Define the functions of platelets, Science

Assignment Help:

Define the functions of platelets

The main function of platelets, or thrombocytes, is to stop the loss of blood from wounds, i.e. haemostasis. Let us learn about this function. The platelets:

i) Release a chemical substance called serotonin, that cause vasoconstriction. This ensures reduced flow of blood from the injured site,

ii) Aggregate to plug the vascular plug at site of injury, and

iii) Have like skeletal muscles, actin and myosin proteins, which contract to bring about clot retraction. This ensures normal flow of blood around the sealed injured blood vessel.

The plug formed by the platelet arrests bleeding. The time taken for the blood to cease flowing from an injured site is termed as bleeding time. The platelet plug that is formed is friable and cannot be relied to check bleeding for very long. The blood forms a fibrin meshwork of threads that forms a better plug. This may take a few minutes before such a first aid mechanism acts in the body. The time taken for a clot to form is termed as clotting time. Before a patient is taken to the operation theatre, the doctor assesses the bleeding and clotting time to prevent excessive loss of blood during time of operation. The patient whose bleeding time is less than 4 minutes and clotting time is less than 12 minutes may be taken up for surgery after the other investigations are normal. So far, we have learnt about the constituents and functions of blood - the fluid connective tissue.


Related Discussions:- Define the functions of platelets

Flammable liquids , Flammable Liquids : Previously, the word flammable has...

Flammable Liquids : Previously, the word flammable has the same meaning as inflammable. Flammable liquids are those liquids or mixtures of liquids or liquids containing solids in

Fission, Fission, and fusion energy: 'The Italian navigator has arrived...

Fission, and fusion energy: 'The Italian navigator has arrived in  the new world'  This coded message announced the beginning of the atoyic age on 2nd December? 1942. The 'n

What is an index, Question 1 What is an index? Explain physician's inde...

Question 1 What is an index? Explain physician's index with the help of examples 2 How to use the Electronic Medical Record for Prior authorization and SOAP technique 3 G

How are clouds formed?, Q.How are clouds formed? During day time, on bei...

Q.How are clouds formed? During day time, on being heated, a large amount of water evaporates from various water bodies and goes into the air. A part of this water vapour also r

Media and educational environment, Media and Educational Environment: S...

Media and Educational Environment: Some  recent technological developments  in media, have opened up new horizons. Besides, increasing use of media, to support and expand educa

Chain reaction, Chain Reaction: When the atomic nucleus splits, it not ...

Chain Reaction: When the atomic nucleus splits, it not only gives off energy, but also throws out two or three more  neutrons.  'These new neutrons can,  in turn,  split two or

Carbohydrates, define carbohydrates.give a brief account on classification ...

define carbohydrates.give a brief account on classification of carbohydrates.

Explain basophils - types of white blood cells, Explain Basophils - Types o...

Explain Basophils - Types of White Blood Cells They form only 0.05% of the leukocytes. They release histamine that plays a major role in inflammatory reactions. Basophils also

Thermal veiocity, what is thermal velocity ofa material..

what is thermal velocity ofa material..

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd