Change of IP address of nameservers

[Guan Sin Ong]

If I change the IP address of my nameservers, do I need to update the
host record with Internic beside updating the domain info? Put it
another way, does the IP address of a nameserver "hardcoded" at the
Internic/root servers? 

I was thinking along this line which I am not sure whether it's correct
or not:

foo.com's nameserver is xyz.bar.com. The IP address of xyz.bar.com has
changed recently and the nameserver for bar.com is giving out the new IP
address of xyz.bar.com. The DNS info of foo.com does not need to be
updated with Internic because the root server will respond that the NS
record for foo.com is "xyz.bar.com", which can then be resolved by
bar.com nameserver correctly.

Am I right or wrong? The issue is whether the Internic/root server also
keep record of and give out IP addresses of nameservers.

GS