Vasculature Flashcards
Describe the general anatomy of the vascular system.
- Arteries - transport blood under high pressure
- Arterioles - regulating conduits, shunt blood where it needs to be
- Capillaries - Nutrient exchange
- Venules - Collect blood from capillaries
- Veins - bring for blood back to the heart
tunica interna
- inner layer
- composed of simple squamous epithelium, plus a basement membrane
tunica media
- middle layer
- composed largely of smooth muscle tissue, site of inflammatory injury leading to plaque
tunica externa
- outer layer
- composed of connective tissue
How does velocity and pressure change as blood goes from the left ventricle to the right atria?
Velocity and pressure are high when pumping through the heart due to the force generated by LV systole, but as blood moves through the capillary beds, the velocity and pressure diminishes
What is the major function of elastic arteries?
Allow stretch as blood is pumped into them and recoil when ventricles relax, maintaining blood flow during diastole
Explain the phrase “pressure reservoir”
Pressure reservoirs maintain blood flow through the tissues during ventricular diastole
What type of vessel offers the greatest resistance to blood flow? Can this resistance be altered? Does changing this resistance offer any advantages?
- arterioles
- resistance can be altered by vasoconstriction and vasodilation by the band of smooth muscle in walls of arterioles
- yes, controls blood volume to the heart
The venous side of circulation is a low pressure side of circulation.
What does this mean in terms of blood flow?
slower blood flow than arteries but not as slow as capillaries
skeletal muscle pump
muscles surrounding the veins help pump blood
Venous valves
ensure one-directional flow of blood
Breathing
inhalation increases abdominal cavity pressure in relation to thoracic pressure creates a pressure gradient which moves blood toward heart.
Contracting atria
pulls blood into atria
