The increase in size of individual cells is referred as:
**Core Concept**
Cell size increase is a hallmark of cell growth and proliferation. This process involves the synthesis of new cellular components, including proteins, organelles, and DNA, leading to an increase in cell size and eventually cell division. The growth of cells is a critical aspect of tissue repair, development, and neoplasia.
**Why the Correct Answer is Right**
The increase in cell size is primarily due to the synthesis of new cellular components, including proteins, organelles, and DNA. This process is mediated by the activation of various signaling pathways, including the PI3K/AKT pathway, which promotes cell growth and proliferation. The increase in cell size is also accompanied by an increase in the number of ribosomes, mitochondria, and other organelles, which are essential for protein synthesis and energy production.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because hypertrophy refers to an increase in cell size due to an increase in the size of the organelles and the amount of cytoplasm, whereas hyperplasia refers to an increase in cell number.
* **Option B:** This option is incorrect because atrophy refers to a decrease in cell size due to a loss of organelles and cytoplasm.
* **Option C:** This option is incorrect because metaplasia refers to a change in cell type, not an increase in cell size.
**Clinical Pearl / High-Yield Fact**
The distinction between hypertrophy and hyperplasia is critical in the diagnosis of various diseases, including cancer. Hypertrophy is a common response to injury or stress, whereas hyperplasia is often associated with neoplastic growth.
**Correct Answer: D. Hyperplasia**