Exam 2 Flashcards
What are the primary functions of the cardiovascular system?
delivery of oxygen (O2) and energy substrates (nutrients)
* removal of CO2 and other metabolic waste products
* transportation of hormones and other molecules
* thermoregulation
* body fluid balance
* maintain acid-base balance
What is the blood flow direction in the cardiovascular system?
The heart is unidirectional with four valves that prevent backflow.
What are the two sides of the heart responsible for?
Left side = systemic circulation
* Right side = pulmonary circulation
What do arteries do?
carry blood away from the heart
What is the function of capillaries?
deliver oxygen to metabolizing tissues and CO2 to the lungs
What do veins do?
carry blood back to the heart
What is the role of the right atrium?
accepts deoxygenated blood from the coronary sinus, superior vena cava, and inferior vena cava
What prevents backflow into the right atrium during ventricular contraction?
Right atrioventricular valve
What happens during right ventricle contraction?
sends deoxygenated blood to the lungs
What does the left atrium do?
accepts O2-rich blood from the pulmonary veins
What occurs when the left ventricle contracts?
sends blood to the body systems through the aortic semilunar valve
What are the phases of cardiac function?
Contraction phase (systole)
* Relaxation phase (diastole)
What is systolic blood pressure?
pressure when the heart contracts
What is diastolic blood pressure?
pressure when the heart relaxes
How is heart rate defined?
beats per minute
What is stroke volume?
mL of blood ejected with each beat
What does ejection fraction represent?
the % of ventricular volume ejected with each heartbeat
What is the normal ejection fraction range?
55-60%
How is cardiac output calculated?
Cardiac Output (CO, or Q) = HR X SV
What is the average blood volume in an adult?
5L
What happens to blood volume after starting exercise?
expands within 10 days
What are the components of blood volume?
Plasma 55% (primarily water)
* Formed elements 45% (primarily erythrocytes/red blood cells)
What is the average resting heart rate for adults?
70-72 bpm
What is the equation for predicting maximal heart rate?
MHR = 220 - age
What does steady state heart rate indicate?
the plateau in HR reached during a set workload
What is cardiovascular drift?
alterations in cardiovascular variables over time with exercise
What happens to stroke volume during exercise?
increases with work, then levels off
What are two primary reasons for increased stroke volume during exercise?
- Ventricles enlarge (distensibility)
- Ventricles contract more powerfully (increase in EF)
What is the typical blood pressure response to exercise?
Systolic BP increases linearly with exercise; Diastolic BP usually does not change
How is blood flow distributed at rest compared to exercise?
Rest: 60% viscera; Exercise: muscle (60-80%)
What causes vasodilation during exercise?
increased blood flow to skeletal muscles
What is hemoglobin’s role in red blood cells?
binds O2 and carries it in the blood
What is the oxygen carrying capacity of blood?
20mL O2 for 100 mL blood
What happens to blood distribution during exercise?
increased blood flow to muscles and decreased to viscera
