A&P2: Circulation Flashcards
What are the micro/macroscopic vessels?
arteries and veins- macro
arterioles/capillaries/venules- micro
What are the 3 wall layers (external to internal)?
Externa (adventitia)
Media
Interna (intima)
Tunica externa (adventitia) is composed of what tissue?
Connective tissue composed of collagen fibers
Small amounts of elastic fibers present
What is the function of the tunica externa (adventitia)?
anchor vessels
What does the tunica media consist of (external to internal)?
external elastic lamina (membrane) Smooth muscle (some elastic fiber)
Tunica media containing external elastic laminas are only found in ? structure?
arteries
Where are window-like openings located that help with diffusion?
Tunica Media- elastic lamina
Tunica Interna- elastic lamina
What part of the vessel regulates the diameter of vessel lumen?
What NS innervates this?
tunica media smooth muscles
nervi vasorum innervated by sympathetic
What are the layers of the Tunica Interna (intima)
internal elastic lamina (arterial) basement membrane layer (arterial and venous) endothelial layer (arterial and venous)
What does the internal elastic lamina of the Tunica Interna consist of?
Only found in arteries
Window openings for diffusion
What part of the Tunica Interna (intima) is responsible for physical support to epithelial layer, has tensile strength (coil/recoil) and anchors endothelium to tunica media
Tunica Interna- Basement layer
What is the function of the endothelium layer of the Tunica Interna (intima)?
lining of vessel lumen
proliferates for repair (angiogenesis)
Participates in inflammatory response
Produces a lot of stuff
What does the Tunica Interna (intima) produce and what is the production used for?
Von Willebrand factor- platelet adhesion
Tissue plasminogen- promotes fibrinolysis
Thromboxane- vasoconstrictor prostaglandin
Nitric oxide- vasodilator
Prostacyclin- prostaglandin vasoDILATOR
Endothelin- vasoconstrictor
What are the two major types of arteries?
elastic
muscular
Where are elastic arteries found?
closest to heart
>10mm diameter
withstand high pressure
Elastic arteries have the highest percentage of ____ fibers
elastic
Give 6 examples of elastic arteries
aorta pulmonary trunk/arteries brachiocephalic subclavian common carotids common iliacs
What is the purpose of elastic arteries?
propel blood during ventricle diastole
Elastic arteries are aka what 2 names?
pressure reservoir- artery wall expansion allowing for momentary storage of mechanical energy
conducting arteries- conduct blood from heart to medium sized arteries
What do muscular arteries help adjust?
helps adjust rate of blood flow
muscular artery tunica media layer contains more ___fibers but less ____ fibers.
These rely on _____ to push blood forward
more smooth and less elastic (no recoil) allowing for greater vasoconstriction/dilation
musculature
Give 3 examples of muscular arteries
axillary
brachial
femoral
Muscular arteries are aka ______ arteries and utilize musculature for what 2 purposes?
distributing arteries
constrict/dilate to adjust pressure towards arterioles
Where can anastomoses develop?
between arteries, arterioles, venules or veins