arrector


Also found in: Dictionary, Thesaurus, Encyclopedia.
Related to arrector: hair follicle

arrector

 [ah-rek´tor] (pl. arrecto´res) (L.)
raising, or that which raises; an erector muscle.

e·rec·tor

(ē-rek'tŏr),
1. One who or that which raises or makes erect.
2. Denoting specifically certain muscles having such action.
Synonym(s): arrector
[Mod. L.]

arrector

/ar·rec·tor/ (ah-rek´tor) pl. arrecto´res   [L.] raising, or that which raises; an arrector muscle.

e·rec·tor

(ĕ-rek'tŏr)
1. One who or that which raises or makes erect.
2. Denoting specifically certain muscles having such action.
Synonym(s): arrector.
[Mod. L.]

arrector

pl. arrectores [L.] raising, or that which raises; an erector muscle.

arrector pili muscle
smooth muscle that extends from the papillary zone of the dermis to the base of a hair follicle. Involuntary contraction causes hair erection which, in some species, is most noticeable on the neck and along the back (see hackles).
References in periodicals archive ?
Contrary to the other synapomorphies listed above, the arrector dorsalis not subdivided into different sections (22: 1 [right arrow] 0) and the dorsomesial limb of posttemporal (or posttemporo-supracleithrum) not markedly thin and mesially extended (88: 0 [right arrow] 1) were not proposed as potential cypriniform synapomorphies in previous works.
Regan, 1911; Chardon, 1968; Roberts, 1973; Lundberg, 1975; Howes, 1983ab; Fink & Fink, 1981, 1996; Arratia, 1987; Schaefer, 1990; Mo, 1991; Arratia, 1992; De Pinna, 1993, 1998; Diogo, 2004) but others seemingly constitute additional potential synapomorphies to diagnose the order, such as: arrector dorsalis not subdivided into different sections (22: 1 [right arrow] 0); frontal and autopterotic not contacting in dorsal view (48: 0 [right arrow] 1); absence of 'ligament between posttemporal and posterior margin of neurocranium' (92: 0 [right arrow] 1); presence of coracoid bridge (103: 0 [right arrow] 1); adductor mandibulae attaching exclusively on mandible and/or primordial ligament, near its mandibular insertion (111: 1 [right arrow] 0).
One of the main reasons for this is precisely due to the presence, in catfishes, of the muscle 'arrector 3', which was not described by Winterbottom and was tentatively named arrector ventralis by Diogo et al.
Significant part of mesial portion of arrector ventralis.
Arrector ventralis divided into two distinct, well-developed bundles widely separated by large horizontal lamina of coracoid (or scapulo-coracoid).
Each hair is attached to small muscles called arrector pili muscles.
Surge arrectors and control valves are discussed in Section C-7.