Which term does not apply to human heart?

Options

A. Pacemaker
B. Mitral valve
C. Neurogenic
D. Four chambered

Answer

To determine which term does not apply to the human heart, we will analyze each option provided:

1. **Pacemaker**: The human heart contains a natural pacemaker known as the Sinoatrial (SA) node. This specialized group of cells is responsible for initiating the heartbeat by generating electrical impulses that spread through the heart muscle, causing it to contract. Therefore, this term applies to the human heart.

2. **Mitral Valve**: The mitral valve is an important structure in the human heart. It is located between the left atrium and the left ventricle and ensures that blood flows in the correct direction. This valve is also known as the bicuspid valve. Hence, this term also applies to the human heart.

3. **Neurogenic**: The term "neurogenic" refers to a type of heart that is controlled by nerve impulses. In contrast, the human heart is classified as a myogenic heart, where the heartbeat is initiated by specialized muscle cells rather than nerve impulses. Therefore, this term does not apply to the human heart.

4. **4-Chamber**: The human heart is a 4-chambered organ, consisting of two atria and two ventricles. This structure is essential for the separation of oxygenated and deoxygenated blood. Thus, this term applies to the human heart.

Based on the analysis of the options, the term that does not apply to the human heart is **neurogenic**.

### Final Answer: Neurogenic