Function Of The CVS 2 Flashcards
Describe the aorta in terms of its structure and function.
The aorta is an elastic artery with a wide lumen, low resistance, and thick elastic walls that help absorb pressure changes during heart contractions.
What are muscular arteries and how do they differ from elastic arteries?
Muscular arteries have thick walls but are non-elastic, containing muscle that can contract or relax to control resistance.
Define arterioles and their role in the circulatory system.
Arterioles are small blood vessels with a narrow lumen and thick contractile walls that regulate blood flow and resistance, allowing for redirection of blood flow.
How do capillaries differ from arteries and arterioles in terms of size and structure?
Capillaries are the smallest blood vessels with a narrow lumen, approximately the diameter of a red blood cell, and have very thin walls.
Explain the significance of elastin in the walls of the aorta.
Elastin in the aorta’s walls allows for elasticity, enabling the aorta to stretch during heart contractions and return to its original size during relaxation, aiding in blood flow.
What is the function of arterioles in regulating blood flow during different activities like exercise?
Arterioles control blood flow by contracting or relaxing, thereby adjusting resistance and directing blood to specific areas such as increasing blood flow to active muscles during exercise.
Describe the structure of capillaries.
Capillaries are one layer of endothelial cells thick, providing a large surface area to volume ratio for efficient exchange of gases like oxygen and carbon dioxide.
What is the function of veins and venules in the circulatory system?
Veins and venules are capacitance vessels that store blood, with wide lumens for low resistance to blood flow and thin, distensible walls to accommodate blood storage.
Define arterioles in the circulatory system.
Arterioles are resistance vessels with narrow lumens that help control the regional redirection of blood flow.
How does the aorta function during the ejection phase of the heart cycle?
The aorta, being an elastic artery, stretches out as blood is squeezed from the left ventricle into it during the ejection phase.
Describe the role of muscular arteries in the circulatory system.
Muscular arteries have wide lumens for low resistance to blood flow, serving as conduits for blood between the aorta and arterioles.
Explain the significance of the thin wall of capillaries in gas exchange.
The thin wall of capillaries, being only one layer of cells thick, facilitates the diffusion of gases like oxygen and carbon dioxide between blood and tissues.
the function of capillaries in the circulatory system.
Caparies are tiny blood where oxygen diffuses into tissues and organs while carbon dioxide diffuses out.
Define capacitance vessels in the circulatory system.
Veins and venules are referred to as capacitance vessels due to their ability to store blood.
How are the walls of veins described in terms of flexibility and blood storage capacity?
Veins have distensible walls that can increase in diameter to store more blood.
Do the right and left sides of the heart pump blood to the same or different circulatory systems?
The right side pumps blood to the pulmonary circulation, while the left side pumps blood to the systemic circulation.
Describe the role of the interventricular septum in the heart.
The interventricular septum separates the two pumping chambers (ventricles) of the heart.
How are the atria and ventricles differentiated in terms of function in the heart?
Atria are receiving chambers where blood returns, while ventricles are pumping chambers that propel blood out of the heart.
What is the function of the aorta in the circulatory system?
The aorta carries oxygenated blood from the left ventricle to the systemic circulation.
Describe the role of the vena cava in the circulatory system.
The vena cava returns deoxygenated blood from the body to the right atrium of the heart.
How does the pulmonary trunk function in the circulatory system?
The pulmonary trunk receives deoxygenated blood from the right ventricle and bifurcates into left and right pulmonary arteries to carry blood to the lungs.
Describe the pathway of oxygenated blood in the heart starting from the left atrium.
Oxygenated blood returns to the left atrium via the pulmonary veins, fills the left ventricle, and is pumped out into the aorta to circulate the body.
What is the function of the aortic valve in the heart?
The aortic valve directs the flow of blood between the left ventricle and the aorta.
How many cusps do semi-lunar valves typically have, and why are they called semi-lunar valves?
Semi-lunar valves have three cusps and are named so because they are supposed to resemble half-moon shapes.
