The Human Heart and Circulatory System Quiz

Fish Heart Structure

• The heart of a fish typically has two chambers: an atrium and a ventricle, which is a simpler structure compared to other vertebrates.

Heart Protection

• The protective sac enclosing the heart is called the pericardium, which serves to reduce friction and protect the heart as it beats.

Heart Rhythm Regulation

• The rhythm of the heart's blood-pumping action is primarily determined by the sinoatrial (SA) node, also known as the natural pacemaker, which generates electrical impulses that trigger heartbeats.

Human Heart Location

• The human heart is located within the thoracic cavity, specifically in the mediastinum, between the lungs and just above the diaphragm.

Asymmetric Heart Orientation

• An asymmetric orientation of the heart in all vertebrates is caused by embryological development and the positioning of thoracic organs, which leads to a consistent leftward tilt or rotation of the heart.