64 LABORATORY MANUAL OF HUMAN ANATOMY 



(ab) Thoraco-acromial artery (A. thoraco-acromialis) (0. T. 



acromiothoracic or thoracic axis). 



(ac) Lateral thoracic artery (A. thoracalis lateralis) (0. T. long 



thoracic). 

 (aca) External mammary rami (Er. mammarii externi). 



(ad) Subscapular artery (A. sub scapular is). 



(ada) Thoracodorsal artery (A. thoracodorsalis) . 



(adb) Circumflex artery of scapula (A. circumflexa 



scapulae) (0. T. dorsalis scapulae). 



(ae) Anterior circumflex artery of humerus (A. circumflexa 



humeri anterior). 



(af) Posterior circumflex artery of humerus (A. circumflexa 



humeri posterior) . 

 Veins. 



(a) Axillary vein (V. axillaris). (Spalteholz, Fig. 492.) 



(aa) Lateral thoracic vein (V. thoracalis lateralis}. 



(aaa) Thoraco-epigastric vein (V. thoraco-epigastrica). 



(aab) Costo-axillary veins (Vv. costo-axillares). 



(ab) Brachial veins (Vv. brachiales). 



(ac) Cephalic vein (V. cephalica). 



(aca) Thoraco-acromial vein (V. thoraco-acromialis). 



(ad) Other tributaries corresponding to branches of axillary 



artery. 

 Nerves. 



At this stage of the dissection the relation of a group of nerves 

 to the A. axillaris should be closely observed, the full study of the 

 brachial plexus and its branches being made a little later. Note 

 then the relations of 



(a) Ulnar nerve (N. ulnaris). 



(b) Medial cutaneous nerve of upper arm (N. cutaneus brachii me- 



dialis) (0. T. lesser internal cutaneous, or nerve of Wrisberg). 



(c) Medial cutaneous nerve of forearm (N. cutaneus antibrachii me- 



dialis) (0. T. internal cutaneous). 



(d) Radial nerve (N. radialis) (0. T. musculospiral). 



(e) Axillary nerve (N. axillaris) (0. T. circumflex). 

 (/) Median nerve (N. medianus), with its two heads. 

 (g) Musculocutaneous nerve (N, musculocutaneus) . 



Shape and Boundaries of Fossa Axillaris. 



Describe the form of the fossa. What is the position of its 

 apex? How many walls has it? What structures help to form 

 the anterior wall ? What structures enter into the formation of 

 the posterior wall? Examine carefully the structures consti- 

 tuting respectively the medial and lateral walls of the fossa. 



Coracoclavicular Fascia (Fascia coracoclavicularis). 



Divide the pars clavicularis of the M. pectoralis major close 

 to the clavicle (leaving the pars sternocostalis for the present 

 intact) and reflect it downward and lateral ward, avoiding injury 



