Physioex 5 questions PDF

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Physioex 5 questions...

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Act. 1 Effect of Blood Vessel Radius on Blood Flow Rate 1. Discuss the effect of changing the flow tube radius on flow rate. If flow tube radius is lowered then flow rate is also lower, and if flow tube radius is increased then flow rate is also increased. 2. Describe the effect of changing the flow tube radius on laminar flow of a fluid. How is this critical to our human blood flow? Restricting a blood vessel, lowering radius, means more blood is in contact with the vessel wall and this means there is less laminar flow, free flow, blood cells. The reverse means there is more laminar flow. 3. Why is the relationship exponential between radius and blood flow rate? The relationship is exponential between radius and blood flow rate because the radius is raised to the fourth power in the equation to calculate volume of blood. Act. 2 Effect of Blood Viscosity on Blood Flow Rate 1. List blood components that affect blood viscosity; identify specific situations when viscosity would change (positive and negative). Blood components that would affect blood viscosity are plasma proteins, white blood cells, red blood cells, and platelets. Dehydration would increase viscosity, polycythemia would increase blood viscosity, and anemia would decrease blood viscosity. 2. Discuss the effect that the lab’s viscosity changes had on flow rate. As viscosity was increased the flow rate decreased at a logarithmic pace. Act. 3 Effect of Blood Vessel Length on Blood Flow Rate 1. Discuss the amount of time it takes for a change in blood vessel length and blood vessel radius. When would each occur? Blood vessel length only changes as the body grows in size so this is a slow process while blood vessel radius changes any time there is a muscle contraction near the blood vessel. 2. Describe the effect of a change in blood vessel length on flow rate in the experiment. The longer a blood vessel the more surface area there is to cause resistance, by friction, to blood flow which lowers flow rate.

3. How would obesity effect the flow rate? Why? How would diabetes effect flow rate? Why? As we gain weight, or become obese, blood vessels must lengthen because our bodies have grown which means there is more friction from the vessel and this friction slows blood flow. Diabetes would decrease blood flow because it changes the elasticity of the blood vessels making them narrower which means radius is smaller and radius has a directly proportional relationship with blood flow. Act. 4 Effect of Blood Pressure on Blood Flow Rate 1. Describe the effect of pressure changes on blood flow rate from the experiment. Pressure changes are directly proportional to blood flow rate. Meaning an increase, or decrease, in pressure means an increase, or decrease, in blood flow rate. 2. Explain why pressure changes are not the best way to control blood flow. What are potential problems with pressure changes in the CV system? Pressure changes do not have as great an impact on blood flow like other factors do. For example, blood vessel radius has an exponential effect on flow rate where pressure just has a linear relationship. Overtime constant pressure changes in the cardiovascular system would wear out components such as the heart and blood vessels attached. Act. 5 Effect of Blood Vessel Radius on Pump Activity 1. Explain the effect of increasing the right flow tube radius on the flow rate, resistance and pump rate. Increasing the right flow tube radius will increase flow rate, decrease resistance, and pump rate would increase. 2. In the Experiment, what human heart volumes do the right and left beakers represent. The human heart volumes that are represented are end diastolic volume, or EDV, and end systolic volume, or ESV. Act. 6 Effect of the Stroke Volume of the Pump Activity 1. What is the Frank-Starling law in the heart? Why is it important? The Frank-Starling law states that when more blood than normal is returned to the heart, the heart will be stretched, and a more forceful contraction will occur. This means more blood will be ejected increasing stroke volume. This is important to meet the demands of the body during strenuous activities.

2. What happens to the pump rate when stroke volume is decreased? When it is increased? Pump rate will increase when stroke volume is decreased. Heart rate is increased during periods of strenuous activity causing muscles to contract. 3. How does the heart alter stroke volume? The heart alters stroke volume by changing the heart rate. Act. 7 Pathological Cardiovascular Conditions & Compensation 1. How does the heart compensate for changes in peripheral resistance? The heart increases heart rate to compensate for changes in peripheral resistance. 2. During the experiment, what happens when the pump pressure and beaker pressure are the same? There is no flow because the valve only reacts to a pressure differential. 3. According to cardiovascular system effects, would it be better to adjust heart rate or blood vessel diameter to increase blood flow to an injured extremity? It would be better to adjust blood vessel diameter to increase blood flow to an injured extremity to avoid putting unneeded stress on the heart itself....