The professor then open the blanket and slowly poke his finger deeply to the dead body's anus, spin the finger and suck it right in front of the students.
The professor said to everyone "do it Hurry!"
The students are all feeling very disgusting with the bizarre example but they all decide to do it just to satisfy the professor.
After everyone is done, the professor strongly stare at everyone and said out loud.
The students did not realize that the doctor use different finger so they all got fooled by him and suck the finger they use to poke the anus (yuck!!)
Anatomy = The science of body structure and organism
Surgery = Medical Operation
Disgusting = Highly offensive with something
Poke = Push or jab
Bizarre = Extremely unconventional style or manner
Observant = Quick to perceive or apprehend
Middle finger = Second finger between index finger and ring finger
Index finger = Finger next to thumb
Some sources from http://www.thefreedictionary.com