Cardiovascular System & Exercise Flashcards
What is the role of the heart
it provides the force to propel blood throughout the vascular circuit
What is the role of semilunar valves
they prevent regurgitation between ventricular contractions
Where is the tricuspid valve found
between the right atrium and ventricle
Where is the mitral/bicuspid valve found
between the left atrium and ventricle
What are the functions of the chambers of the right heart pump
- Receive deoxygenated blood returning from all parts of the body
- Pump blood to the lungs for aeration via the pulmonary circulation
What are the functions of the chambers of the left heart pump
- Receive oxygenated blood from the lungs
- Pump blood into the aorta for distribution throughout the body via the systemic circulation
What are the roles of arteries
- circulates oxygenated blood from the heart to the body
- arteriole walls contain circular layers of smooth muscle that either constrict or relax to regulate peripheral blood flow
What is the roles of capillaries
- gases, nutrients, and waste products rapidly transfer across the thin, porous, capillary walls
- velocity progressively decreases as blood moves toward and into the capillaries
What are the roles of veins
- they empty less oxygenated (deoxygenated) blood from the body back into the heart
- flap like valves are spaced within the vein to permit one way blood flow back to the heart
- the venous system acts as an active blood reservoir to either retard or enhanced blood flow to the systemic circulation
Define blood pressure
it is the amount of pressure that blood puts on the walls of a vessel
Define systolic blood pressure
highest arterial pressure measured after left ventricular contraction
Define diastolic blood pressure
lowest arterial pressure measured during left ventricular relaxation
What happens to systolic and diastolic blood pressure during rhythmic exercise
Systolic - increases in the first few minutes and then levels off
Diastolic - remains relatedly unchanged
How does resistance exercise increase blood pressure dramatically
there are vessels that run through the muscles and when the muscles contract they push on the vessel therefore restricting them causing a decrease in the vessels diameter for the blood to pass through
Why does blood pressure increase more with upper body exercises than lower body exercises
upper body exercises involve a lot more muscles than lower body exercises do
Why does blood pressure lower after a bout of exercise/during recovery
- repair tissues
- blood is pooling/blood reserve for tissues and muscles
- elasticity of the vessels
- vasodilation/parasympathetic system
Describe coronary circulation
Right coronary artery - supplies predominantly the right atrium and ventricle
Left coronary artery - supplies the left atrium and ventricle, and a small portion of the right ventricle
How much oxygen is extracted by the myocardium (heart) during rest from the blood flowing in the coronary vessels
70% - 80%
How does the body meet myocardial oxygen demands during exercise
- coronary blood flow increases which means the heart is pumping faster
- during vigorous exercise, coronary blood flow increases 4-6 times above the resting level
What is rate-pressure product, what mechanical factors determine myocardial oxygen uptake, and what is the equation to calculate it
Rate-Pressure Product (RPP): provides a convenient estimate of myocardial workload
Mechanical Factors: tension development within the myocardium, myocardial contractility, and heart rate (HR)
Equation: RPP = SBP(systolic blood pressure) x HR
How does the heart get it’s energy supply
- relies almost exclusively on energy released from aerobic reactions
- glucose, fatty acids, and lactate formed from glycolysis in skeletal muscle all provide the energy for myocardial functioning
What is the order of electrical circulation/intrinsic heart rate regulation through the heart
Sinoatrial (SA) node –> Atrioventricular (AV) node –> AV bundle/bundle of his –> Purkinje fibers
What does the SA node, AV node, and Purkinje fibers do
SA node - spontaneously depolarizes and repolarizes to provide an “innate” stimulus to the heart
AV node - delays the impulse ~ 0.10 seconds to provide sufficient time for the atria to contract and force blood into the ventricles
Purkinje fibers - speed the impulse rapidly through the ventricles
How does the sympathetic and parasympathetic systems influence heart rate regulation extrinsically
Sympathetic - releases catecholamines epinephrine and norepinephrine and leads to tachycardia
Parasympathetic - releases acetylcholine and leads to bradycardia
How does cortical influence heart rate regulation extrinsically
- it produces an anticipatory heart rate
- experts its effect during exercise, at rest, and in the immediate pre-exercise period
Define extrasystoles
extra beats
Define premature atrial contraction (PAC)
- parts of the atria become prematurely electrically active and depolarize spontaneously prior to SA node excitation
- linked PAC’s can create atrial fibrillation (A Fib)
Define premature ventricular contraction (PVC)
- premature excitation of ventricles
- can create ventricular fibrillation (V Fib)
Equation for blood flow regulation
Flow = Pressure / Resistance
What factors determine resistance to blood flow
- viscosity or blood thickness
- length of conducting tube
- radius of blood vessel
What are local factors of blood flow regulation that enhance regional blood flow
- local increases in temperature
- carbon dioxide
- acidity
- adenosine
- nitric oxide
- magnesium and potassium ions
What are neural factors of blood flow regulation
Central vascular control via sympathetic and parasympathetic portions of the autonomic nervous system (ANS) overrides vasoregulation afforded by local factors
What are hormonal factors of blood flow regulation
With sympathetic activation, adrenal glands release epinephrine and norepinephrine to cause a general constrictor response except in blood vessels of the heart and skeletal muscles
Equation for cardiac output
Cardiac Output = Heart Rate x Stroke Volume
What are the physiologic mechanisms that increase stroke volume during exercise
- enhanced cardiac filling in diastole followed by a more forceful systolic contraction
- neurohormonal influence causes normal ventricular filling with a subsequent forceful ejection and emptying during systole
- training adaptations can expand blood volume and reduce resistance to blood flow in peripheral tissues
Define preload
greater ventricular filling in diastole during the cardiac cycle from an increase in venous return
Define afterload
resistance to flow from increased systolic pressure
Define cardiovascular drift
a decrease in stroke volume causing a dramatic increase in heart rate meanwhile keeping cardiac output the same during prolonged steady-rate exercise (>20 min)
What can cause cardiovascular drift
dehydration
How could you monitor intensity during exercise
- rate of perceived exertion (RPE)
- heart rate (HR) most reliable
- VO2 max
Who’s heart rate would increase to a steady state the quickest (trained/untrained person)
a trained person
Define aerobic capacity
the amount of oxygen that you can utilize
Why do females have larger cardiac output for sub maximal oxygen consumption
males have more hemoglobin (O2 carrying cells)
How do children’s cardiac output compare to adults for sub maximal exercise O2 consumption
children have smaller cardiac output due to having smaller stroke volumes
Equation for VO2 max
VO2 max = Max cardiac output x Max a-vO2 difference
What is a-vO2 difference
it’s the difference between the amount of O2 in the arteries compared to the veins
Why does a-vO2 difference widen during exercise
more oxygen is being absorbed by the organs and muscles to then use for energy during exercise (harder the exercise the more energy required)
At maximal power does the upper extremities or the lower extremities require more oxygen uptake
the lower extremities require more O2 uptake during maximal exercises
At sub maximal power does upper extremities or lower extremities require more oxygen uptake
upper extremities require more O2 uptake during sub maximal exercise
