Both, peripheral resistance decreases and cardiac output increases.
total peripheral resistance will decrease because of vaso dilation of local arterioles that are supplying the active muscles i.e,skeletal muscles. and blood pressure will increase for two reasons: increased cardiac output resulting from increased pumping activity of heart. because of vasoconstriction of arterioles every where else in the body
The major site that determines peripheral resistance is the arterioles. These small-diameter blood vessels can constrict or dilate to regulate blood flow and pressure throughout the circulatory system. Their ability to change diameter significantly influences total peripheral resistance, impacting overall cardiovascular function.
Peripheral resistance is the force against blood flow. In most cases, an increase in peripheral resistance would be caused by an increase in vasoconstriction, which would decrease blood flow. Other factors can influence vasoconstriction, such as circulating angiotensin II levels, cortisol levels, drugs such as cocaine and other adrenergic agonists, blood volume, atherosclerosis, emboli, renal diseases and increased intra-cranial pressure. An increase in blood pressure will also be caused by vasoconstriction and the mentioned factors.
A change in cardiac output without any change in the heart rate, pulmonary artery wedge pressure (PAWP = equated to preload) or systemic vascular resistance (SVR = afterload) would have to be due to a change in the contractility of the heart. Cardiac output (CO) is roughly equal to stroke volume x heart rate. Stroke volume is related to preload, contractility, and afterload. As you can see, the only variables you have not controlled for is cardiac contractility.
Vessel diameter can change quickly through casconconstruction or vasodilation. Most of the peripheral resistance occurs in arterioles (the small vessels of the arterial system). When these smooth muscles contract or relaz, peripheral resistance is either increased or decreased.Source: Modern Anatomy & Physiology by Ateegh Al-Arabi
An increased hematocrit indicates a higher ratio of RBC's in the blood. Any increase in cellular elements, whether WBC's, RBC's or platelets, will act to essentially mechanically "thicken" the blood viscosity, sort of like using a heavier grade oil in your car. Increased blood viscosity will increase peripheral resistance, as it becomes harder for the heart to circulate the thicker blood, especially in the capillaries.
respiratory system change with more exercise because it is related to our cardiovascular and respiratory system.when we do exercise our heart rate increases cardiac output increases and oxygen is more utilizing and more energy is required.These all cause effect on respiratory system
A cardiac cycle is the complete sequence to make one complete contraction. Factors that influence the cardiac cycle include the increase and decrease in heart rate, change of posture, parasympathetic nervous system activity and sympathetic nervous system activity.
A resistance that doesn't change.
you are asking about "cardiac output," which is the amount of blood that gets pumped out of the heart, usually given in liters per minute (remember that since the circulatory system is a closed loop, volume of blood pumped out must equal blood coming back to the heart, assuming you are not actively bleeding). Cardiac output in a normal adult is 5-6 L/min at rest, but can increase to 25 L/min or more during strenuous exercise. Cardiac output (CO) is equal to the Stroke Volume (SV, or the volume of blood pumped with each heart beat) times the heart rate (number of beats per minute). If you have taken physics, you should be familiar with Ohm's law: V=IR. There is also a correlating equation for the circulatory system, which is Mean Arterial Blood Pressure = Cardiac Output times Systemic Vascular Resistance, or MAP = CO x SVR. You can think of MAP as the voltage, CO as the current, and SVR as resistance. This equations relates your cardiac output to your blood pressure and your vascular resistance (how clamped down or open your blood vessels are). Your body is set up to try to maintain a constant blood pressure by adjusting the vascular resistance or cardiac output (which in turn is dependent on stroke volume and heart rate). One good example is active exercise: the blood vessels going to your muscles open up to allow for increased blood flow, which decreases overall vascular resistance. According to the relation above, decreased SVR with no change in CO will cause your blood pressure to drop - enough of a drop in blood pressure will cause you to pass out. Therefore, your cardiac output MUST increase to maintain a constant blood pressure. During exercise, I'm sure you have noticed that both your heart rate increases, but your heart is also beating more strongly, which pumps more blood with each beat.
Dumbbells provide fixed resistance. Fixed resistance provides a constant amount of resistance throughout the full range of motion (ROM) of a strength training exercise. This means that the amount of resistance/weight you are lifting does not change during the movement. For example, during a 10-pound curl, you are lifting 10 pounds throughout the motion. Fixed resistance helps to strengthen all the major muscle groups in the body.
Changing the potential difference in a circuit does not change the resistance. Rather, it changes the current.