Chapter 19 - Blood Vessels Flashcards
What is the intrinsic conduction system?
The hearts ability to beat, ensures heart muscle depolarizes in an orderly and sequential fashion, from atria to ventricles, and the heart beats as one unit
Intrinsic Conduction System Path
SA Node, AV Node, AV Bundle, R + L Bundle Branches, Perkinje Fibers
Role of SA Node + Depolarization rate
Pacemaker of the heart, depolarizes 75/minute
Role of Purkinje Fibers
Ensure heart is completely depolarized
What is the length of a cardiac cycle?
Start of P wave to next P wave
What is the P Wave?
Atrial depolarization
What is the QRS Complex?
Ventrical depolarization
What is the T wave?
Ventrical repolarization
What does an elevated ST Segment suggest?
Heart attack or just had a heart attack
What does an elevated ST Segment suggest?
Heart attack or just had a heart attack
What happens after depolarization?
Blood is being pumped out of the heart via ventricles
What is repolarization?
Ventricles are relaxing
What is the role of the tunica media? What is it composed of?
Regulate blood pressure by controlling diameter of vessel; larger and thicker in arteries; Composed of smooth muscle and elastin
What is the role of the tunica externa? What is it composed of?
Support + Protection; composed of areolar and fibrous tissue
What do veins have that arteries do not?
Valves due to little blood pressure, allowing blood to move up
What is the role of a capillary/
Meet tissue needs via diffusion
What is the role of an artery?
Carry blood away from the heart
What is the role of a capillary?
Provide for exchange of materials between blood and tissue cells; care for tissue needs
What is the size of the tunica intima in a vein?
Larger in veins due to bigger lumen
What is the role of a venule?
Connect capillary to vein
What is the role of an arteriole?
Regulates pressure in capillary, connects artery to capillary
What is the role of the tunica intima? What is it composed of?
Lines lumen of a vessel, composed of endothelium, subendothelial layer and internal elastic membrane
What is the role of the smooth muscle in the tunica media?
Controls the diameter of vessels to regulate blood flow and pressure
In larger vessels, what does the tunica externa contain?
Contains system of tiny blood vessels called vasa vasorum
How does the size of arteries compare to that of veins?
Walls of arteries are thicker than veins
What is an elastic blood vessel? Function? Found Where?
Largest and contain more elastic tissue than other arteries; function is pressure reservoir for continuous blood flow; found in the aorta, brachiocephalic artery, common carotid artery
What is a muscular artery?
Distributing arteries, most numerous, less elastic
What is a muscular artery?
Also called a distributing artery, most numerous, has more smooth muscle, less elastic tissue
What is the function of a muscular artery? Where found?
Constriction (But less stretch) and distributes blood to specific areas of the body; examples: brachial and radial artery
Describe arterioles
Smallest type of artery, very thin tunica externa
What is the function of an arteriole?
Function: move blood from arterioles to capillary beds, regulate blood flow to specific areas
Describe capillaries
Only contain tunica intima
What is a venule?
Smallest type of vein
What is a venule’s function?
Drain capillary beds and merge to form veins