the mucous membrane lining them produces mucus

[Couch Tomato]

Several bones of the skull contain air-filled chambers
called sinuses. Sinuses have two major functions: (1) They
make a bone weigh less than it would otherwise, and (2) the
mucous membrane lining them produces mucus that moistens
and cleans the air in and adjacent to the sinus.
(Fundamentals of Anatomy & Physiology - Frederic H. Martini, Ph.D. & Judi L. Nath, Ph.D.)

Does the underlined part make sense to you? Am I right in saying that "them" should be omitted? It doesn't make sense to me with "them".

Thank you in advance.

 

[Beryl from Northallerton]

(2) the mucous membrane lining the sinuses produces mucus that moistens and cleans the air in and adjacent to the sinus. ('lining' is the present participle of 'to line')

 

[entangledbank]

'Lining' here is a verb; it's equivalent to 'the mucus membrance which lines them (the sinuses) produces mucus'. You could indeed leave out 'them' and take 'lining' for a noun, modified by 'mucous membrane', and I think the noun phrase 'the mucous membrane lining' makes perfectly good sense in this sentence.

 

[Couch Tomato]

Thank you, Beryl and entangledbank.

 

[bicontinental]

Does the underlined part make sense to you? Am I right in saying that "them" should be omitted? It doesn't make sense to me with "them".

For the sake of clarity I think you need to word it as the authors have done. By leaving out 'them' you end up with 'the mucous membrane (lining) produces mucus.' But the sinuses are lined by this mucous membrane, and this information is lost if you leave out 'lining them'.

It wouldn't be wrong to say 'the mucous membrane lining' as a noun phrase, but it seems a tad redundant as the mucous membrane is a lining, therefore, 'the mucous membrane produces mucus...' would suffice.

Bic