IX - Circulatory System Flashcards
Heart: inner layer of endothelium and subendothelial connective tissue
endocardium
Heart: middle muscular layer
myocardium
Heart: connective tissue with many adipocytes and covered by mesothelium
epicardium
Cardiac Conducting System
SA node, AV node, AV bundle of His, Purkinje fibers
Cardiac Conducting System: just beneath the endocardium of both ventricles
Purkinje fibers
Cardiac Conducting System: greater diameter, abundant glycogen, sparse bundle of myfibrils
Purkinje fibers
BV Layers: large vein
tunica externa, media, intima, endothelium
BV Layers: elastic artery
tunica externa, media, intima (internal elastic layer, endothelium)
BV Layers: medium vein
tunica externa, media, intima, endothelium
BV Layers: muscular artery
tunica externa, media, intima, endothelium
BV Layers: venule
tunica externa, endothelium
BV Layers: arteriole
smooth muscle cells (tunica media), endothelium, basal lamina
BV Layers: fenestrated capillaries
endothelial cells with pores
BV Layers: continuous capillaries
endothelial cells without pores
BV: thick walls with small lumen, rounded
arteries
BV: thin walls with large lumen, flattened
veins
Artery Layers: endothelium appears wavy due to the constriction of smooth muscle, internal elastic membrane present in larger vessels
Tunica Intima
Artery Layers: thickest layers, smooth muscle, elastic fibers, external elastic membrane present in larger vessels
Tunica Media
Artery Layers: thinner than tunica media in all but the largest arteries, collagen, elastic fibers, nervi vasorum, vasa vasorum
Tunica Adventitia
Vein Layers: endothelium appears smooth, no internal elastic membrane
Tunica Intima
Vein Layers: thinner than tunica adventitia, smooth muscle cells, collagen fibers, nervi vasorum, vasa vasorum, no external elastic membrane
Tunica Media
Vein Layers: thickest layer, collagen, smooth fibers, some smooth muscle fibers, nervi vasorum, vasa vasorum
Tunica Adventitia
Capillaries: many tight junctions, all exchange occur through cells
continuous
Capillaries: small pores
fenestrated
Capillaries: larger lumen, large spaces between endothelial cells, discontinuous basal lamina
discontinuous, sinusoids
Arteries: direction of blood flow
away from heart
Arteries: appearance
rounded
Arteries: pressure
high
Arteries: wall thickness
thick
Arteries: oxygen concentration
high - systemic, low - pulmonary
Arteries: valves
not present
Veins: direction of blood flow
towards heart
Veins: appearance
flattened
Veins: pressure
low
Veins: wall thickness
thin
Veins: oxygen concentration
low - systemic, high - pulmonary
Veins: valves
present in most, limbs, inferior to the heart
Collect excess interstitial fluid (lymph) from tissue spaces and return it to blood, distribute lymphocytes, antibodies, other immune components
Lymphatic Circulation
Lymphatic Circulation
lymphatic capillaries/lymphatics → lymphatic vessels → thoracic duct/right lymphatic duct
Lymphatics are found in most organs except
CNS, bone marrow
Lymphatic Vessels: Structure
similar to veins but with thinner walls and no distinct separation between tunics, (+) valves
Location of endothelium
Tunica Intima
Nevi vasorum control
vasoconstriction and vasodilation
Closer to the heart, arteries are expected to have a higher percentage of
elastic fibers
Leaky type of capillary in the liver
sinusoid capillary
