Read the following statements about the internal structure of the human heart: I. Humans have an auto-excitable, chambered, muscular and myogenic heart. II. The heart is mesodermal in origin and is present symmetrically between two lungs in the thoracic cavity. III. The opening between the right atrium and left ventricle is guarded by a tricuspid valve. IV. Only the sino-atrial node of the heart has the ability to generate action potentials without any external stimuli. How many statement/s is/are incorrect from the above?

Question

Read the following statements about the internal structure of the human heart: I. Humans have an auto-excitable, chambered, muscular and myogenic heart. II. The heart is mesodermal in origin and is present symmetrically between two lungs in the thoracic cavity. III. The opening between the right atrium and left ventricle is guarded by a tricuspid valve. IV. Only the sino-atrial node of the heart has the ability to generate action potentials without any external stimuli. How many statement/s is/are incorrect from the above? (A) Two (B) Three (C) Four (D) One

Tardigrade Admin · Accepted Answer

Heart is mesodermal in origin and is present asymmetrically between two lungs in the thoracic cavity.
The opening between the right atrium and right ventricle is guarded by a tricuspid valve, whereas between left atrium and left ventricle is guarded by a bicuspid or mitral valve.
The entire nodal structure of the heart has the ability to generate action potentials without any external stimuli. This includes the SAN, AVN, AV bundle, etc.