196 LABORATORY MANUAL OF HUMAN ANATOMY 



(b) Occipital artery (A. occipitalis). 



(c) Posterior auricular vein (V. auricularis posterior). 



(d) Occipital vein (V. occipitalis). 



(e) Posterior auricular nerve (N. auricularis posterior). 



(ea) Occipital ramus (ramus occipitalis). 



(f) Posterior ramus of great auricular nerve (ramus posterior N. auric- 



ularis magni) . 



(g) Lesser occipital nerve (TV. occipitalis minor). 



(h) Great occipital nerve (TV. occipitalis major). (See Fig. 4, p. 47.) 



Muscles of the Scalp. 



Having isolated the blood-vessels and nerves, remove the rest 

 of the superficial fascia bit by bit, exposing the muscles of the 

 scalp; these and the aponeuroses are to be carefully cleaned. 

 Take care not to injure the muscles which move the ear ; expose 

 each muscle by putting it on the stretch. Write a description of 

 the course and distribution of the nerves and blood-vessels ex- 

 posed. Read the description given in your text-book of Sys- 

 tematic Anatomy of each vessel and nerve. How do the struct- 

 ures in your cadaver differ, if at all, from those described in 

 the text-book! Note the extreme vascularity of the scalp. It 

 is significant for the mobility and vitality of large flaps of de- 

 tached scalp. 



Study the exact origin and insertion and the innervation of 

 each of the following muscles : 



(a) Epicranius muscle (M. epicranius) (0. T. occipitofrontalis). 



(aa) Frontal muscle (M. frontalis). 



(ab) Occipital muscle (M. occipitalis). 



(aba) Procerus ("prolonged") muscle (If. procerus). 



Study the " aponeurotic helmet" (galea aponeu- 

 rotica) (0. T. epicranial aponeurosis). 



(b) Anterior auricular muscle (M. auricularis anterior) (0. T. attrahens 



auriculam). 



(c) Superior auricular muscle (M. auricularis superior) (0. T. attolens 



auriculam). 



(d) Posterior auricular muscle (M. auricularis posterior) (0. T. retrahens 



auriculam ) . 



Approximate the origin and insertion of each muscle so as 

 to understand clearly its action. 



Dangerous Area of the Scalp. 



Make an incision from four to eight centimetres long in the 

 galea aponeurotica in the middle line at the vertex; at right 

 angles to this make a short transverse incision. Lift the corners 

 of the flaps with forceps and note the loose areolar tissue, free 



