Exam 3: Heart

T/F: Parasympathetic fibers innervate the SA node, AV node, and cardiac musculature.

F

T/F: The right and left coronary arteries arise from the descending aorta.

F

Which areas of the heart are innervated by parasympathetic nerve fibers?

SA and AV nodes: Parasympathetic innervation influences heart rate only because these motor fibers only innervate the sinoatrial and atriventricular nodes.

Which of these conduction sequences through the heart is correct?

SA node, AV node, AV bundle, bundle branches, Purkinje fibers

T/F : Contraction of the ventricles begins at the apex and proceeds superiorly.

T

Why is the only path of conduction for impulse transmission from the atria to the ventricles through the AV node and AV bundle?

The atria and ventricles are insulated from each other by the fibrous skeleton of the heart.

The parietal layer of the serous pericardium __________.

adheres to the inner surface of the fibrous pericardium

The fibrous skeleton of the heart functions in all of these ways EXCEPT in __________.

causing direct spread of electrical impulses from the atria to the ventricles

Which layer of the heart wall is visceral pericardium?

epicardium

Serous fluid in the pericardial cavity __________.

is secreted by the epithelial cells of both layers of the serous pericardium

The region between the right and left pleural cavities is the

mediastinum.

The cardiac centers that control heart rate are located in the

medulla oblongata of the brain stem.

Branches of the vagus nerve __________.

supply parasympathetic innervation to the heart, which slows the heart rate

The pericardial cavity lies between

the parietal pericardium and the visceral pericardium.

outer most layer of heart wall

the visceral layer of the serous pericardium (also called the epicardium).