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

Air borne diseases, Air Borne Diseases: A number of diseases are caused...

Air Borne Diseases: A number of diseases are caused due to bacteria and virus that are carried in the air. When an infected person sneezes  or coughs, there is a noticeable spr

Where the water table intersects the surface, What is the term for groundwa...

What is the term for groundwater emerging naturally at the ground surface, where the water table intersects the surface: Spring is the term for groundwater emerging aturally

Dew-point temperature, Dew-point temperature You can calculate the dew-...

Dew-point temperature You can calculate the dew-point temperature with a shiny can having some water, a thermometer and some ice. The dew-point temperature is an significant we

Life science, b) discuss briefly the scientific and technical achievements ...

b) discuss briefly the scientific and technical achievements of the bronze age

Types of diseases, Types of Diseases As we  have indicated above. the...

Types of Diseases As we  have indicated above. there are diseases,that  a person is born with, for example, a baby may have a defective heart at the time of its birth. Then t

Palaeontological evidence, Palaeontological Evidence: Palaeontology  ...

Palaeontological Evidence: Palaeontology  is a branch of  earth sciences, which is essentially a study of plant and animal life in the past geological periods, millions of ye

Accident reporting procedure, Accident Reporting Procedure : It is better ...

Accident Reporting Procedure : It is better to use incident book and accident report forms for the purposes of keeping records of accidents. The incident book is to be maintained

Enivronment, which is the probable principal source of nitrates and phospha...

which is the probable principal source of nitrates and phosphate a. the water cycle b. nitrogen fixation c. bacterial decay d. change in environmental temperature e. changes in lig

What is the greenhouse effect, Q.What is the greenhouse effect? Some gas...

Q.What is the greenhouse effect? Some gases like carbon dioxide, methane, nitrous oxide prevent the escape of heat from the Earth's surface by trapping it. This increases the av

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