Final answer:
The Coumadin ridge and Crista terminalis are structures in the heart that serve as anatomical landmarks, with the Crista terminalis also playing a role in the conduction of electrical impulses.
Step-by-step explanation:
The Coumadin ridge and Crista terminalis are structures within the heart that play roles in its anatomy and function. The Crista terminalis is a muscle ridge that separates the smooth and rough parts of the right atrium; it acts as a landmark for cardiac surgeons and is relevant in the conduction of electrical impulses within the heart. On the other hand, the Coumadin ridge is a fold of tissue within the left atrium, near the pulmonary veins, often seen during echocardiographic examinations and can be mistaken for pathological structures such as a thrombus, especially in patients with atrial fibrillation who are on anticoagulation therapy such as Coumadin.