A TTOLLENS A UREM—A TTRA HENS A UREM 431 



Insertion. — The deep surface of the skin at the middle of the e3'ebrow. 



Structure. — A small wisp of fleshy fibres, closely connected with the or])ital 

 portion of the orljicularis pal])ebrarum. It passes outwards, and at the same time 

 sli<jhtly U))wards and forwards, to the under surface of this muscle, and, diverging 

 slightly, its fibres pass between the interlacing fi])res of the orl)icularis and frontalis 

 to their insertion into the skin. 



Nerve-supply. — The temporal branch of the upper division of the facial nerve, 

 whicli tenters its deep surface from the outer side. 



Action. — To draw the middle of the eyel)row inwards and slightly downwards. 

 In the adult this causes vertical wrinkles to form between the evebrows, and gives 

 a frowning aspect to the face, as when a difficulty occurs either in thought or action. 

 In the crying infant, the effect of its contraction is to cause dimples about the 

 centre of the eyebrows, which may usually be observed just before the orbiculares 

 pal})ebrarum close the eyes. 



Relations. — Superficially, the orbicularis palpebrarum ; deeply, the frontal bone. 



For The Muscles of the Eye, see pages 854-7. 



THE EXTRINSIC MUSCLES OF THE AURICLE 



The extrinsic muscles of the auricle (fig. 309) — viz. the attollens aurem, 

 the attrahens aurem, and the retrahens aurem — are feeble, and almost vestigial 

 in man. They are closely connected Avith the occipito-frontalis. The largest of 

 the three is the attollens aurem. 



1. ATTOLLENS AUREM 



The attollens aurem — named from its action as an elevator of the avuicle — is 

 a thin triangular sheet. 



Origin. — The epicranial aponeurosis, a short distance Ijelow the top of the 

 temj)oral ridge. 



Insertion. — The inner surface of the pinna of the auricle, over a space which 

 corresi)onds to the fossa of the antihelix upon its outer surface. 



Structure. — A thin, fan-shaped sheet, consisting of muscular fibres and bands 

 of connective tissue, which all converge from above upon a flat tendon just above 

 the point of insertion. 



Nerve-supply. — The temporal branch of the upper division of the facial nerve, 

 by filaments which enter the front of the deep surface. 



Action. — To draw upwards the auricle. 



Relations. — Superficially, the skin; deeply, the temporal fascia and auriculo- 

 temptn-al nerve. 



2. ATTRAHENS AUREM 



Tlie attrahens aurena — named from its action in drawing forwards the auricl» — 

 is a smaller and very thin triangular sheet. 



Origin. — The lateral border of the epicranial aponeurosis in front of and below 

 the level of the preceding, with which it is usually continuous. 



Insertion. — The front of the inner surface of the helix. 



Structure. — It consists of a thin stratum of muscular fibres, intermingled with 

 comiective tiss'ue, lying upon the temporal fascia, and converging backwards and 

 downwards upon a feei)le flat tendon. 



Nerve-supply. — The same as the preceding. 



Action. — To draw forwards and upwards the auricle. 



Relations. — Superficially, the skin; deeply, the temporal fascia, temporal 

 artery, and auriculo-temporal nerve. 



