Circulation (cardiovascular system) Flashcards
Pulmonary circuit?
-deoxygenated blood exits the right ventricle
-pulmonary arteries
-oxygenation at the lungs(alveoli capillary)
-oxygenation blood collects into pulmonary veins
-oxygenated blood enter the left atrium
Systemic circuit?
-oxygenated blood exits the left ventricle
-systemic arteries
-oxygen unloading at the organs
-deoxygenated blood collects into the systemic veins
-deoxygenated blood enters the right atrium
Coronary circuit?
-blood supply to the heart
Pulmonary artery carries?
deoxygenated blood
Pulmonary vein carries?
oxygenated blood
capillaries ?
connect arteries and veins
blood vessels three layers of blood vessel surrounding lumen?
1)Tunica intima
2)Tunica media
3)Tunica externa
Tunica intima
-innermost layer
-endothelium
-areolar connective tissue
-elastice membrane
Tunica media
-middle layer
-circular smooth muscle
-elastic fibers
-sympathetic stimulation of muscle
-vasoconstriction blood flow through lumen
Tunica externa
-outermost layer
-connective tissue
-blood vessels to supply tunica media and lymphatic vessels
-protective layer
Types of arteries:Elastic arteries
-closest to the heart
-wide lumen
-thick walls
-higher amount of elastin fiber
Types of arteries:Muscular arteries
-important for vascoconstriction
-thick smooth muscle layer
Types of arteries:Arterioles
-lack tunica externa
-1-2 layers of smooth muscle in media
Types of veins:Large, medium sized, venule
-have 3 tunics like arteries, expect venules only have tunica externa&very think tunica intima
-veins have broader lumen, thinner tunics
-lower blood pressure&blood velocities than arteries
what if there isn’t enough pressure gradient to return blood back to heart?
-skeletal muscle contraction pressure the vein
-valves keep unidirectional flow
Continuous capillaries?
-most common type, least permeability
-allow small solutes to pass wall
-brain, lungs, muscles
fenestrated capillaries?
-have large pores
-allow bigger solutes&small peptides to pass through
-endocrine glands, parts of intestine, kidney
Sinusoidal capillaries?
-very leaky
-allowing large molecules, proteins to pass
-liver, plasma proteins clotting factors synthesized in the liver enter blood
precapillary sphincters
-regulate access&flow through a capillary bed
-allows directing the blood flow from one capillary bed to another
Blood Flow:High pressure generated during?
-systole at the heart
Blood flow:pressure falls as?
it moves away from the heart
Blood flow:flow velocity highest in?
-aorta and the vena cava because they have the smallest total cross sectional area
Autoregulation?
intrinsic ability of an organ to maintain blood flow by regulating the blood vessels
signal triggering vasodilation?
-decrease [O2] i.e. hypoxia
-decreased pH i.e. acidosis
-increased temp
-increased lactic acid
Baroreceptors ?
-present in walls of major arteries monitor blood pressure
-activation of these tigger peripheral vasodilation, reducing blood pressure to normal
-they send signal to brain, then signal to heart to decrease cardiac output
chemoreceptors ?
-in the heart, brain, and carotid sinus monitor [O2], [CO2], pH