Could you please help me to analyze the functions of the italicized words in the following texts?

a)Patient: Doctor, I am so nervous. This is my first operation.

Surgeon: I know how you are feeling. You are my first patient.

b) Tourist: I clearly had the right of way when this man ran into me, and yet you say I was to blame.
Local Officer: You certainly were.
Tourist: Why?
Local Officer: Because his father is Mayor, his brother is Chief of Police and I go with his sister."