17.2 Chapter Human Structure and Function

2 Types of heart valves

atrioventricular valves(AV), Semiulnar valves

atrioventricular valves(AV)

prevents backflow of blood into atria during ventricular contraction

Semiulnar valves

guard the bases of large arteries coming from the ventricles, prevents 

backflow into ventricles

Right AV name

Tricuspid

Left AV name

Mital Valve

Chordae tendineae

small collagen cords attached to each AV flap, Anchor cusps to papillary muscles protruding from ventricular walls

When is AV open

When heart relaxed AV is open, AV flaps hang limply into ventricular chambers, blood flows into atria and through AV into ventricles

When is AV closed

When ventricles contract blood is compressed into their chambers, Intraventricular pressure rises forcing blood against valve flaps flap edges meet closing the valve

Left semiulnar valve name

Aortic valve

Right semiulnar valve name

pulmonary valve

When are semiulnar valves open

Pressure high, contraction

When are semiulnar valves closed

Heart relaxed

Location of semiulnar valves

Bases of large arteries

AV valve location

Atrial-ventricular junction