The myocardium is best described as:

• The inner lining of the heart

• The outermost sac of the pericardium

• The thick muscular layer of the heart wall

• The valve separating the ventricles

What supplies oxygen-rich blood to the heart muscle?

• Cardiac arteries

• Coronary arteries

• Coronary capillaries

• Pulmonary veins

Which valve controls blood flow from the right atrium to the right ventricle?

• Aortic valve

• Pulmonary valve

• Tricuspid valve

• Mitral valve

Blood returning from the lungs enters which chamber?

• Right atrium

• Left atrium

• Left ventricle

• Right ventricle

Which type of blood vessel allows for exchange of gases and nutrients?

• Arteries

• Veins

• Arterioles

• Capillaries

Tags

NGSS.HS-LS2-3

Which electrical structure causes the ventricles to contract?

• SA node

• AV node

• Purkinje fibers

• Mitral valve

Which layer of arteries allows them to vasoconstrict and vasodilate?

• Tunica externa

• Tunica media

• Tunica intima

• Myocardium

Which blood vessels contain valves to prevent backflow?

• Arteries

• Capillaries

• Veins

• Arterioles

Which side of the heart contains oxygen-rich blood?

• Right atrium and right ventricle

• Right ventricle and left atrium

• Left atrium and left ventricle

• Right atrium and left ventricle

Which chamber pumps blood into systemic circulation?

• Right atrium

• Right ventricle

• Left atrium

• Left ventricle