Extravasation

Definition

Extravasation is the process by which white blood cells exit the bloodstream through the endothelial lining of blood vessels to reach sites of infection or injury. This process is crucial for initiating an effective immune response.

5 Must Know Facts For Your Next Test

1. Extravasation involves a multi-step process including rolling, adhesion, and transmigration.
2. Selectins and integrins are key molecules mediating the adhesion and migration of white blood cells during extravasation.
3. Chemokines released at infection sites guide white blood cells to specific locations during extravasation.
4. Defective extravasation can lead to impaired immune responses and increased susceptibility to infections.
5. Phagocytic cells like neutrophils and macrophages utilize extravasation to reach and eliminate pathogens.

Review Questions

• What are the main steps involved in the process of extravasation?
• Which molecules play a critical role in mediating white blood cell adhesion during extravasation?
• How do chemokines influence the process of extravasation?

Related terms

Phagocytosis:

The process by which certain living cells called phagocytes ingest or engulf other cells or particles.

Chemotaxis:

The movement of an organism or cell toward or away from a chemical stimulus.

Endothelial Cells: Cells that line the interior surface of blood vessels and lymphatic vessels.