The Mammalian Heart

Which chamber of the mammalian heart has the thickest walls?

• Left atrium

• Left ventricle

• Right atrium

• Right ventricle

Where is the tricuspid valve located?

• At the base of the aorta

• At the base of the pulmonary artery

• Between the left atrium and the left ventricle

• Between the right atrium and the right ventricle

What is the role of the semilunar valves?

• Prevent backflow of blood into the atria when the heart contracts

• Prevent backflow of blood into the atria when the heart relaxes

• Prevent backflow of blood into the ventricles when the heart contracts

• Prevent backflow of blood into the ventricles when the heart relaxes

Where is the sino-atrial node located?

• The wall of the left atrium

• The wall of the left ventricle

• The wall of the right atrium

• The wall of the right ventricle

What is the role of the chordae tendinae?

• Conduct electrical impulses across the atria

• Conduct electrical impulses down the ventricular septum

• Prevent atrioventricular valves being pushed inside out

• Prevent backflow of blood from the arteries leaving the heart

Blood is ejected from the heart during which phase of the cardiac cycle?

• Atrial diastole

• Atrial systole

• Ventricular diastole

• Ventricular systole

The first heart sound is due to what?

• Closing of the atrioventricular valves

• Closing of the semilunar valves

• Contraction of the atria

• Depolarisation of the sino-atrial node

True or false: The left atrium contracts slightly before the right atrium.

• False

• True

Which of the following are not part of the electrical conducting system of the heart?

• Atrial bundles

• Bundle of His

• Islets of Langerhans

• Purkinje fibres

What do baroreceptors respond to?

• Blood CO₂ levels

• Blood O₂ levels

• Blood pH

• Blood pressure

Tags

NGSS.HS-LS1-3