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

Transport in river valley civilisations, Transport: River Valley civi...

Transport: River Valley civilisations were characterised by  settlements along the rivers and growth of cities which needed, among.other  things, stones and wood from distant

Define the functions of cerebrospinal fluid, Define the Functions of Cerebr...

Define the Functions of Cerebrospinal Fluid The CSF has many functions. These include the following: 1) It provides the optimum condition for a meaningful signal/stimulus. T

State the pipette method of soil, State the Pipette Method of soil The ...

State the Pipette Method of soil The   sieve analysis, though is a true particle size analysis, is  unable to separate particles smaller than 20 microns. Such particles are sep

Lesson 1, Does a piece of glass reflect more light than a piece of paper?

Does a piece of glass reflect more light than a piece of paper?

Differences between tumor staging and tumor grading, Describe the differenc...

Describe the differences between tumor staging and tumor grading, and how each is performed. Relate the role of your particular imaging modality in staging and or grading, if any

Determine the amount of amino acids in urine, Determine the amount of Amino...

Determine the amount of Amino acids in Urine Normal urine contains only small amount of certain amino acids, for example, glycine and glutamine. Abnormal amounts and types of a

Define the term pulses, Pulses Pulses are the edible fruit or seed of ...

Pulses Pulses are the edible fruit or seed of pod-bearing plants and are widely grown throughout the world. They have a high protein content ranging from 20-40%, which makes th

Explain the malformations or birth defects of genital organs, Explain the M...

Explain the Malformations or Birth Defects of Genital Organs Other gynaecological morbidities cover congenital malformations or birth defects of the genital organs. These occur

Chemical evolution of spontaneous generation, Chemical Evolution The qu...

Chemical Evolution The question of  how life came into being in  the first place still remained unanswered. To  find an answer to this question means looking back billions of y

Digestive system, size and length of val vulae connenvitis

size and length of val vulae connenvitis

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