Page 1 of 2: half life of rbc

docsa · Credits: 9033 My Scrapbook

whts the half life of rbc in stored bld??

if possible then reply with ref
thanx
docsa

hardcoremallu · Credits: 14657 My Scrapbook My Reading List 6 Books

does half life means shelf life?
soory for this stupd question
i cant find specific half life of RBC

anyone with answers

docsa · Credits: 9033 My Scrapbook

sorry 4 a very vague q.

to be more precise---
normal life of rbc = 120 days
whn stored bld is transfused n rbc r in circulation life = ???
i m confused b/w 90 n 60 days

n
shelf life that is when not transfused ?? if any bdy has evr cameacross value 4 this

Actionking · Credits: 1838 My Scrapbook

Actionking · Credits: 1838 My Scrapbook

In order to calculate the answer you should know the number of rbc's produced by human body in a day

docsa · Credits: 9033 My Scrapbook

hi actionking
this q. is givn in one of the reputed dental mcq book
10-20 q. r directly picked frm this book
un4tun8tly this book has significant wrong ans.
they mention life of transfused rbc in circulation 90 days

but in NCERT BIOLOGY its mentioned = 60 days
n it appeared as the CBSE-PMT Q. this yr.

n i ve reffered few of med. books n i cudnt find any ref. thts y i m confused

docsa · Credits: 9033 My Scrapbook

Actionking · Credits: 1838 My Scrapbook

In humans let's assume that,

RBC production rate = RBC destruction rate R/day

Blood volume in a person V1/L
Blood volume taken from him/her for storage bag V2/L
Number of RBC in the human body=N
Totall amount of Rbc in the bag=n=N/V1 x V2

So, destruction rate of RBC in the bag=r
r=R/V1 x V2

Number of RBC in the bag
n/V1 x V2

Half amount of RBC in the bag n/2=N/2V1 x V2

T/ half = Half amount of RBC in the bag / r= R/V1 x V2

T/half = N/2V1 x V2 divided by R/V1 x V2

T/half = N/2 divided by R

T/half = N/2 x R

T/half = N / 2R

Now i hope you understand why production rate influences the T/half of RBC

docsa · Credits: 9033 My Scrapbook

i got ans to this finaaly.. its 60 days .. within 50-60 days transfussed RBC is sequestered by spleen

grandmaster · Credits: 4276 My Scrapbook

hi docsa
Firstly NCERT books are extremely reliable.So anything mentioned there is a straight answer
Secondly the concept of half life applies only to processes which :
1. progress in an exponential manner
2. the rate of progression is ALWAYS dependent upon the immediate number of participating particles
Since RBCs don't obey both of the above essential functions, the concept of half life doesn't aply to them

But of course half life applies t some other processes in the body for eg. Half life for gastric emptying is 30 minutes ( ref Laurence & Bennett pharmac )

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