Sports Science

Systems and Response

  • Hierarchy of Organization:

    • Cell → smallest unit, performs functions of life (nutrition, metabolism, etc.)

    • Tissue → group of specialized cells

    • Organ → multiple tissues, specific function

    • Organ system → group of organs

    • Organism → entire living being

🫁 Ventilatory System

  • Pathway of Air:

    • Nostrils → Nasal/Oral cavity → Pharynx → Larynx → Trachea → Bronchi → Bronchioles → Alveoli

  • Ventilation:

    • Inhalation (Active):

      • External intercostals + diaphragm contract → chest expands → pressure ↓ → air in

    • Exhalation (Passive at rest):

      • Muscles relax → chest contracts → pressure ↑ → air out

    • During exercise:

      • Internal intercostals + abdominals contract

  • Measurements:

    • Ventilation rate = breaths/min

    • Tidal volume = air in/out at rest

    • Vital capacity = max in and out

    • Residual volume = air left after exhale

    • Peak flow = max air expelled forcefully

❤ Cardiovascular System

  • Pathway:

    • Pulmonary loop: Right atrium → Right ventricle → Pulmonary artery → Lungs → Pulmonary vein

    • Systemic loop: Left atrium → Left ventricle → Aorta → Body → Vena cava

  • Heart Anatomy & Function:

    • Cardiac cycle:

      • Atria fill → SA node fires → Atria contract → AV node → Ventricles contract

      • "Lub" = AV valves close; "Dub" = Semilunar valves close

    • Systole = contraction, Diastole = relaxation

  • Electrical conduction:

    • SA node → AV node → bundle of His → Purkinje fibers

  • Blood Vessels:

    • Arteries: thick, high pressure, no valves

    • Capillaries: thin, material exchange

    • Veins: thin walls, low pressure, valves prevent backflow

🩸 Blood

  • Components:

    • Plasma, RBCs, WBCs, platelets

  • Functions:

    • Transport nutrients, gases, heat

🔄 Diffusion & Osmosis

  • Diffusion:

    • Movement of particles from high → low concentration until equilibrium

    • Types: Simple, Facilitated (with protein channels)

  • Gas Exchange: In alveoli via diffusion (O₂ in, CO₂ out)

  • Osmosis:

    • Movement of water from low → high solute concentration

    • Hypertonic: more solute

    • Isotonic: equal

    • Hypotonic: less solute