Human Cardiac and Respiratory Systems

A heartbeat involves a contraction phase systole and a relaxation phase diastole. These contractions of the heart are stimulated by electric...

Image found at http://www.medicalook.com/diseases_images/heart-diseases1.jpg Structure of the heart The heart is a hollow, muscular vital o...

Humans like all multicellular organisms need oxygen for cellular respiration, without this process occuring then we would die. Oxygen needs ...

• Air( carrying oxygen) is inhaled and enters the lungs • Travels through the lungs to the alveoli, oxygen is diffused out of the air, and i...

RBCs (Red blood cells) are manufactured in the red bone marrow of bones. In adults, RBCs are only manufactured in specific bones; thoracic, ...