thromboplastin

Thân thiện

A scientist adds thromboplastin to a blood sample in a laboratory.

Definition

1. Noun:
   • A coagulation factor: Thromboplastin is a complex enzyme (specifically, a lipoprotein) present in tissues and platelets. It is a crucial initiator in the blood coagulation cascade, acting as a cofactor for the conversion of prothrombin to thrombin.

Usage

Thromboplastin is a technical term used primarily in the fields of hematology, medicine, and physiology. It describes a specific biochemical substance essential for the process of blood clotting (coagulation).

Examples

• Noun:
  • The laboratory test measures the time it takes for blood to clot after thromboplastin and calcium are added.
  • A deficiency in thromboplastin generation can lead to abnormal bleeding.
  • The release of thromboplastin from damaged tissue is the first step in the extrinsic pathway of coagulation.

Advanced Usage

• Tissue thromboplastin: This specific term refers to thromboplastin derived from tissue sources, as opposed to platelet sources. It is a key component in common laboratory tests like the Prothrombin Time (PT).
  • The Prothrombin Time (PT) assay uses a standardized preparation of tissue thromboplastin.

Variants and Related Words

• Thromboplastic (adjective): Having the properties of or relating to thromboplastin.
  • The substance exhibited thromboplastic activity.
• Factor III: This is a synonym and alternate name for thromboplastin within the standardized nomenclature of blood coagulation factors.

Synonyms

• Factor III: The formal numerical designation in the coagulation factor series.
• Tissue factor: A common synonym, especially when referring to the form that initiates the extrinsic pathway.

Notes on Meaning

The term "thromboplastin" historically referred to a substance with both procoagulant and phospholipid activity. In modern biochemistry, its functions are often described more precisely by the terms tissue factor (the protein cofactor) and phospholipid (the surface required for the reaction). However, "thromboplastin" remains in widespread use, particularly in clinical laboratory medicine.

Học thuật

Noun

1. an enzyme liberated from blood platelets that converts prothrombin into thrombin as blood starts to clot

Từ đồng nghĩa

• thrombokinase
• factor III