Blood Vessels and Circulation Flashcards
Five blood vessels
arteries, arterioles, capillaries, venules, and veins.
Arteries Function? Walls consist?
blood away from the heart to body tissues
endothelium, smooth tissue (middle layer), and outer layer.
Middle layer of arteries structure?_____ & _____
Constriction and elastic
What are arterioles? Function?
are small arteries that deliver blood to capillaries.
Through constriction and dilation, arterioles play a key role in regulate blood flow from arteries into capillaries
Vasoconstriction: decreases or increases blood vessel lumen?
decrease in the diameter of the blood vessel lumen
Vasodilation? Increase or Decrease?
is an increase
Are microscopic blood vessels that connect arterioles to venoules
Capillaries
Capillaries Function?
Exchange vessels; through permitting exchange of nutrients and wastes b/w the body’s cells and the blood.
Regulate blood flow through capillaries
Precapillary Sphincters
“Pushes” fluid out of capilaries INTO ISF= Filteration
Capillary blood pressure
What “pulls” fluid into capillaries from ISF?
Blood osmotic pressure through ISF = Reabsorption
Ability of a tissue to automatically adjust its blood flow to match its metabolic demands.
Autoregulation
Capillary exchange
Photo (slide 10)
Small veins, similar in structure to arterioles; their walls are thinner near capillary end and thick as they progress towards heart
Venules
Structurally similar to arteries, but their middle and inner layers are thinner
Veins
Thickest layer of Veins
Outer. The lumen of a vein is larger than an artery’s lumen.
Which layer of the veins folds inwards to form ?
In some veins, the inner layer folds inward to form valves that prevent the backflow of blood.
Varicose veins are?
Weak, bulging venous valves
Movement of blood from capillaries to venules to veins back to the HEART. Aided by what?
Venous return. This is aided by the skeletal muscle pump, and breathing (the respiratory pump).
Skeletal Muscle Pump
Slide 13.
________: From regions of higher pressure to regions of lower pressure; the greater the pressure difference, the greater the blood flow.
Blood flows
Generates blood pressure (BP), This pressure is recorded in mm Hg,= Mercury
Contraction of the ventricles
_______ ______: depends in part on the total volume of blood in the cardiovascular system (about 5 liters). Cardiac output
Blood pressure