Exam 2 – Cardio Ch 14 Flashcards
What are the major functions of the circulatory system?
Transporting nutrients to tissues
Transporting waste products away from the tissues
Transporting hormones
To maintain an appropriate environment in all tissue fluids of body for survival and optimal function of the cells
What are the components of the circulatory system?
Pulmonary circulation Superior vena cava Inferior vena cava Veins, venules, and venous sinuses Aorta Heart Arteries Arterioles and capillaries
What percentage of circulatory system is the pulmonary circulation?
9
What percentage of circulatory system is the veins, venules, and venous system?
64%
What percentage of circulatory system is the heart?
7%
What percentage of circulatory system is the arteries?
13%
What percentage of circulatory system is the arterioles and capillaries?
7%
What is the rate of blood flow through many tissues controlled by?
Mainly controlled in response to a tissue’s need for nutrients
What is the blood flow rate in a circuit?
5 L/min
What are the two main parts of the circulatory system?
Pulmonary circulation
Systemic circulation
Why are heart and blood vessels controlled?
To provide necessary cardiac output and arterial pressure to cause needed tissue blood flow
What is the function of the aorta and large arteries?
Transports blood to tissues under high pressure (100mmHg)
What type of walls do arteries have?
Strong and vascular
What type of velocity does blood flow at in the arteries?
High velocity
What is the function of arterioles?
Control site for blood flow
Major resistance site of circulation
What do arterioles control?
Conduits through which blood is released into capillaries
What type of walls do arterioles have and why?
Strong muscular walls that close arterioles completely or can, by relaxing, dilate vessels sevenfold thus having the capability of vastly altering blood flow in each tissue in response to its needs
What is the function of the capillaries?
Major site of water and solute exchange between blood and tissue
Exchange fluid, nutrients, electrolytes, hormones, and other substances between blood and interstitial fluid
What type of walls do capillaries have and why?
Thin walls and have numerous minute capillary pores permeable to water and other small molecules
What is the function of large veins and venules?
Returns blood to heart under low pressure
Serves as a reservoir of blood
What is the specific function of venules?
Collect blood from capillaries and gradually coalesce intro progressively larger veins
What is the specific function of veins?
Conduits for transport of blood from venules back to heart
Major reservoir of extra blood
Because of low pressure, venous walls are thin
muscular enough to contract or expand
Why is the musculature of veins important?
Serve as controllable reservoir for extra blood depending on needs of circulation
What is the function of the pulmonary circulation?
Site of oxygen and carbon dioxide exchange
Which component of the circulation has the largest total cross-sectional area?
Capillaries
2500cm
What does the cross-sectional area help determine?
The rate at which blood flows through it
Which component of circulation has the smallest total cross-sectional area?
2.5cm
Which component of circulation has the greatest velocity of blood flow?
Aorta
What is velocity of blood flow?
Speed at which blood flows in the circulation (mm/sec)
What is the equation for calculating velocity of blood flow?
Velocity of blood flow = blood flow/cross sectional area
Which component of circulation has the smallest velocity of blood flow?
Capillaries