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

Explain the stagnant or ischemic hypoxia, Explain the Stagnant or Ischemic ...

Explain the Stagnant or Ischemic Hypoxia It is a hypoxia resulting from slow peripheral circulation (such as follows congestive cardiac failure). In this, the blood flow to the

Fossil, Describe the typical conditions neccessary for fossil formation

Describe the typical conditions neccessary for fossil formation

Environmental science, The debris resulting from mountaintop removal mining...

The debris resulting from mountaintop removal mining is Answer A. dumped into valleys and streams below B. ground and combined with cement to make concrete C. resold as soil

Food chain, what happens if one animal is not there

what happens if one animal is not there

Name the primary minerals present in an igneous rock, a)  Name the primary...

a)  Name the primary minerals present in an  igneous rock.  a )  Quartz (SiO2), feldspars, amphiboles, pyroxenes and micas are the most common primary minerals in igneous  rock

Which of the following would NOT affect gass exchange?, A) thickness of the...

A) thickness of the respiratory membrane B) gas concentration gradients C) decrease in pulmonary ventilation D) lung surface area E) no exceptions

Code of practice in a laboratory, Code of Practice in a Laboratory The ...

Code of Practice in a Laboratory The following is a set of rules you should follow while working in a laboratory: 1. Always wear the required protective clothing. 2. Make

Maintaining laboratory safety, OBLIGATIONS OF THE TEACHERS AND THE HEAD OF ...

OBLIGATIONS OF THE TEACHERS AND THE HEAD OF THE INSTITUTION TOWARDS MAINTAINING LABORATORY SAFETY Safety in laboratory work is the collective responsibility of the Head of the

Air pollution by carbon monoxide, Air pollution by Carbon monoxide: Ca...

Air pollution by Carbon monoxide: Carbon monoxide is produced when organic materials such as gasoline, coal, charcoal, and trash are incompletely burnt. Virtually all stoves,

Inferential Satatics, Histograms and Descriptive Statistics Resources Websi...

Histograms and Descriptive Statistics Resources Website icon Histograms and Descriptive Statistics Scoring Guide. MS Word Icon Step-by-Step Guide: Histograms and Descriptive Statis

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