How to Access Treeview Child Nodes

Hello, I am using the treeview control for the first time. My tree view is populated with parent and child nodes already.

I'm trying to locate a specific child node so that I can update the text. I have attached a screen print of my treeview.

When I execute the following code only the 4 parent nodes of "Main", "Request Info", "Business Only", and "PHI Data" are detected(see attached screen print). I can't seem to figure out how to get to the children of the parent nodes.

 
For intX = 0 To FrmCreateCQSummary.tvSummary.Nodes.Count - 1
    If FrmCreateCQSummary.tvSummary.Nodes(intX).Name = "NodeAssignedTo" Then
       FrmCreateCQSummary.tvSummary.Nodes(intX).Text = FrmCreateCQSummary.tvSummary.Nodes(intX).Text & " " & assignedToStr
     End If
Next 

How can I get to the childnode of "NodeAssignedTo" to update the text via code? I will also need to access the children of the Child node titled "Description" (see screen print). Any pointers will be greatly appreciated. Thanks!