Open Question
Define each term:
a. Pressure gradient
b. Blood pressure
c. Blood flow
d. Resistance
19. The Blood Vessels
Introduction to Hemodynamics
Back19. The Blood Vessels
Introduction to Hemodynamics
- Multiple Choice
Arteries tend to have thicker walls than veins. Which of the following is a reason for this?
- Multiple Choice
The pressure at point A in the circulatory system is 15 mm Hg, & the pressure at point B is 8 mm Hg. Blood is flowing from point A to point B, then a physiological change causes the pressure at point B to increase to 10 mm Hg. What will happen to the rate of blood flow?
- Multiple Choice
Which of the following physiological changes would likely occur in someone’s blood vessels when they begin an intense exercise session?
- Multiple Choice
Assuming each of these blood vessels have the same difference in pressure along their length, which would have the lowest resistance and therefore, the greatest rate of blood flow?
- Multiple Choice
Blood vessels primarily impact resistance to blood flow by:
- Open QuestionVern is suffering from cardiac arrhythmias and is brought into the emergency room of a hospital. In the emergency room he begins to exhibit tachycardia and as a result loses consciousness. Explain why Vern lost consciousness.
- Open QuestionWhen we are cold or the external temperature is low, most venous blood returning from the distal part of the arm travels in the deep veins where it picks up heat (by countercurrent exchange) from the nearby brachial artery en route. However, when we are hot, and especially during exercise, venous return from the distal arm travels in the superficial veins and those veins tend to bulge superficially in a person who is working out. Explain why venous return takes a different route in the second situation.
- Open QuestionWhich of the following would not result in the dilation of the terminal arterioles and upstream arterioles in systemic capillary beds?a. a decrease in local tissue O₂ content,b. an increase in local tissue CO₂,c. a local increase in histamine,d. a local increase in pH.
- Open Question
Mark the following statements as true or false. If a statement is false, correct it to make a true statement.
e. The sympathetic nervous system causes vasodilation in the skin when body temperature decreases.
- Open QuestionWhy is blood flow to the brain relatively continuous and constant?
- Open QuestionCompare the effects of the cardioacceleratory and cardioinhibitory centers on cardiac output and blood pressure.
- Open QuestionBob is sitting outside on a warm day and is sweating profusely. Mary wants to practice taking blood pressures, and he agrees to play the patient. Mary finds that Bob's blood pressure is elevated, even though he is resting and has lost fluid from sweating. (She reasons that fluid loss should lower blood volume and, thus, blood pressure.) Why is Bob's blood pressure high instead of low?
- Open QuestionBlood is transported through the venous system by means of (a) skeletal muscle contractions, (b) decreasing blood pressure, (c) the respiratory pump, (d) a and c.
- Open QuestionThe most important factor in vascular resistance is (a) the viscosity of the blood, (b) the diameter of the lumen of blood vessels, (c) turbulence due to irregular surfaces of blood vessels, (d) the length of the blood vessels.