Question

Which of the following term does not apply to human heart? (a) Pacemaker (b) Four chambered (c) Mitral valve (d) Neurogenic

Short answer

The term that does not apply to a human heart is (d) Neurogenic.

Step-by-step solution

Understand the Terms

First, understand what each term means. The pacemaker is a group of cells that regulate the heartbeat. The human heart is described as four-chambered because it consists of two atria and two ventricles. The mitral valve, also known as the bicuspid valve, is one of the four valves in the human heart, and it allows blood to flow from the left atrium to the left ventricle. Neurogenic refers to the origin or cause in the nervous system or in nerves.

Correlate Terms with Human Heart

Correlate each term with the human heart. The pacemaker, four-chambered description, and mitral valve all directly relate to the heart's structure and function.

Identify the non-applicable term

The term, 'Neurogenic', doesn't directly apply to the human heart. While the heart is connected to the nervous system, the term 'Neurogenic' itself refers to something originating in the nerves and is typically used to reference conditions or issues that stem from problems in the nervous system, not the functioning or structure of the heart.

Key concepts

Pacemaker in Heart

The pacemaker in the heart, also known as the sinoatrial (SA) node, is a small cluster of cells located in the right atrium. It's the heart's natural rhythm controller, generating electrical impulses that set the rate and timing of heartbeats.
This 'natural pacemaker' prompts the heart to contract, pumping blood throughout the body. A remarkably minute structure, its power in orchestrating the beat of the entire heart is immense. The electrical signals it produces are swift and travel through pathways in the heart, ensuring both atria contract simultaneously, followed by the ventricles.
In medical situations where an individual's heart rhythm is irregular or slow, an artificial pacemaker may be employed. This small device is implanted near the heart to help manage the heartbeat but only steps in when the natural pacemaker fails to maintain an adequate rhythm.

Four-Chambered Heart

The human heart is an organ of marvel, exemplified by its elaborate four-chambered structure. This configuration, consisting of two atria on the top and two ventricles at the bottom, ensures highly efficient blood circulation within our bodies. Each chamber has its unique role in the heart's cycle.

• The right atrium receives oxygen-poor blood from the body and sends it to the right ventricle.
• The right ventricle pumps the blood to the lungs for oxygenation.
• The left atrium welcomes oxygen-rich blood from the lungs.
• The left ventricle, the most powerful, then propels this blood to the entire body.

This dual-pump system separates oxygen-rich from oxygen-poor blood, enabling humans to have a highly efficient and energetic metabolism, supporting complex activities and the demands of an active brain.

Mitral Valve Anatomy

Diving into the depths of the heart, one discovers the mitral valve, distinguished by its two flaps, or leaflets. Nestled between the left atrium and left ventricle, this valve plays a pivotal role in unidirectional blood flow.
When the heart rests in between beats, the mitral valve opens, permitting blood to flow from the left atrium to the left ventricle. As the ventricle contracts, the leaflets shut tightly, blocking any backflow of blood into the atrium. This mechanism ensures efficiency and contributes to the heart's diligent work in sustaining life.
Patients with conditions like mitral valve prolapse or stenosis might experience issues with the valve's function, prompting the need for medical intervention. Understanding its anatomy allows for an appreciation of the precise orchestration required for a heartbeat.