Physical responses and adaptations of human body to exercise Martin Jančík

Circulatory system Arteries - big vessels; carries oxygenated blood to organs Veins – smaller vessels; carry deoxygenated blood from organs back to heart Pulmonary circulation Systemic circulation

Pulmonary circulation

Heart structure

Cardiac cycle

Animation

Changes in cardiovascular system during stress Cardiac output (Q) Q = stroke volume * heart rate →total volume of blood pumped per min Blood flow during resting conditions only 20% of Q goes to skeletal muscles During phys. stress up to 80% More Q goes also to skin→reducing temperature Blood pressure Increased systolic but not diastolic pressure From around 90 up to mm Hg (torr)

Changes in respiratory system during stress Pulmonary ventilation increases almost immediately, largely through stimulation of the respiratory centers in the brain stem When working out closed capilares open Heart must be constantly supplied by oxygen Pulmonary ventilation (the total volume of gas per minute inspired or expired) Ordinary untrained people – 10 l/min during resting conditions and up to 100 l/min during max. physical stress Trained people – up to 200 l/min during max. phys. stress

Adaptations Cardiovascular system adaptations Increased stroke volume and enlargement of cardiac muscle → lower HR Respiratory system adaptations Increased effort and power of respiratory muscles Increased pulmonary ventilation and vital capacity (maximum amount of air a person can expel from the lungs after a maximum inhalation) Better oxygen income to cardiovascular system and its better usage Muscular and skeletal system adaptations Bones –increased amount of mineral substances Muscles –increased total strength, better coordination, hypertrophy of muscular fibres (increased muscle volume)

Interactive part Name the parts of the heart with : Right Atrium Left Atrium Left Ventricle Right Ventricle Aorta

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