Cardiac Muscle and Heart Anatomy Questions

What are the cell-to-cell contacts of the cardiac muscle fibers called?

• Z discs

• T-tubules

• Intercalated discs

• Cardiac discs

• Sarcoplasmic reticulum

The posterior interventricular sulcus

• is another name for the coronary sulcus.

• contains the great cardiac vein and coronary sinus.

• is a groove between the ventricles on the back of the heart.

• is a valve in the interventricular septum that closes at birth.

This artery is sometimes referred to as the "widowmaker" because blockage of it often leads to fatal heart attack. It serves the anterior heart and is more formally called the (2 words) ## artery.

• anterior interventricular

• circumflex

• right marginal

• posterior descending

The main functions of the cardiovascular system include the transport and exchange of respiratory gases, nutrients, and wastes throughout the body.

• true

• false

Tags

NGSS.HS-LS2-3

Vagal tone refers to the

• decreasing of the heart rate below its inherent rhythm by parasympathetic stimulation.

• decreasing of the heart rate below its inherent rhythm by sympathetic stimulation.

• increasing of the heart rate above its inherent rhythm by sympathetic stimulation.

• increasing of the heart rate above its inherent rhythm by parasympathetic stimulation.

Tags

NGSS.HS-LS1-3

The atria are separated from the ventricles externally by the

• anterior interventricular sulcus

• coronary sulcus

• posterior interventricular sulcus

• interatrial septum

Large doses of certain stimulants can lead to dangerous increases in heart rates. Such a stimulant is a

• positive chronotropic agent.

• negative chronotropic agent.

• positive inotropic agent.

• negative inotropic agent.

Cardiac reserve is

• the potential increase in stroke volume someone would show if they engaged in athletic training.

• the amount of blood remaining in the ventricles after contraction.

• the difference between systolic and diastolic blood pressure.

• the total volume of blood pumped by the heart per minute.

The right border of the heart is supplied by the

• circumflex artery.

• posterior interventricular artery.

• anterior interventricular artery.

• right marginal artery.

• great cardiac vein.

Just prior to atrial contraction,

• all four chambers are at rest and AV valves are open.

• all four chambers are at rest and AV valves are closed.

• all four chambers are contracting and all valves are open.