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A&P 2:Ch. 19 Vessels
Term | Definition |
---|---|
Tunica Intima/Interna (Arteries) | Endothelial lining of simple squamous; Underlying CT; Includes a layer of elastic fibers |
Tunica Intima/Interna (Veins) | Endothelial lining of simple squamous; Underlying CT |
Tunica Media | Concentric Layer of smooth muscle & CT; Thicker in Arteries |
Vasoconstriction (in Tunica Media) | Contraction of smooth muscle to decrease diameter in vessel |
Vasodilation (in Tunica Media) | Relaxation of smooth muscle from reduced stimulation; increase in vessel diameter |
Tunica Externa/Adventitia (Arteries) | Sheath of collagen & elastic fibers that connect surrounding tissue for stabilization. |
Tunica Externa/Adventitia (Veins) | Sheath of collagen & elastic fibers that connect surrounding tissue for stabilization; Include additional smooth muscle cells; Thicker than in Arteries |
Arteries | Carry blood away from heart; able to stretch and recoil with pressure change |
Arteries | Usually round with a relatively thick wall |
Veins | Usually larger & have flattened/collapsed walls |
Arterioles | poorly defined Tunica Externa & only has 1-2 layers of smooth muscle in Tunica Media. |
Arterioles & Arteries | Carry blood away from heart to capillary beds where gas & nutrients/waste is exchanged. |
Veins & Venules | Carry blood from capillary beds to heart; have valves to prevent backflow of blood to capillary beds |
Varicose Veins | Superficial veins become distended & the valve no longer prevents backflow of blood |
Venous System | Muscle contractions squeezes blood in veins toward heart |
Capillaries | Consists of a tube of endothelial cells within a basal lamina |
Fenestrated Capillaries | Allow rapid exchange of water & solutes between plasma & interstitial fluids |
Sinusoids (Capillaries) | Have gaps between adjacent cells that allow free exchange of water & solutes up to the size of plasma proteins; occur in Liver, Bone Marrow, Spleen & other Endocrine Glands |
Capillary Beds | Path of blood flow can be regulated |
Vasomotion (In Capillary Beds) | Vasoconstriction occurring rhythmically so blood "pulses" through capillary beds |
Anatsomoses (In Capillary Beds) | Reconnection of 2 streams previously branched out; provides alternative pathways for blood flow |
Pulmonary Circuit | Heart to Lungs and back |
Pulmonary Arteries | Carry Deoxygenated blood |
Systemic Circuit | Heart to Tissues and back |
Aorta | Large, elastic artery extending from left ventricle; All systemic arteries originate here |
Superior & Inferior Venae Cavae | All Systemic Circulation merge into 2 large veins: (name them) |
Superior & Inferior Venae Cavae | Return Deoxygenated blood to the right side of the heart |
Superficial and Deep Peripheral Veins | 2 Sets of Peripheral Veins: (name them) |
Superficial and Deep Peripheral Veins | One of each in the venous system; pathways are important for body temperature regulation. |