Hi Klotyl, The coroner has asphyxiation as the cause of
death(,) from a crushed windpipe and…fractured dislocation of the cervical
vertebrae.
How I (native English speaker) understand/feel the use of (the) articles
here: it's true that there's only one windpipe, but the overriding reason for
“a” here is “first mention” (of the crushed windpipe).
The cervical vertebrae: there are two reasons here for
“the”. (1) “Assumed context”: we are talking about the
vertebrae that (everyone knows) are present in the human body; (2) we want to
define which vertebrae we mean – the cervical vertebrae, not the lumbar
vertebrae, not the thoracic vertebrae. “Asphyxiation as cause of death” (no
article before “cause”) is also possible, but less likely – Ngram.
If the writer omits the article in front of “cause”, it's because (a) he is
considering “cause of death” something like an item in a list, such as
“name”, “sex”, “date of birth”, “date of death”, “cause of
death” (and in that kind of usage articles are usually omitted) or (b) he
consider's “cause of death” as a kind of “abstract concept”. Cause
(and death, too, for that
matter) can be countable or uncountable. “Asphyxiation as a
cause of death” is also possible if there was more than one cause of death.
But you have to look at every example in its full context.
“First mention” is a very strong (and usually overriding) marker for the
indefinite article, so we have to know the full context to
understand if the use of the article can be attributed to the “first
mention” reason or not.