = removal, so surgical removal of the stomach.
Traps that cost marks
Mixing -ectomy (removal), -otomy (incision) and -ostomy (opening). Writing -aemia as -emia inconsistently. Assuming brady- means painful rather than slow.