Blood Vessels Flashcards
what are the main types of vessels?
arteries, veins, capillaries and lymphatics
what are the patterns of the vessels in the body?
basic distribution pattern
what are the great vessels?
the aorta and pulmonary trunk
T/F. There can be much anatomic variance of vessels from one person to another?
T
T/F, There are many ways to clinically evaluate the vascular system (stethoscope)?
T
how does portal circulation occur?
occurs when blood travels through two capillary beds before returning to the heart
how does blood circulate through the body, what two ways?
Blood circulates through the body in two serial circulations: pulmonary and systemic.
what is the importance of the lymphatic system?
an important part of the circulatory system for returning fluid to the venous system.
what are anastomoses?
connections between vessels that can be present at birth or develop over time due to demand or disease
how do varicose veins occur?
Occur when veins loose elasticity, weaken and dilate. Valves become incompetent. Musculovenous pump may fail. This results in torturous superficial veins in the lower extremities
what is the pressure of the systemic arteries?
higher pressure, carry oxygenated blood to tissues.
what is the pressure of the pulmonary arteries?
are under low pressure, carry deoxygenated blood to lungs.
what are the characteristics of arteries?
- thicker tunica media
- no valves
- some variation
- may have anastomoses or be terminal arteries.
how can large arteries be identified?
by the presence of vasa vasorum as their thick walls require their own blood supply.
what are capillaries?
endothelial tubes that function as exchange vessels
what is the purpose of the systemic veins?
return deoxygenated blood to heart.
what type of blood do pulmonary veins carry?
carry oxygenated blood to heart.
T/F, Veins are capacitance vessels? if so, what percent of the blood is in the venous system?
Veins are capacitance vessels, most blood is in venous system (70-80%).
what are the characteristics of veins?
-thin tunica media but thicker -tunica adventitia (overall thin walled)
-larger lumen than arteries
-highly variable patterns
often multiple (venae comitantes)
-many anastomoses with other veins and with lymphatics, for thermoregulation.
T/F, veins contain valves? if so, where?
T, extremities
T/F, veins are also valveless?if so, where?
T, hepatic portal system, face
how many pumps does the venous system have? what?
The venous system has two “pumps” that enhance venous return:
the arteriovenous pump from the accompanying vein (venae comitante), an arrangement that increases venous return with arterial pulsations
and
the musculovenous pump that increase venous return with muscular contraction
what is the vasa vasroum?
supplies blood to the aorta
what is the lymphatic system?
start as blind-ended thin wall capillaries that pass through chains of lymph nodes and ultimately drain in to the thoracic duct or right lymphatic duct which return the lymph to the venous system.
what are anastomoses?
connections between vessels
why do veins and lymphatics have many?
Return of blood to the heart
T/F, Some anastomoses are present at birth?
Example: anastomoses between anterior and posterior intercostal arteries
Why is this important?
T; To supply blood to all of the thoracic wall
why do anastomoses develop over time?
Example: coronary arteries. If blockage in the anterior interventricular artery develops slowly than anastomoses can enlarge from the posterior descending and help supply the narrowed vessel
Why is this important?
due to demand or disease; to maintain blood supply
what are the different types of anastomoses?
- Arterial
- Venous
- Lymphatic
- Venous-lymphatic
- Portacaval, lack of blood flow in the liver due to cirrhosis
- Arteriovenous (shunts), due to dialysis
- Surgical anastomosis, coronary bypass by rerouting using the internal thoracic artery, Great saphenous vein used for heart bypass and sutured on aorta to the coronary vessel affected to maintain perfusion
what is the watershed area?
occurs when an area has dual supply by distal branches of two large arteries; found in the brain and marginal artery of drummond
What is the importance of this? It puts them at risk for ischemia due to lack of pressure
why do anatomic variations in the blood vessels matter? highest variability?
Understanding potential for variation and what common variations can be is important for interpreting imaging studies, surgery and the variations themselves could be clinically significant.
Variability: Lymphatics>veins>arteries
Common variations include:
Duplication of vessels
A common trunk
A split trunk
why are the pulmonary trunk and arteries thinner walled than the systemic arteries?
as they are in a lower pressure system (the pulmonary circulation).