Słowo ścieżka ma tu znaczenie tego rodzaju- tak sądzę. Linki zostaną dodane.

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Note added at   38 min (2015-05-30 19:28:38 GMT)
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Mówimy o szlakach/ ścieżkach metabolicznych (biologicznych) - zatem SZLAK stanowi swego rodzaju alternatywę lecz osobiście -jeśli dobrze rozumiem ten konkretny kontekst- użyłbym pojęcia nadrzędnego- zatem obszar.

[...]
pathway /path·way/ (path´wa)
1. a course usually followed.
2. the nerve structures through which an impulse passes between groups of nerve cells or between the central nervous system and an organ or muscle.
3. metabolic p..

http://medical-dictionary.thefreedictionary.com/pathway

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Note added at   42 min (2015-05-30 19:33:08 GMT)
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Warto pamiętać że'pathway' (przy tak ogromnej ilości znaczeń zależnie od kontekstów medycznych) oznacza ścieżka/ przejście (w pewnym sensie dobre słowo) ALE I sieć neuronów przekazujących sobie informacje).
Zatem- sieć/ szlak/ obszar- coś w tym kierunku - czyli jakieś rozwiązanie pośrednie.

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Note added at   1 godz. (2015-05-30 20:04:57 GMT)
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Jeszcze mie przyszedł do głowy taki zwrot" główny/ podstawowy patologicznie zmieniony "dostęp/ patologicznie zmieniona droga dostepu" (celowo w nawiasie) - ale PONOWNIE jako kierunek czyli posród szeregu zwrotów wśród których należałoby znaleźć ten wypośrodkowany.

There are many nasal conditions which require treatment. One such condition is nasal inflammation, specifically rhinitis, which can be allergic or non-allergic and is often associated with infection and prevents normal nasal function. By way of example, allergic and non-allergic inflammation of the nasal airway can typically effect between 10 and 20 % of the population, with nasal congestion of the erectile tissues of the nasal concha, lacrimation, secretion of watery mucus, sneezing and itching being the most common symptoms. As will be understood, nasal congestion impedes nasal breathing and promotes oral breathing, leading to snoring and sleep disturbance. Other nasal conditions include nasal polyps which arise from the paranasal sinuses, hypertrophic adenoids, secretory otitis media, sinus disease and reduced olfaction. In the treatment of certain nasal conditions, the topical administration of medicaments is preferable, particularly where the nasal mucosa is the prime pathological pathway, such as in treating or relieving nasal congestion. Medicaments that are commonly topically delivered include decongestants, anti-histamines, cromoglycates, steroids and antibiotics. At present, among the known anti-inflammatory pharmaceuticals, topical steroids have been shown to have an effect on nasal congestion. Topical decongestants have also been suggested for use in relieving nasal congestion. The treatment of hypertrophic adenoids and chronic secretory otitis media using topical decongestants, steroids and anti-microbial agents, although somewhat controversial, has also been proposed. Further, the topical administration of pharmaceuticals has been used to treat or at least relieve symptoms of inflammation in the anterior region of the nasopharynx, the paranasal sinuses and the auditory tubes.
http://www.google.com/patents/WO2013124493A1?cl=en