Flashcards in Cardiovascular Physiology (Part 1) Deck (138)
What is the primary function of the cardiovascular system?
to deliver blood to the tissues, providing essential nutrients to the cells for metabolism and removing waste products from the cells
Do arteries or veins contain the majority of the blood volume?
The veins contain the largest percentage of blood volume
Where does the exchange of nutrients, wastes, and fluid occur?
across the capillary walls
What some other functions of the cardiovascular system?
- participates in regulation of arterial BP
- delivers regulatory hormones from the endocrine glands to their sits of action in target tissues
- participates in regulation of body temperature
- involved in the homeostatic adjustments to altered physiologic states such as hemorrhage, exercise, and changes in posture
The left heart and the systemic arteries, capillaries, and veins are collectively called the _____ circulation
The right heart and the systemic arteries, capillaries, and veins are collectively called the _____ circulation
The ___ ventricle pumps blood to all organs of the body except the lungs
The ___ ventricle pumps blood to the lungs
The two sides of the heart operate in series, what does this mean?
Blood is pumped sequentially from the left heart to the systemic circulation, to the right heart, to the pulmonary circulation, and then back to the left heart
The rate at which blood is pumped from either ventricle is called what?
Are the cardiac outputs equal between the right and left ventricles? Why or why not?
The cardiac output of the left ventricle equals the cardiac output of the right ventricle in the steady state because the 2 sides of the heart operate in series
The rate at which blood is returned to the atria from the veins is called what?
Does return to the left heart equal that to the left heart? Why or why not?
Yes, because the 2 sides of the heart operate in series
In the steady state, cardiac output from the heart _____ venous return to the heart
What are the functions of the blood vessels
- serve as closed system of passive conduits, delivering blood to and from the tissues where nutrients and wastes are exchanged.
- participate actively in the regulation of blood flow to the organ
Describe the steps involved in one complete circuit through the cardiovascular system
1) oxygenated blood fills the left ventricle
2) blood is ejected from the left ventricle
3) cardiac output is distributed among various organs
4) blood flow from the organs is collected in veins
5) venous return to the right atrium
6) mixed return to the right atrium
7) blood is ejected from the right ventricle into the pulmonary artery
8) blood flow from the lungs is returned to the heart via the pulmonary vein
Blood that has been oxygenated in the lungs returns to the left atrium via what?
the pulmonary vein
Blood that flows from the left atrium to the left ventricle goes through what valve?
the mitral valve
Blood leaves the left ventricle through what valve?
the aortic (semilunar) valve
What percentage of cardiac output is delivered to the brain?
What percentage of cardiac output is delivered to the heart?
What percentage of cardiac output is delivered to the kidneys?
What percentage of cardiac output is delivered to the GI tract?
What percentage of cardiac output is delivered to skeletal muscle?
What percentage of cardiac output is delivered to the skin?
What are the 3 major mechanisms for achieving a change in blood flow to an organ system?
- CO remains constant, but the blood flow is redistributed among the organ systems by selective alteration of arteriolar resistance
- CO increases or decreases, but the percentage distribution of blood flow among the organ systems is kept constant
- both CO and the percentage of blood flow are altered
When are both CO and the percentage of blood flow are altered?
In response to strenuous exercise: blood flow to skeletal muscle increases to meet the increase metabolic demand by a combination of increased CO and increased percentage distribution to skeletal muscle
What is the largest vein?
the vena cava
Is pressure higher in the vena cava or in the right atrium? Explain the importance of this
Pressure is higher in the vena cava which allows for blood to flow into the right atrium