Circulation and Immunity

Cardiovascular System
 The system consisting of the heart, blood vessels and blood that circulates through the body.

Cardiovascular System
 The human circulatory system performs four key functions.
 It transports and delivers oxygen and nutrients (e.g. minerals, vitamins, and glucose) to the body’s cells in exchange for carbon dioxide and wastes.
 It transports chemical messengers, such as hormones throughout the body.
 It distributes heat
 It defends against disease

Cardiac Output
 Cardiac Output is the volume of blood pumped by the heart in one minute, which is equal to the product of stroke volume and heart rate.

Average Values
 The average human male pumps out 70mL of blood per beat (60 mL for females) with an average resting heart rate is around 72 beats per minute.

Example Question
 A typical human male has a stroke volume of 70 mL per beat and a resting heart rate of
72 beats per minute.
 A. Calculate the cardiac out put. Express your answer in litres per minute.
 B. Calculate the volume of blood that would be pumped in one day based upon the cardiac output.

Example Question
 A typical human male has a stroke volume of 70 mL per beat and a resting heart rate of
72 beats per minute.
 A. Calculate the cardiac out put. Express your answer in litres per minute.
 Solution.
 Stroke volume = 70 mL/beat
 70 mL x 1/1000mL = 0.070 L/beat

Example Question
 A typical human male has a stroke volume of
70 mL per beat and a resting heart rate of 72 beats per minute.
 Solution.
 Cardiac output (stroke volume)x(heart rate)
 =(0.070 L/beat)x 72 (beats/min) = 5.04 L/min
 In one day 5.04 L/min x 1440 min/day
 = 7257.6 L = 7.3 x 10 3 L/day

Heart Diagram

Heart Diagram

Blood Flow

Blood Flow

Blood Flow

Blood Flow

Heart Beat
 Diastole the phase of the heart’s cycle where a chamber of the heart, either an atrium or a ventricle, relaxes and fills with blood. Semilunar valves closed “dub” sound produced
 Systole the phase of the heart’s cycle when the ventricles contract to eject blood from within the chamber. AV vales closed -
“lub” sound produced.

Heart Beat

Factors Affecting Heart Rate
 Emotions ie. Fear anxiety
 External temperature. Hotter = Higher HR
 Activity level.
 Age. Older you get the lower your max HR
 Fitness level.
 Medical conditions.

Target Hear Rate for Exercise
 Your maximum heart rate is approximately
220 - your age.
Target Heat Rates
Personal Health Goal % of Max Heart
Rate
Maintain fitness level 50 - 60%
Increase fat burning of weight loss
60 - 70%
Increase cardiovascular endurance
70 - 80%