Dr Matthew Lyall said there was also evidence that Liam Deane had suffered injuries to his brain due to a lack of oxygen.
-> Aftershave bottle used to inflict fatal injuries 'may have slipped through Leeds prison security'The doctor also told Leeds Crown Court that there was evidence that Deane had taken the synthetic cannabis drug spice prior to his death.
John Westland is on trial accused of murdering Deane in their shared cell at the Leeds prison on November 12 last year.
He pleads not guilty.
Deane was covered in blood when he was found dead by prison officers on the top bunk of his cell after Westland pressed an emergency buzzer.
A broken aftershave bottle was found on the floor of the cell which contained Westland's fingerprints.
-> Prisoner used smashed aftershave bottle to murder cellmate at Leeds prison, court toldDr Lyall told the court: "In my opinion the injuries to the left cheek, back of the head and scalp could certainly have been caused by the broken aftershave bottle found in the prison cell."
The pathologist said spice was present in urine and blood samples taken from Deane but it was not possible whether he was "suffering any toxic effects" at the time of his death.
Jurors have been told Westland will contend that he was not responsible for assaulting Deane and that his cellmate died as a result of self-inflicted injuries.
The court heard Westland may also contend that Deane died as a result of taking the drug spice.
The trial continues