Year 12s: what will be the first way you research your future options? >>

Homeostasis

SBizzy

How do nervous and chemical responses differ

Reply 1

TJ-2002

nervous responses are faster than chemical responses
chemical responses last longer than nervous responses

Reply 2

absolutelysprout

moving to biology :smile:

Reply 3

That'sGreat

Original post by SBizzy

How do nervous and chemical responses differ

I'm in Year 13 biology and I've got no clue. ****.

Reply 4

SBizzy

Original post by That'sGreat

I'm in Year 13 biology and I've got no clue. ****.

Loooooool

Reply 5

Jpw1097

Original post by SBizzy

How do nervous and chemical responses differ

Nervous responses uses the nervous system - these responses are much quicker than hormonal responses and tend to be short-lived. Also, these responses tend to affect a specific organ/tissue. However, chemical responses use hormones which circulate in the blood and therefore are much slower than nervous responses and can affect many different organ systems. Since hormones circulate in the blood for a while, these responses tend to last much longer than those produced by the nervous system.

Reply 6

macpatgh-Sheldon

Hi,
@SBizzy

JPW's answer covers most of the relevant points. I would interpret your Q in a slightly broader scope in that chemical responses technically should not be confined to hormonal ones. One could argue that responses of the body to changes in oxygen concentrations, H+ and OH- ions [so acid-base status] as well as chemotactic responses whereby certain inflammatory cells are attracted to sites where they are needed via the action of cytokines can also fall under the classification of chemical mediators. Other chemicals with important physiological/homeostatic functions include the prostaglandins with their crucial role in the maintenance of temperature [and of course, our human intervention in the use of drugs that block cyclo-oxygenase e.g. ibuprofen to treat pain and pyrexia].

Hormones are exclusively either proteins e.g. the 51 amino acid polypeptide insulin (broken off from the 86 a.a. pro-insulin) OR steroids e.g. the adrenal cortical hormones and the sex hormones. The substances mentioned in italics above are heterogeneous in chemical composition - having said all this, JPW's analysis of hormonal action also for the most part applies to these other chemical responses, except perhaps in certain instances of allergic reaction (Type I or immediate-type hypersensitivity reaction) where an anaphylactic reaction brought about by chemical agents such as histamine and arachidonic acid in conjunction with IgE can spark off a very quick and as it happens, quite catastrophic set of events, sometimes fatal. (Admittedly, this does not fit your title of homeostasis).