Samenvatting
Summary Lecture 1 Hypertentsion and the vascular system
This is a summary of lecture 1 hypertension and the vascular system. With all of my summaries for this course I passed it with an 8!
[Meer zien]Voorbeeld 2 van de 5 pagina's
Voorbeeld 2 van de 5 pagina's
In winkelwagengesponsord bericht van onze partner
Voorbeeld van de inhoud
Pathophysiology of heart and circulation – Lecture 1 –Hypertension and the vascular system
Anatomy and function
Anatomy artery
Inside to outside: endothelial cell internal elastic lamina
smooth muscle cell external elastic lamina adventitia
Vascular network
Circulation divided into 3 parts
1. Distribution/resistance: aorta large artery small artery arteriole
Aorta: pulse dampening and distribution
Large arteries: capable of constricting and dilation – but have no significant
role in the regulation of pressure and blood flow – distribution
Small arteries: distribute blood flow within the organ – distribution and
resistance
Arterioles: diameter <200 micrometer – resistance
Small arteries + arterioles primary resistance vessels. Innervated by
autonomic nerves and are richly endowed (voorzien) with receptors that bind
circulation hormones (echolamines, angiotensin II) which can alter vessel
diameter
2. Exchange: capillaries small venules
Capillaries: only endothelia cells and a basement membrane no smooth
muscle – exchange
Small venules: when capillaries join together they still have no smooth muscle
– exchange
Capillaries primary exchange vessels
3. Capacitance (most blood volume is found and regional blood volume is
regulated): large venules vein vena cava
Large venules: small venules converge now there
is smooth muscle – capable of dilating and
constricting – collection and capacitance
Vein: large venules conserve – capacitance
Vena cava: collection
Large venules + vein primary capacitance
vessels
Distribution of pressures and volumes
Pressure
Contraction of the heart pressure increases given
rise to systolic pressure (120 mm Hg)
Relaxation of the heart pressure decreases given rise to
diastolic pressure (80 mm Hg)
Pulse pressure = Psystolic – Pdistolic
, Mean aortic pressure (MAP) is 95 mm Hg and this decreases as the blood flow
further away from the heart because of energy is lost as heat
MAP = Pdiastolic + 1/3 (Psystolic – Pdiastolic)
Large arteries: blood pressure does not fall much because these vessels have low
resistance and therefore little loss of pressure energy
Small arteries and arterioles: large fall in blood pressure because these vessels have
high resistance
Capillaries: important that blood pressure is low otherwise large amounts of fluid
would leak through the capillaries causing tissue edema
Vena cava: blood pressure is close to 0
Blood pressure is affected by hydrostatic pressure
differences:
Everything below the heart: increase in hydrostatic
pressure
Everything above the heart: decrease in hydrostatic
pressure
Giraffe needs a very high blood pressure to compensate for
the highly negative hydrostatic pressure (because neck high
above the heart).
Organs that determine blood pressure:
Kidney: resorbs salts and water – affects volume of blood
Brain: nerve fibers that innervate various organs and blood vessels
Circulation hormones: affect the contractile blood vessels and inflammatory
factors
EQUATION: DeltaP = F (blood flow) * R (vascular resistance)
Blood flow is equal in the whole blood circulation
Vascular resistance refers to the resistance that must be overcome to push blood
through the circulatory system and create flow
P drops? More resistance
EQUATION: R = n (blood viscosity) * L (vessel length) / r^4 (vessel radius --
diameter)
The vascular diameter is very dynamic (dilate and contract)
Increase in vessel radius? Less resistance
Something to think about: capillaries have the smallest
diameter so why don’t they have the most resistance
instead of the small arteries and arterioles?
This is because capillaries have many parallel
pathways resistance in parallel decreases
Volume
The greatest volume of blood is found in the venous part
Voordelen van het kopen van samenvattingen bij Stuvia op een rij:
Verzekerd van kwaliteit door reviews
Stuvia-klanten hebben meer dan 700.000 samenvattingen beoordeeld. Zo weet je zeker dat je de beste documenten koopt!
Snel en makkelijk kopen
Je betaalt supersnel en eenmalig met iDeal, creditcard of Stuvia-tegoed voor de samenvatting. Zonder lidmaatschap.
Focus op de essentie
Samenvattingen worden geschreven voor en door anderen. Daarom zijn de samenvattingen altijd betrouwbaar en actueel. Zo kom je snel tot de kern!
Veelgestelde vragen
Wat krijg ik als ik dit document koop?
Je krijgt een PDF, die direct beschikbaar is na je aankoop. Het gekochte document is altijd, overal en oneindig toegankelijk via je profiel.
Tevredenheidsgarantie: hoe werkt dat?
Onze tevredenheidsgarantie zorgt ervoor dat je altijd een studiedocument vindt dat goed bij je past. Je vult een formulier in en onze klantenservice regelt de rest.
Van wie koop ik deze samenvatting?
Stuvia is een marktplaats, je koop dit document dus niet van ons, maar van verkoper biomedicalsciencesvu. Stuvia faciliteert de betaling aan de verkoper.
Zit ik meteen vast aan een abonnement?
Nee, je koopt alleen deze samenvatting voor €2,99. Je zit daarna nergens aan vast.
Is Stuvia te vertrouwen?
4,6 sterren op Google & Trustpilot (+1000 reviews)
Afgelopen 30 dagen zijn er 52510 samenvattingen verkocht
Opgericht in 2010, al 14 jaar dé plek om samenvattingen te kopen