arterioles
Small blood vessels
Arterioles are the smallest arteries, branching from larger arteries to deliver blood to capillaries.
They regulate blood pressure and flow through muscular walls that can constrict or dilate: The arterioles dilate in response to heat, flushing the skin.
structure
Tiniest blood vessels
- venulesSmallest vein branches
- endotheliumCells lining blood vessels
- lumenLight output measure
- microvesselsMinute circulatory conduits
function
Arterial walls contracting inward
- vasodilationRelaxation of vessel walls
- perfusionFluid delivery to tissue
- filtrationSeparating solids from liquids
- microcirculationFlow through minute vessels
pathology
Chronic elevated arterial pressure
- atherosclerosisArterial plaque accumulation disease
- arteriosclerosisThickened, stiffened vessel walls
- ischemiaInsufficient tissue blood supply
- hypoxiaInsufficient tissue oxygenation
infarction · aneurysm · vasculitis · retinopathy · nephropathy · thrombosis
regulation
Catecholamine affecting alertness
- adrenalineEmergency response hormone
- epinephrineAdrenal stress hormone
- acetylcholineNeurotransmitter for muscles and memory
- adenosinePurine nucleoside in cells
physiology
Heart muscle contraction phase
- diastoleCardiac relaxation phase
- baroreceptorsNeurons sensing vascular pressure
capillaries
Tiniest blood vessels
- venulesSmallest vein branches
- endotheliumCells lining blood vessels
- lumenLight output measure
vasoconstriction
Arterial walls contracting inward
- vasodilationRelaxation of vessel walls
- perfusionFluid delivery to tissue
- filtrationSeparating solids from liquids
hypertension
Chronic elevated arterial pressure
- atherosclerosisArterial plaque accumulation disease
- arteriosclerosisThickened, stiffened vessel walls
- ischemiaInsufficient tissue blood supply
hypoxia · infarction · aneurysm · vasculitis · retinopathy · nephropathy · thrombosis
noradrenaline
Catecholamine affecting alertness
- adrenalineEmergency response hormone
- epinephrineAdrenal stress hormone
- acetylcholineNeurotransmitter for muscles and memory
systole
Heart muscle contraction phase
- diastoleCardiac relaxation phase
- baroreceptorsNeurons sensing vascular pressure
- Circulatory Systemheart rate, blood, veins, capillary, blood vessel
- blood vesselsvein, veins, capillaries, capillary, aorta
- circulationblood, circulation, veins, bloodstream, cardiac
- microcirculationcapillaries, venules, microvessels, microcirculation, fenestrations
- heart anatomymyocardium, endocardium, pericardium, atrium, ventricle
- brain circulationblood-brain barrier, blood brain barrier, jugular vein, sinus drainage, cerebral aneurysm