# Anatomy and Physiology Cheat Sheet ## Basic Definitions - Anatomy: Study of structure - Physiology: Study of function - Pathology: Study of disease - Biochemistry: Study of chemical processes ## Levels of Organisation - Chemical → Cellular → Tissue → Organ → Organ System → Organism - Example: Atoms → Cells → Tissues → Heart → Cardiovascular System → Human ## Homeostasis - Definition: Stable internal environment - Negative feedback: Reverses change - Example: Body heat regulation via sweating ## Anatomical Terminology - Superior: Above - Inferior: Below - Anterior: Front - Posterior: Back - Medial: Towards midline - Lateral: Away from midline ## Major Body Systems - Cardiovascular: Transports blood - Respiratory: Gas exchange - Digestive: Nutrient absorption - Nervous: Communication/control - Endocrine: Hormonal regulation ## Four Major Tissue Types - Epithelial: Covers/lines - Connective: Supports/protects - Muscle: Movement - Nervous: Signals ## Cardiovascular System - Heart: 4 chambers - Blood flow: Body → Right heart → Lungs → Left heart → Body - Valves: Prevent backflow - SA node: Pacemaker - AV node: Signal delay ## Blood Components - RBCs: Oxygen transport - WBCs: Immune defense - Platelets: Clotting - Plasma: Transport medium ## Respiratory System - Pathway: Nose → Pharynx → Larynx → Trachea → Bronchi → Alveoli - Gas exchange: Alveoli - Diaphragm: Inhale = down, Exhale = up - Regulation: CO₂ levels ## Common Conditions - Hypertension: High blood pressure - Atherosclerosis: Plaque in arteries - Anaemia: Low oxygen capacity - Asthma: Narrowed airways - Pneumonia: Lung infection