Leukocyte migration through capillary wall is called?
**Core Concept**
Leukocyte migration through the capillary wall is a crucial process in the inflammatory response, allowing white blood cells to reach sites of infection or injury. This process involves the coordinated action of adhesion molecules, chemokines, and other cellular components to facilitate the transmigration of leukocytes across the endothelial barrier.
**Why the Correct Answer is Right**
The correct answer, **C. Diapedesis**, is the term used to describe the process of leukocyte migration through the capillary wall. This process involves the activation of endothelial cells, which express adhesion molecules such as ICAM-1 and VCAM-1. The leukocytes, in turn, express integrins and selectins that interact with these adhesion molecules, facilitating their adhesion to the endothelial surface. The subsequent contraction of the actin cytoskeleton in the leukocytes and the endothelial cells allows for the formation of a "zipper-like" structure, enabling the leukocytes to transmigrate through the capillary wall.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe leukocyte migration through the capillary wall. While extravasation is a related term, it refers to the movement of leukocytes out of the blood vessels, but not necessarily through the capillary wall.
**Option B:** This option is incorrect because it is a term used to describe the process of leukocytes migrating through the lymphatic vessels, not through the capillary wall.
**Option D:** This option is incorrect because it is a term used to describe the process of leukocytes aggregating in the blood vessels, not migrating through the capillary wall.
**Clinical Pearl / High-Yield Fact**
The process of diapedesis is an important aspect of the inflammatory response, and its dysregulation can lead to various diseases, including atherosclerosis and cancer metastasis. Understanding the molecular mechanisms underlying diapedesis is crucial for the development of novel therapeutic strategies to modulate the inflammatory response.
**Correct Answer:** C. Diapedesis