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 development of agranulocytes, Explain Development of Agranulocytes ...

Explain Development of Agranulocytes Agranulocytes, we know, are the monocytes and lymphocytes. Agranulocytes develop in the bone marrow and thymus. They start as stem cells.

Explain intermittent positive pressure lung inflation, Explain Intermittent...

Explain Intermittent positive pressure lung inflation When medulla is affected, the cough reflex may be lost. To prevent secretions entering the lungs, a tube is inserted into

Pseudo-steady conditions, Evaporation in a mist of little drops is sometime...

Evaporation in a mist of little drops is sometimes used to cool hot, dry air. Let Consider the  Temperature in a spherical drop of liquid that is evaporating slowly enough that its

Iron age, Iron Age: We briefly surveyed the ideas and techniques of  th...

Iron Age: We briefly surveyed the ideas and techniques of  the early human beings, and traced the roots of  science in  the primitive culture. You also read about the emergence

To show how water rises by capillarity, To show how water rises by capillar...

To show how water rises by capillarity Colour some water in a shallow dish with ink and touch a blotter to the water surface. Observe how the water increases in the blotter.

Explain the menopause, Explain the Menopause The cessation of menstruat...

Explain the Menopause The cessation of menstruation is menopause. Natural menopause typically occurs between 45 and 55 years of age. It is caused by changes in concentration of

Explain dilute hydrochloric acid, Dilute hydrochloric acid   (HCl) oxidizes...

Dilute hydrochloric acid   (HCl) oxidizes only the terminal -CH20H group with the formation of uronic acid. Glucose is thus oxidized to glucuronic  acid.

Transfer from large containers, Transfer from Large Containers : As with a...

Transfer from Large Containers : As with all dangerous operations, it will pay you to think what the worst possible accident may be that could result from your actions and what wo

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