A & P Lecture #4 Study Guide- Blood Vessels – Flashcards
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Name the order of blood vessels starting and ending at the heart
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Heart>Arteries>arterioles>capillaries>venules>veins> back to heart
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What are the 3 layers of an artery/vein
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Tunica interna, Tunica media, & Tunica externa
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How many layers does a capillary have
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Only 1, Tunica interna
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What are the key characteristics of arteries
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Carry blood away from the heart, attached to ventricles,contain smooth muscle & elastic tissue
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What are the 3 types of arteries
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Elastic, Muscular, & Arterioles
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What type of artery would the aorta be classified as
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Elastic, largest and able to withstand really high blood pressure
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What is the smallest artery
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Arterioles
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What artery distributes blood to the organs
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Muscular artery
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What is an example of a muscular artery
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Renal artery
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What are the characteristics of veins
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carry blood from all tissues & return to the r & l atrium, thinner walls than arteries, contain valves in their walls, contain 65% of body's blood
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What is the smallest vein
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Venules ( collecting)
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Is the tunica media of a vein thinner or thicker than an artery, explain
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Thinner, blood pressure is lower so they do not need as much smooth muscle
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What type of vessel contains the most blood
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Veins
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What percent of blood do veins contain
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65%
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What is the function of valves in veins
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To make sure that the blood doesn't flow backwards
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Where in the body do veins CONTAIN valves
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Upper & lower limbs, neck/head
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Where in the body do veins NOT contain valves
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Thoracic & Abdominal cavities
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Name the 2 mechanisms for venous return
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Muscular Compression pump, Respiratory pump
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What happens when valves in the veins weaken
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blood tends to pool in the veins leading to varicose veins or hemorrhoids
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What does the muscular compression pump do
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contractions of skeletal muscles help push blood toward the heart, occurs during normal movement, walking
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What is the only blood vessel whose walls permit the exchange of materials
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Capillaries
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What is a continuous capillary
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Do not have pores , permit exchange of smaller substances
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What substance passes through a continuous capillary
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Water, ions
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What is a fenestrated capillary
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Contain pores
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What substance passes through a sinusoid capillary
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Proteins
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What is a siusoid
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Contain large pores, permit exchange of larger materials
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Where are the pores in continuous & fenestrated capillaries
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Tunica interna
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How does the blood flow through a capillary bed
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Bands of smooth muscle at the entrance of capillaries, precapillary sphincters alternately contract & relax, as a result blood flow occurs in pulses .
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What is vasomotion
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Cycling of contraction & relaxation of smooth muscle that changes blood flow thru capillary beds
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What is a Metarteriole
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Vessel at the beginning of capillary bed, contains precapillary sphincter
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What is a precapillary sphincter
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Band of smooth muscle that controls blood flow thru a capillary bed
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What is Thoroughfare channel
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Capillary connecting the metarteriole to the venule
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What is the direct connection of an arteriole & venule known as
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Arteriovenous anastomoses
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What does an arteriovenous anastomoses bypass
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Capillary bed
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Define blood circulation
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Related to blood pressure & the resistance in the vessels
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Define pressure
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The greater the pressure is within a blood vessel, the faster the blood flows
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What is the blood circulation formula
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Blood flow is proportional to pressure gradient divided by resistance
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What are the different types of pressures that exist within blood vessels
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Arterial, Capillary Hydrostatic pressure(CHP) & venous
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Which pressure in the blood vessels is the highest
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Arterial blood pressure,blood flows the fastest
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Which pressure is the lowest in blood vessels
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Venous, blood flows the slowest
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What blood vessel does blood flow medium
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CHP- capillary hydrostatic pressure
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Define resistance
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The LOWER the resistance, the faster the blood flows
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What are the types of resistance that exist in blood vessels
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Vascular resistance, Viscosity, & Turbulence
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What is vascular resistance
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How much friction exists between the blood & walls of the blood vessels
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What is Viscosity
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How "thick & syrupy" a fluid is
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What is Turbulence
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How "smooth" the blood flow
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If a vessel is more viscous do you have more or less resistance,
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More resistance
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What does More viscous & More resistance do to blood flow
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Slower blood flow
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If a vessel is less viscous and less resistance what happen to blood flow
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Faster blood flow
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More turbulence= more resistance= what kind of blood flow
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Slower blood flow
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Less turbulence=Less resistance= what kind of blood flow
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Faster blood flow
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Define pulmonary circuit
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Consists of vessels that carry blood FROM the heart, TO the lungs, and BACK TO the heart.
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Does the right or left ventricle pump into the pulmonary trunk
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right ventricle
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Do the pulmonary arteries contain oxygenated or deoxygeneated blood
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Deoxygenated
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During gas exchange, does oxygen move into or out of the blood
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Into the blood
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What gas moves out of the blood during gas exchange
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Carbon dioxide
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Which blood vessels return the blood from the lungs to the left atrium
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Right & Left pulmonary veins
