90 LABORATORY MANUAL OF HUMAN ANATOMY 



ica. Observe the communication of the deep veins with these super- 

 ficial veins. 



Arteries. 



(a) Dorsal metacarpal and cutaneous rami of dorsal digital arteries 

 (Aa. digitales dorsales, Aa. metacarpeae dorsales). 



Deep Fascia. 



Remove all remaining fat of superficial fascia, so as to clean 

 carefully the deep fascia of the forearm and back of the hand. 



(a) Deep fascia of forearm (fascia antibrachii) . 



How is it related to the fascia brachii? What becomes of it 

 below? Note the relation of the lacertus fibrosus to this fascia. 

 Look closely at the fibres composing the fascia and note their direc- 

 tion. What nerves and blood-vessels perforate the fascia on the 

 volar and dorsal surfaces of the forearm? Besides those already 

 mentioned find (1) ramus cutaneus palmaris N. ulnaris, (2) ramus 

 palmaris N. mediani, and (3) ramus superftcialis N. radialis. (See 

 Fig. 24.) 



(b) Deep fascia of back of hand (fascia dor sails manus). 



Is it as thick as the fascia antibrachii? Note its attach- 

 ment proximalward to the ligamentum carpi dorsale and 

 distalward to the fibrous sheaths of the extensor tendons. 

 The deeper connections of the fascia may be studied later. 

 (ba) Dorsal ligament of the wrist (Lig. carpi dorsale) (0. T. 

 posterior annular ligament). What are its relations proxi- 

 malward and distalward? Ascertain exactly its attach- 

 ments to the radius. What becomes of the ligament ulnar- 

 ward ? 



Radial Artery and its Relations in the Forearm (A. radialis). 



Turn aside the ramus volaris of the N. cutaneus antibrachii 

 medialis, the N. cutaneus antibrachii lateralis, and the super- 

 ficial veins. Dissect off the fascia antibrachii, but take care not 

 to disturb the nerves going to the palm. Where muscle-fibres 

 arise from its deep surface, do not remove the fascia. Note care- 

 fully the attachments of the fascia antibrachii in the depth. Dis- 

 sect out the radial artery and its branches in the forearm, clean- 

 ing the adjacent muscles, but disturbing the relations as little as 

 possible. Where does the artery begin? Note exact relations 

 to various muscles in different parts of its course. Between 

 what tendons does that portion of the artery usually palpated 

 in taking the pulse lief Note the relations of the radial artery 

 to the radial veins (Vv. radiates) and to that part of the super- 

 ficial ramus of the radial nerve beneath the fascia antibrachii. 

 Study the origin and distribution of the following branches : 



