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

Experiment to show where air may be found, TO SHOW WHERE AIR MAY BE FOUND ...

TO SHOW WHERE AIR MAY BE FOUND 1) Plunge a narrow-necked bottle, mouth down into ajar of water. Slowly tip the mouth of the bottle in the direction of  the surface of the water

Explain the detailed process of oil extraction, Oil extraction : Extraction...

Oil extraction : Extraction of oil from the prepared oilseeds can be done by one of the following methods: (i) traditional method: ghani, (ii) Improved methods:

First aid treatment of localized injuries, FIRST AID TREATMENT OF LOCALIZED...

FIRST AID TREATMENT OF LOCALIZED INJURIES : So far, we have seen main life-saving functions of first aid. Let us discuss the task of controlling some other injuries so that they d

Zoology, what do you mean by "super class" species "pisces"?

what do you mean by "super class" species "pisces"?

Enumerate the role of soil algae on soil flora, Enumerate the role of Soil ...

Enumerate the role of Soil algae on soil flora Soil algae are microscopic, chlorophyll containing organisms, being the simplest chlorophyllous plants. These are phototrophic ae

Define psychology, QUESTION (A) Define Psychology (B) Why is psycholo...

QUESTION (A) Define Psychology (B) Why is psychology considered a science? (C) (i) Clinical and Counselling psychology sound similar. How do they differ? (ii) Discuss a

Explain the composition of bile, Explain the Composition of Bile Bile i...

Explain the Composition of Bile Bile is a complex fluid. It is yellowish green in colour and bitter in taste. It consists of: Water Mineral salts (chloride, potassium

Explain optical specificity, Optical specificity Some enzymes exhibit a...

Optical specificity Some enzymes exhibit absolute optical specificity for at  least a portion  of the substrate molecule. For example, the enzyme maltase catalyzes the hydrolys

Making a ''burp'' bottle, Making a 'burp' bottle Fit a bottle or flask ...

Making a 'burp' bottle Fit a bottle or flask with a single-hole stopper which carries a funnel. Put the stopper firmly in the bottle and then pour water into the funnel. The bo

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