Vascular System and Vessels Flashcards
tunics of blood vessels walls (surrounding the lumen)
tunica intima- innermost lining
tunica media- middle layer, mainly smooth muscle
tunica adventitia- outermost connective tissue layer
types of arteries
large elastic arteries- near the heart, aorta
medium muscular arteries- smooth muscle fibers capable of vasoconstriction and blood flow regulation
small arteries- narrow lumina, flow into capillary beds
anastomoses
provide potential detours for blood flow if usual pathway is obstructed
neurovascular supply of a vessel
vascular smooth muscle has tone (continuous partial contraction)
modulated by visceral motor nerves- vasomotor nerves
vascular venous pumps
results of arrangement of venae comitantes
connective tissue resist expansion, arterial pulsation compresses blood flow in the veins
valves direct flow proximally
musculovenous pump
main method of venous return from limbs
expansion of contracting muscles limited by fascia
muscles contraction milks blood superiorly
thoracic venous pump
double pump mechanism linked to respiration
descent of diaphragm during inspiration shorten IVC and lengthens SVC
in expiration diaphragm ascends, SVC shortens and empties and IVC lengthens and fills
organization of lymphatic vascular system
superficial (located under epithelium) and deep (in reticular layers of dermis)
lymph capillaries drain into lymphatics
superficial nodes drain into deep nodes before emptying into venous system
lymphatic vessels
have 3 tunics
thinner walls than veins
lymph drainage facilitated by smooth muscle contractile waves
lymph nodes
act as filters to trap particulate in lymph and defend against foreign antigens
right lymphatic duct
right head and neck, right upper limb, right side of thorax, right upper abdominal
thoracic duct
from all other regions drain on left side
