Accessing the Body of a Function with Lua

I'm going back to the basics here but in Lua, you can define a table like so:

myTable = {}
myTable [1] = 12

Printing the table reference itself brings back a pointer to it. To access its elements you need to specify an index (i.e. exactly like you would an array)

print(myTable )    --prints pointer
print(myTable[1])  --prints 12

Now functions are a different story. You can define and print a function like so:

myFunc = function() local x = 14 end     --Defined function
print(myFunc)                            --Printed pointer to function

Is there a way to access the body of a defined function. I am trying to put together a small code visualizer and would like to 'seed' a given function with special functions/variables to allow a visualizer to 'hook' itself into the code, I would need to be able to redefine the function either from a variable or a string.