The Cardiovascular System: Heart Critical Thinking

Front

Describe how the valves keep the blood moving in one direction.

Back

Like a one-way door. Valves open for blood flow and close to prevent backflow

Front

Why is the pressure in the pulmonary circulation lower than in the systemic circulation?

Back

Pulmonary circulations have lower pressure because it only pumps to the lungs not the whole body

Front

Why is the plateau phase so critical to cardiac muscle function?

Back

The plateau phase prevents rapid contractions, ensuring strong, steady heartbeats

Front

How does the delay of the impulse at the atrioventricular node contribute to cardiac function?

Back

It allows the atria to fully contract before the ventricles beat.

Front

How do gap junctions and intercalated disks aid contraction of the heart?

Back

They help electrical signals spread quickly, making the heart contract as one unit

Front

Why do the cardiac muscle cells demonstrate autorhythmicity?

Back

They have special pacemaker cells that create their own electrical signals

Front

Describe one cardiac cycle, beginning with both atria and ventricles relaxed.

Back

The heart relaxes, atria contract, then ventricles pump blood out. The cycle repeats.

Front

Why does increasing EDV increase contractility?

Back

More blood stretches the heart muscle making it contract stronger

Front

Why is afterload important to cardiac function?

Back

Afterload is the pressure the heart must overcome to pump blood out

Front

Why is it so important for the human heart to develop early and begin functioning within the developing embryo?

Back

The heart supplies oxygen and nutrients needed for embryo growth