Reference no: EM132379036
Read the summary. What three examples of form following function are evident in this description of the four-chambered heart?
Form follows function is a phrase used in many areas of study including math, architecture, ecology, and anatomy and physiology. In anatomy and physiology, form follow function is often referred more formally as the principle of complementarity where how something looks (its anatomy or form) can help us to understand how something works (its physiology or function). A good example of the principle of complementarity in anatomy and physiology is the four chambered heart. Humans, mammals, and birds can maintain a high level of activity due to the four chambered heart. In the human heart, there are two atria (right and left) that receive blood and two ventricles (left and right) that pump blood out. The right side of the heart pumps blood to the lung and is called the pulmonary circuit. The left side of the heart pumps blood to the remainder of the body and is called the systemic circuit.
The left side of the heart contains a thicker layer of muscle, compared to the right, to provide the strength of contraction to pump blood at a high enough pressure to deliver blood to the brain and to the extremities in the systemic circulation. While the left side of the heart delivers blood at a high pressure, the right side of the heart generates a much lower pressure, around 10% of the pressure generated by the left. The right side of the heart has a thin layer of muscle due to the lower pressure requirement.
Atria receive blood and contract to increases the amount of blood entering the ventricles. In a mechanism that is not yet fully understood, stretching cardiac muscle fibers changes the muscle structure to cause a stronger contraction. So, when atria increase the amount of blood entering the ventricles, this stretches the muscle and increases the strength of ventricular contraction. The increased strength of contraction allows the heart to support a higher level of activity in humans, mammals, and birds.
The right side of the heart pumps blood through the lung (the pulmonary circuit) where low pressure allows for a thinner membrane between the air in the lungs and blood in the blood vessel. A higher pressure would require a thicker membrane to avoid the pressure rupturing the membrane. Having a thin layer between air and blood in the lungs increases gas exchange with oxygen entering the blood and carbon dioxide leaving the blood. The increased ability to exchange gas allows the heart to support a higher level of activity in humans, mammals, and animals.