Polymorphonuclear Leukocytes is a term commonly used in biology and medicine to describe specific types of white blood cells that help fight off infections. The IPA phonetic transcription of this word helps to explain its spelling. /ˌpɑliˈmɔrfoʊˌnjuːkliʊts/ breaks the word down into syllables, and shows how each sound is pronounced. For example, the "polymorphonuclear" part of the word is pronounced with an emphasis on the second syllable, while the "leukocytes" part of the word is pronounced with an emphasis on the first syllable.
Polymorphonuclear leukocytes, also known as polymorphonuclear cells or PMNs, are a type of white blood cell (leukocyte) that play a crucial role in the immune system's defense against infection and disease. They are an integral part of the innate immune response.
Polymorphonuclear leukocytes are characterized by their multi-lobed nucleus, which gives them their name. This distinctive feature sets them apart from other leukocytes, such as lymphocytes and monocytes, which have a single-lobed or kidney-shaped nucleus.
These cells are primarily responsible for phagocytosis, the process by which they engulf and destroy harmful microorganisms, including bacteria, fungi, and some viruses, in a process referred to as "cellular eating." Polymorphonuclear leukocytes release potent enzymes and toxic substances to kill the pathogens they ingest.
Furthermore, these cells are known for their ability to migrate to the site of infection or tissue damage, guided by chemical signals released by injured or infected tissues. This process, called chemotaxis, allows polymorphonuclear leukocytes to quickly arrive at the site of inflammation and initiate an immune response.
The overall function of polymorphonuclear leukocytes is to eliminate invading pathogens and promote tissue healing. They are essential in the body's first line of defense against infection and are typically the first immune cells to react to an inflammatory stimulus.
The study of polymorphonuclear leukocytes is crucial for understanding immune system functions, as abnormalities in these cells can contribute to various diseases, including autoimmune disorders, chronic inflammations, and immunodeficiency disorders.
The word "polymorphonuclear leukocytes" can be broken down to understand its etymology:
1. Polymorphonuclear:
- "Poly-" is derived from the Greek word "polys", meaning "many" or "multiple".
- "Morpho-" comes from the Greek word "morphe", meaning "shape" or "form".
- "Nuclear" refers to the nucleus of a cell.
The term "polymorphonuclear" describes the multiple shapes or forms of the nucleus of these white blood cells. These cells possess a multi-lobed nucleus, which is why they are called polymorphonuclear.
2. Leukocytes:
- "Leuko-" is derived from the Greek word "leukos", meaning "white".
- "Cytes" comes from the Greek word "kutos", meaning "cell".