The fibrous skeleton of the heart functions in all of these ways except in the fibrous skeleton of the heart functions in all of these ways except in acting as the point of insertion for bundles of cardiac muscle in the atria and ventricles anchoring the valve cusps causing direct spread of electrical impulses from the atria to the ventricles lining the heart chambers, covering the heart valves, and forming the ridge of the crista terminalis preventing overdilation of the valve openings

The fibrous skeleton of the heart functions in all of the ways listed in the option, except causing direct spread of electrical impulses from the atria to the ventricles. The fibrous skeleton in fact supports proper coordination of atrial and ventricular contractions by blocking direct spread of electrical impulses from atria to ventricles.

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.

and after water is usually warmed by the sun the water temperature raises and then evaporates .