126 SPECIAL ANATOMY. 



147. 2. Fibro-cartilagmous portions, pulleys, (trochlese), and 

 grooves, on which the tendons in several places glide, to prevent 

 friction, firmly attached by both extremities to the bones. 



148. 3. Serous structures on the tendons, to assist their free 

 movement over bones, cartilages, &c. There are: 



a. Mucous sacs, bursce mucosa, 1. synaviales, generally closed sacs, which 

 lie between the muscles and bones, and connected with both, particularly over 

 joints, into which they frequently open ; e. g., on the m. subscapular of the 

 shoulder joint. 



b. Mucous sheaths, vagina mucosce s. synoviales, long (closed) sacs, through 

 which a canal passes for a free tendon, with which it is connected ; e. g., Biceps 

 brachii. 



I. Muscles on the Head. 



A. Muscles of the Cranium, Occipito-frontalis s. Epicranius. 



149. 1. Occipitalis, Occipital muscle. 



Shape: obliquely four-sided, weak. Position: close beneath 

 the skin of the occipital region. Origin from Unea semicircular, 

 superior, extending from close to the middle line to the base of 

 proc. mastoid. Insertion : Galea aponeurotica. Action : draws 

 the skin of the head backwards, rendering the forehead smooth. 



Nerves: supraorbital, supra and infra trochkat.^ rr. temporal. n.facialis. 



150. "2. Front alis, Frontal muscle. 



Shape: obliquely four-sided, above arched, flat. Position: close 

 beneath the skin of the forehead, from the root of the nose to the 

 frontal eminence. Before the Glabella the internal borders of 

 both meet together. Origin : root of nose and arcus superci- 

 liaris. Insertion: Galea aponeurotica. Action: elevates the 

 skin of the forehead and eyebrows (making transverse wrinkles), 

 stretches the skin of the back of the nose (by means of the so- 

 called procerus mm). 



Nerves : occipital major, and min. auricular, post. 



Galea aponeurotica, that is, the tendinous cap which lies be- 

 tween the two occipital and frontal muscles, formed of their tend- 

 ons, attached besides to the root of the proc. mastoid. to the 

 zygomatic arch as far as the external angle of the eye, intimately 

 united with the skin of the head (less with the periosteum), co- 

 vered with fat (in which are many nerves and vessels). Behind 

 it is thick and brilliantly white, on the sides thinner. 



