Textbook Notes (368,877)
Canada (162,228)
Biology (363)
BIOL 153 (6)

Cardiovascular Physiology - Notes 1.doc

4 Pages
Unlock Document

BIOL 153
Paul Hewitt

NotesBlood flowElastic arteries Muscular arteriesArteriolesCapillariesVenules VeinsArteriesElastic arteriesAlso known as conducting arteriesLarge vessels up to 25 cm in diameterClose to the heartThese vessels have to cope with large pulsatile changes in pressureThe stretch in these arteries serves to dampen out the pulsatile changes in BP Specifically during ventricular diastole the elastic recoil of these arteries serve to keep BP elevatedThey have much more elastic walls than the muscular arteriesThey have a thicker tunica interna endothelium and internal elastic layerThey have a thinner tunica intermedia smooth muscle layerMuscular arteriesAlso known as distribution arteries or mediumsized arteriesThese are the arteries that carry the blood to the organs and musclesTypically they have a diameter of about 04 cmThey have a thinner tunica interna and a thicker tunica mediaArteriolesThese vessels are much smaller than the arteries30 m or lessThey have a poorly defined tunica externaThe tunica media consists of one or two thin layers of smooth muscleThe tunica media of the smallest arterioles contain scattered smooth muscle cells which dont even form a complete layerThe diameters of the smaller arterioles change in response to local conditions or to sympathetic stimulation or to endocrine signalsFor example most arterioles will dilate under low O while sympathetic 2stimulation triggers constriction Changes in diameter result in changes in the pressure required to push the blood through Smaller diametergreater pressure neededdecreased bloodflow Important noteThe number of vessels increases at each levelThus the total crosssectional area at each level increases
More Less

Related notes for BIOL 153

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.