Blood Vessels and Circulation

Functions of CirculationCarries Blood Exchange Nutrients, waste products, and

gases. TransportationRegulates Blood PressureDirects Blood Flow

Blood VesselsTypes of Blood Vessels

Arteries Capillaries Veins

Arteries: Bring blood from the heart to other parts of the body (elastic arteries, muscular arteries, arterioles)

Capillaries: Network of very small blood vessels Veins: Bring blood from parts of the body to the heart

(Venules, small veins, medium-sized veins, large veins)

Blood Vessel StructureBlood Vessels contain 3 major layers called

TunicsTunic intimaTunic MediaTunic Adventitia

Veins, Arteries and Capillaries Structures

ArteriesElastic Arteries: Thickest walls and largest

diameter located near the heartMuscular Arteries: Contain more smooth

muscle and can regulate blood flowVasoconstriction= Contraction of smooth

muscle (decrease diameter) Vasodilation= Relaxation of blood vessels

(increase diameter)Arterioles: Thinnest walls and smallest diameter

located near capillaries

CapillariesCapillaries: Site where gas exchange occurs

between oxygenated blood and deoxygenated blood

Precapillary Sphincters: Regulates blood flow through the capillaries

VeinsVenules: Thinnest walls and

smallest diameter located near capillaries

Medium/Small Sized Veins: Larger diameter and thicker wall

Large Veins: Thickest wall and largest diameter veins with diameters greater than 2 mm contain valves, which allow blood to flow in one direction

Aging of the ArteriesAs you get older the walls of you elastic

arteries become less elastic and become stiffer. (Arteriosclerosis)

Atherosclerosis: A specific type of arteriosclerosis excess build up plaque

Systemic Pulmonary CirculationSystemic Circulation: Brings oxygenated

blood from the lungs to the heart to the rest of the body

Pulmonary Circulation: Brings Deoxygenated from the body to the heart then to the lungs