Master Basic Medical Sciences
for SMLE

Core Concepts

Basic Medical Sciences form the bedrock of clinical practice, integrating knowledge from multiple disciplines to understand health and disease.

• Anatomy & Histology: Study of body structures (gross, microscopic). Focus on functional anatomy, regional anatomy (e.g., neurovasculature of specific organs, anatomical triangles/spaces with clinical significance), and histology of major tissues/organs (epithelium, connective tissue, muscle, nerve; unique features of liver, kidney, lung).
• Physiology: Mechanisms of body function and homeostasis. Key systems: cardiovascular (cardiac cycle, blood pressure regulation), respiratory (gas exchange, lung volumes), renal (filtration, reabsorption, acid-base balance), endocrine (hormone axes, feedback loops), nervous (neurotransmission, sensory/motor pathways), gastrointestinal (digestion, absorption), musculoskeletal.
• Biochemistry: Molecular basis of life. Metabolism (glycolysis, TCA cycle, oxidative phosphorylation, lipid synthesis/breakdown, amino acid metabolism), enzyme kinetics, protein structure/function, nucleic acid structure/replication/transcription/translation, molecular genetics (gene expression, mutations).
• Pharmacology: Principles of drug action (Pharmacodynamics - MOA, receptor interactions, dose-response) and fate (Pharmacokinetics - Absorption, Distribution, Metabolism, Excretion). Drug classes, adverse effects, contraindications, drug interactions.
• Pathology: Study of disease. General pathology covers cellular injury/adaptation (atrophy, hypertrophy, hyperplasia, metaplasia, dysplasia, necrosis, apoptosis), inflammation (acute/chronic, mediators), wound healing, neoplasia (benign vs. malignant, metastasis, oncogenes, tumor suppressor genes). Systemic pathology applies these principles to specific organ diseases.
• Microbiology: Study of microorganisms (bacteria, viruses, fungi, parasites) and their role in disease. Classification, structure, replication, pathogenesis, common pathogens, mechanisms of antimicrobial action and resistance, sterilization/disinfection.
• Immunology: Study of the immune system. Innate vs. adaptive immunity, immune cells (lymphocytes, phagocytes), MHC molecules, antigen presentation, antibody production, hypersensitivity reactions (Types I-IV), autoimmunity, immunodeficiency.
• Genetics: Inheritance patterns (autosomal dominant/recessive, X-linked), chromosomal abnormalities (aneuploidy, translocations), genetic mutations, basic Mendelian and non-Mendelian disorders, molecular diagnostic techniques.

Clinical Presentation

• **Anatomical Defects/Injuries:** Nerve palsies (motor/sensory deficits), vascular compromise (ischemia, infarction), organ displacement/herniation, fractures, ligamentous tears.
• **Physiological Dysregulation:** Hypertension, arrhythmias, respiratory failure (hypoxia, hypercapnia), electrolyte imbalances, acid-base disorders, hormonal imbalances (e.g., diabetes, thyroid dysfunction).
• **Metabolic Disorders:** Accumulation of toxic substrates (e.g., inborn errors of metabolism), energy deficiencies (e.g., mitochondrial disorders), often presenting with multi-organ dysfunction, developmental delay.
• **Infections:** Fever, localized inflammation (redness, swelling, pain, heat), systemic symptoms (sepsis), specific organ involvement (pneumonia, meningitis, UTIs).
• **Inflammation/Autoimmunity:** Chronic pain, swelling, tissue damage, systemic symptoms (fatigue, fever), organ-specific dysfunction (arthritis, lupus).
• **Neoplasia:** Unexplained weight loss, new masses, abnormal bleeding, pain, obstruction, paraneoplastic syndromes.
• **Genetic Conditions:** Dysmorphic features, developmental delay, organ malformations, characteristic disease patterns inherited across generations.
• **Drug Reactions:** Rashes, anaphylaxis, organ toxicity (hepatotoxicity, nephrotoxicity), neurological effects, hematological changes.

Diagnosis (Gold Standard)

Diagnosis often integrates basic science principles:

• **Lab Tests:** Biochemical markers (enzymes, metabolites, electrolytes, hormones), genetic testing (PCR, sequencing, karyotyping), immunological assays (ELISA for antibodies/antigens, flow cytometry for cell phenotyping), microbiology cultures/PCR for pathogens.
• **Imaging:** X-ray, CT, MRI, Ultrasound to visualize anatomical structures and pathological changes (tumors, inflammation, fractures).
• **Biopsy & Histopathology:** Definitive diagnosis of cellular and tissue abnormalities (e.g., cancer, specific inflammatory patterns, organ damage).
• **Physiological Studies:** ECG (cardiac function), spirometry (lung function), nerve conduction studies/EMG (neuromuscular function).

Management (First Line)

Management directly applies basic science knowledge to restore health:

• **Pharmacological:** Targeting specific receptors (agonists/antagonists), inhibiting enzymes, antimicrobial agents (targeting bacterial cell wall, protein synthesis, nucleic acids), immunosuppressants, hormonal replacement.
• **Physiological Support:** Fluid and electrolyte resuscitation, oxygen therapy, ventilatory support, blood transfusions.
• **Surgical Intervention:** Anatomical correction, tumor removal, repair of injuries.
• **Immunotherapy:** Monoclonal antibodies, vaccines, allergen desensitization.
• **Genetic Therapies/Counseling:** Enzyme replacement, gene therapy, lifestyle modifications based on genetic predisposition, reproductive counseling.

Exam Red Flags