Overview
This lecture provides an overview of human anatomy and physiology, focusing on body systems, anatomical terminology, life support chain elements, and basic medical terminology for EMTs.
Anatomical Position & Directional Terms
- Normal anatomical position: standing, facing forward, palms forward; all references are from this position.
- Sagittal (medial/lateral) planes divide right and left; midline is the central reference line.
- Medial means closer to midline; lateral means further from midline.
- Proximal is closer to the torso; distal is further from the torso.
- Bilateral refers to structures on both sides; unilateral on one side.
- Transverse (axial) planes divide the body into top and bottom; superior is above, inferior is below.
- Anterior/ventral = front; posterior/dorsal = back.
- Quadrants of the abdomen: RUQ, RLQ, LUQ, LLQ.
- Palmar = palm, plantar = sole of foot.
Patient Positions
- Supine: lying on back; prone: lying on stomach; lateral recumbent: on side (recovery position).
- Fowler’s: sitting up; Semi-Fowler’s: semi-sitting; Trendelenburg/Shock: feet elevated.
Skeletal & Muscular Systems
- Skeletal system: 206 bones; provides structure, protection, movement, blood cell production, and mineral storage.
- Major bones: skull, spine (cervical, thoracic, lumbar, sacral, coccygeal), thorax, pelvis, femur, tibia, fibula, patella, clavicle, scapula, humerus, radius, ulna.
- Joints enable movement; types include hinge and ball-and-socket.
- Muscular system includes skeletal (voluntary), smooth (involuntary), and cardiac (heart) muscles.
- Muscles produce movement, protect organs, generate heat.
Respiratory System
- Major structures: nasal cavity, oral cavity, pharynx (naso-, oro-, laryngo-), epiglottis, larynx, trachea, bronchi, bronchioles, alveoli.
- Functions: ventilation (moving air), respiration (gas exchange), acid-base balance.
- Pediatric airway differs: smaller, proportionally larger tongue, less rigid cartilage.
Circulatory System
- Heart: right/left atrium and ventricle, separated by valves.
- Blood flow: deoxygenated blood enters right heart, goes to lungs; oxygenated returns to left heart, pumped to body.
- Main arteries: aorta, pulmonary, carotid, brachial, radial, femoral, posterior tibial, dorsalis pedis.
- Capillaries exchange gases with cells; veins return blood to heart via vena cava.
- Blood components: red cells (carry O2/CO2), white cells (immunity), platelets (clotting), plasma (fluid).
Nervous System
- Central nervous system: brain and spinal cord; peripheral nervous system: sensory/motor nerves.
- Autonomic control: sympathetic ("fight or flight") and parasympathetic ("feed or breed") systems.
- Functions: consciousness, sensation, motor control.
Integumentary System (Skin)
- Skin layers: epidermis (outer), dermis (middle), subcutaneous (inner).
- Functions: protection from infection, temperature regulation, sensation.
Other Body Systems
- Digestive: mouth, esophagus, stomach, intestines, liver, gallbladder, pancreas; absorbs nutrients, removes waste.
- Endocrine: glands like pancreas, adrenal, pituitary; regulate functions via hormones.
- Renal/urinary: kidneys, ureters, bladder, urethra; filter blood, regulate fluids/electrolytes, excrete waste.
- Reproductive: structures differ by sex; function is reproduction and hormone production.
Life Support Chain
- Elements: oxygenation, perfusion, and cellular environment.
- Adequate airway, ventilation, blood volume, and functioning heart are critical for life.
- Cells require oxygen for aerobic metabolism (efficient ATP); without oxygen, anaerobic metabolism leads to lactic acid and cell death.
Medical Terminology Basics
- Medical terms are built from prefixes, root words, and suffixes.
- Prefixes modify meaning (hyper- = high, hypo- = low, tachy- = fast, brady- = slow, etc.).
- Suffixes indicate condition or field (-itis = inflammation, -ology = study of).
- Roots specify body parts or systems (cardi- = heart, neur- = nerve, etc.).
- Use plain language with patients; avoid non-standard abbreviations.
Key Terms & Definitions
- Anatomy — study of body structure.
- Physiology — study of body function.
- Perfusion — blood flow through capillaries delivering oxygen/nutrients.
- Ventilation — movement of air into and out of lungs.
- Respiration — gas exchange between blood and cells.
- Aerobic metabolism — cell energy production using oxygen.
- Anaerobic metabolism — cell energy production without oxygen, produces lactic acid.
- Superior/inferior — above/below reference point.
- Medial/lateral — toward/away from midline.
- Proximal/distal — closer/further from torso.
- Supine/prone — lying on back/stomach.
- Sympathetic/parasympathetic — "fight or flight" / "rest and digest" systems.
Action Items / Next Steps
- Review body systems and anatomical terms.
- Practice identifying directional terms on diagrams.
- Learn and practice common medical terminology.
- Prepare for upcoming modules focusing on each system in detail.