circulatory_system_m1_l1

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

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%