The Normal Pacemaker of the Heart Is the

question 39

Multiple Choice

The normal pacemaker of the heart is the

• A)Sinus node.
• B)AV node.
• C)Purkinje fibers.
• D)Coronary sinus.

---

Definitions:

Estuary

A coastal area where freshwater from rivers and streams mixes with saltwater from the ocean, creating a unique and biodiverse environment.

Littoral Zone

The part of a sea, lake, or river that is close to the shore, where sunlight penetrates all the way to the sediment allowing aquatic plants to grow.

Limnetic Zone

The open and well-lit area of a freestanding body of freshwater, such as a lake or pond, away from the shore.

Benthic Zone

The environmental zone found at the bottom of water bodies like oceans or lakes, encompassing the surface of the sediment and several layers beneath it.