Based on the size and function, arteries can be divided into these three categories.
elastic (conducting) arteries
muscular (distributing) arteries
arterioles
These are thick-walled arteries near the heart (aorta and major branches). Large lumens make them low-resistance pathways that conduct blood from the heart to medium-sized arteries.
elastic (conducting) arteries
These arteries deliver blood to specific body organs, have the thickest media of all vessels, and are more active in vasoconstriction and less distensible.
Muscular (distributing) arteries
These are the smallest of the arteries, lead into the capillary beds, single layer of smooth muscle cells spiraling around endothelial lining.
Arterioles
Capillaries are the smalles blood vessels and can be categorized structurally as what 3 types?
continuous
fenestrated
sinusoidal
The flow of blood from an arteriole to a venule through a capillary bed is called this.
microcirculation
Capillary beds are interweaving networks that consist of these two types of vessels.
vascular shunt
true capillaries
A short vessel that directly connects the arteriole and venule at opposite ends of the bed
vascular shunt (metarteriole)
These carry blood from the capillary beds to the heart.
veins
These are formed when capillaries unite.
venules
These are formed when venules join to form thin walled larger structures.
veins
The venous system consists of thick longitudinal bundles of these fibers and elastic networks.
Collagen
Percentage of body's blood supply in the veins at any time.
65%
How much the elastic arteries close to the heart can be stretched and the volume of blood forced into them at any time affects this.
Arterial blood pressure
This is the difference between the Ps and Pd.
Pulse pressure
The pressure that propels blood to the tissue.
MAP
Three reasons low capillary pressures are desirable.
capillaries are fragile, easily ruptured
extremely permeable - low pressures filtrate fluids into interstitial space
fluid flows are important for refreshing interstitial fluid