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Unformatted text preview: CIRCULATORY AND RESPIRATORY SYSTEMS Homeostasis- maintaining constant internal conditions under changing environmental conditions Organ systems that supply tissues must have reserve capacity: increase or decrease supply when physiological demand changes Supply of oxygen to metabolizing tissues integrated function of circulatory and respiratory systems Circulatory System: Blood cells Erythrocyte Red Blood Cell no nucleus, most numerous oxygen, CO2 transport Leukocyte White Blood Cell; several types: - neutrophil segmented (polymorphic) nucleus, granular appearance phagocytic - lymphocyte large, round nucleus immune functions arteriesaway from heart veins towards heart Circulatory system: paths of blood flow 2 circuits: 4-chambered heart Pulmonary - right side - to lungs and back oxygenation of blood Systemic - left side - to body tissues and back delivery of O2 fluctuation in blood pressure drops with distance from heart pressure damping blood pressure drops with distance from heart Blood pressure - systole vs. diastole - systole - maximum contraction - pressure generation - diastole - relaxation refilling of chambers with venous blood Blood pressure measurement - sphygmomanometer - when pressure on cuff exceeds systolic no blood flow, no sound - between systolic and diastolic blood pulses through artery, produces ticking sound (Korotkoff's sound) - when cuff pressure less than diastolic blood flow is continuous, no sound Increasing cardiac output - reserve capacity 1. increase stroke volume - volume pumped per contraction 2. increase heart rate Blood pressure is affected by: a. amount of heart contraction b. stroke volume c. peripheral resistance - all circulatory routes not open simultaneously - more routes open lower resistance For each individual, measure: 1) Resting pulse, systolic, and diastolic blood pressure 2) Exercise vigorously for 3-5 minutes 3) Take pulse rate, blood pressure immediately following exercise Expected changes: Blood pressure variable among individuals - well-conditioned athletes: decrease blood pressure (esp. systolic) by opening up more blood flow to muscles reduced peripheral resistance - sedentary increased ventricle contraction increase blood pressure Pulse rate generally increased by exercise ; amount varies based on fitness RESPIRATORY RESERVES ability to increase volume of gas exchanged when needed Negative pressure breathers - aspiration mechanism - partial vacuum in lungs by expanding volume of thoracic cavity Amount of expansion increases with demand: 1) low level activity - diaphragm alone 2) moderate levels of activity - intercostal muscles expand, compress rib cage 3) extreme activity - abdominal, trunk muscles move viscera up and down Reserve capacity two ways to increase gas exchange 1) increase tidal volume - volume of gas exchanged per cycle 2) increase breathing rate Tidal volume - increases from rest exertion - increased inhalation inspiratory reserve - increased exhalation expiratory reserve
inspiratory reserve resting tidal volume expirator y reserve maximal tidal volume At maximal exertion, tidal volume = vital capacity - maximum volume of air that can be moved in and out with a single breath Spirometer - measures only expiration volumes; do not inhale 3 measurements: A) inhale normally, then expel as much air as possible into spirometer resting tidal volume + expiratory reserve B) exhale normally, then expel as much air as possible into spirometer expiratory reserve only C) inhale maximally, then expel as much air as possible into spirometer vital capacity = the sum of inspiratory reserve, expiratory reserve, and tidal volume A B = resting tidal volume C A = inspiratory reserve Compare your vital capacity with average: Dubois chart - normal vital capacity for man or woman of given height and weight Look up your weight and height - find surface area of body - multiply x 2 for women, 2.5 for men = expected vital capacity in Liters - calculate % difference from average - your measured vital capacity vs. the expected average Example: - your vital capacity is 4.25L (measured with spirometer) - expected vital capacity is 4.0L (calculated from Dubois chart) % difference = (4.25- 4.0)/ 4.0 x 100 = (0.25/4) x 100 = + 6.25% RESPIRATORY RATE Total volume of gas exchange = tidal volume x frequency of respiration Respiratory minute volume = tidal volume x # of breaths/minute Measure respiratory rate before and after vigorous exercise Resting minute volume resting tidal volume x resting rate Exertion minute volume = vital capacity x after exercise rate TO DO: 1. Blood cell slides. Identify erythrocyte, neutrophil, lymphocyte. 2. Figure 1. Label heart components. 3. Table 1 and 2. Collect BP and heart rate data before and after exercise. 4. Figure 2. Label respiratory system components. 5. Table 3 and 4. Measure respiratory volumes and % deviation from average for 2 individuals. Average of 3 readings for each measured volume. 6. Table 5. Respiratory minute volume, before and after exercise. TO TURN IN NEXT WEEK: 1. Data from Tables 1-5, and paragraph of interpretation of each. What do these numbers tell you about the mechanics or function of the heart and respiratory system? ...
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