The key difference between platelet plug and blood clot is that a platelet plug is a temporary blockage to seal an injury while a blood clot is a more permanent seal to the injury until it heals.
Platelets or thrombocytes are small and colorless fragments found in the blood. Platelets have no nucleus and are derived from bone marrow. They are found only in mammals. Platelets help in the initiation of blood clots by reacting to a damaged blood vessel or injury. Platelet plugs and blood clots aid in preventing excessive bleeding in the body. Initially, platelets attach to substances in the damaged endothelium surface through adhesion. Then platelets activate by turning on receptors, changing shape, and secreting chemical messengers. Then platelets connect and aggregate through receptor bridges. Platelet plugs are associated with activation of the coagulation cascade, and as a result, fibrin deposition takes place. This forms a blood clot. The formation of blood clots where it is not supposed to form is dangerous and life-threatening.
CONTENTS
1. Overview and Key Difference
2. What is a Platelet Plug
3. What is a Blood Clot
4. Similarities – Platelet Plug and Blood Clot
5. Platelet Plug vs Blood Clot in Tabular Form
6. Summary – Platelet Plug vs Blood Clot
What is a Platelet Plug?
A platelet plug is an aggregation of platelets that forms during the early stages of homeostasis as a result of injuries to blood vessel walls. It is also known as a homeostatic plug or platelet thrombus. When platelets start to accumulate around the damaged vessel, the adhering nature of platelets allows them to stick and attach to one another. This allows the formation of a platelet plug. Platelet plugs prevent the loss of excess blood and the entry of contaminants into the body.
Platelet plug formation is the second step in homeostasis. This process takes place after vasoconstriction. It occurs in three steps: platelet activation, platelet adhesion, and platelet aggregation. Under normal conditions, the flow of blood throughout the body takes place without noticeable aggregation of platelets since platelets are not programmed for the self-accumulation process. This results in thrombosis that is not needed. However, coagulation is necessary during homeostasis. Therefore, platelets in plasma are alerted for plug formation when the vascular endothelium triggers an automatic response in clotting and stimulates thrombin production. This is platelet activation. Once platelets are activated, they come across damaged endothelial cells. The von Willebrand factor (vWF) and fibrinogen will help platelets to adhere to the vessel walls. This is called platelet adhesion. After platelets come in contact with injured vascular cells, they start interacting with each other, and platelet aggregation takes place. When more platelets accumulate, more chemicals are released and attract more platelets. This results in platelet plugs.
What is a Blood Clot?
A blood clot is a gel-like accumulation of blood that forms in veins or arteries when the state of blood changes from liquid to solid. Blood clotting is also known as coagulation of blood. Clotting is a normal function that prevents the body from bleeding too much. They are beneficial during an injury or cut. Naturally, blood clots form as a response to an injury in a blood vessel. Once a blood vessel is damaged, platelets form a plug in the affected area. This initiates the activation of a series of clotting factors. Clotting factors are components found in plasma. Each clotting factor is a serine protease. The clotting factors are fibrinogen, prothrombin, thromboplastin, ionized calcium, proaccelerin, proconvertin, and antihemophilic factors. Vitamin K also plays an important role in blood clotting. These blood clotting factors trigger the production of fibrin, which is a strong substance that surrounds the platelet plug. Fibrin forms a mesh-like structure called fibrin clot to keep the plug strong and stable. Fibrin strengthens the blood clot and dissolves later as the injured blood vessel heals.
Blood clots are dangerous and life-threatening when they do not dissolve naturally. This condition requires medication or treatment. When a blood clot forms where it is not supposed to, it is known as a thrombus. Such clots are able to move through the body. Blood clots may form in arteries or veins. Arterial clots in the brain are known as strokes. Clots forming in the heart cause heart attacks. Blood clots also form in abdominal vessels. Such blood clots are diagnosed through blood tests, ultrasound, CT scan, MRA and MRI scans, and V/Q scans. Blood clots are treated through medication, compression stocking, surgeries, stents, and vena cava filters.
What are the Similarities Between Platelet Plug and Blood Clot?
- Platelet plugs and blood clots form due to an injury or damage to the blood vessel wall.
- They prevent bleeding following injury.
- Moreover, they occur during homeostasis.
What is the Difference Between Platelet Plug and Blood Clot?
A platelet plug is a temporary blockage to seal an injury while a blood clot is a more permanent seal to the injury until it heals. This is the key difference between platelet plug and blood clot. Platelet plugs are involved in the activity of the vWF factor, while blood clots are not involved in this factor.
The following table summarizes the difference between platelet plug and blood clot.
Summary – Platelet Plug vs Blood Clot
Both platelet plugs and blood clots help in preventing excessive bleeding. A platelet plug is a temporary blockage to seal an injury while a blood clot is a more permanent seal to the injury until it heals. Platelet plug is the aggregation of platelets that forms during the early stages of homeostasis as a result of injuries to blood vessel walls. This takes place in three major steps: platelet activation, platelet adhesion, and platelet aggregation. Blood clot or coagulation is a gel-like accumulation of blood that forms in the veins or arteries when the state of blood changes from liquid to solid. This consists of a series of enzymatic reactions which results in the conversion of fibrinogen to fibrin monomers. Fibrin strengthens the blood clot and dissolves later as the injured blood vessel heals. This summarizes the difference between platelet plug and blood clot.
Reference:
1. “Blood Clots: Risks, Symptoms, Treatments, Prevention.” Cleveland Clinic.
2.“16.5c: Platelet Plug Formation.” Medicine LibreTexts, Libretexts.
Image Courtesy:
1. “Figure 40 02 04ab” By CNX OpenStax – (CC BY 4.0) via Commons Wikimedia
2. “Blood clot diagram” By en:User:Persian Poet Gal – (CC BY-SA 3.0) via Commons Wikimedia
