Hemostasis is a process to stop bleeding that requires coordinated activities of vascular, platelet, and plasma factors. Under normal conditions, blood vessel injury will trigger endothelial cells to secrete factors that promote adhesion and activation of platelets. First, platelets bind to von Willebrand’s factor (vWF) secreted by endothelial cells through vWF receptors. Attached platelets then undergo degranulation and release factors such as serotonin, which causes vascular constriction. Activated platelets also release other mediators to attract additional platelets for aggregation at the injured sites.
Biomedical Laboratory Science
Showing posts with label Platelets. Show all posts
Showing posts with label Platelets. Show all posts
Monday, September 26, 2016
Friday, September 23, 2016
What Do We Really Need To Know About Platelets And The Laboratory?
What is a platelet? The anatomic definition of a platelet is well established: According to MedicineNet.com, it is “an irregular, disc-shaped element in the blood that assists in blood clotting. During normal blood clotting, the platelets clump together (aggregate). Although platelets are often classed as blood cells, they are actually fragments of large bone marrow cells called megakaryocytes.” This definition, however, does not do justice to our rapidly expanding understanding of the platelet’s roles, functions, and laboratory applications.
What the numbers say
Laboratories with the ability to detect platelet function defects still tend to focus on identifying the two percent of the population that have heritable platelet function defects and von Willebrand Disease.
Source: MedicalLaboratoryObserver
Thursday, April 28, 2016
Complete Blood Count in Primary Care
Key points
To provide an overview of the use of the complete blood count in primary care and to provide advice on appropriate follow-up for abnormal results.
Introduction
The complete blood count (CBC) is the most frequently requested blood test in New Zealand. The primary points of interest in the CBC are often whether a patient is anaemic, whether the white count shows evidence of infection and whether the platelets are at a level that may affect haemostasis.
GPs have told us they are reasonably comfortable interpreting CBC results with marked abnormalities, but would like guidance when the results show only subtle abnormalities or when the clinical picture is not clear.
This is a consensus document
This is not a comprehensive document covering all causes of abnormal results; it is a consensus document produced in conjunction with specialist haematologists, providing an overview for some scenarios encountered in primary care.
Background
Haematopoiesis - Cell development
All blood cells are produced within the bone marrow from a small population of stem cells. Less than one in 5000 of the marrow cells is a stem cell. These cells represent a self-renewing population.
Download here: Complete Blood Count in Primary Care
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