166 PRACTICAL ANATOMY. 



1. The abductor minimi digiti muscle. 



2. The flexor brevis minimi digiti muscle. 



3. The opponens minimi digiti muscle. 



4. The two ulnar lumbricales muscles. 



5. The four dorsal interossci muscles. 



6. The three palmar interossei muscles. 



7. The adductor pollicis muscle. 



8. The inner head of the flexor brevis pollicis. 



THE RADIAL AND ULNAR ARTERIES IN THE HAND (Fig. 116). It now remains 

 to reduce to its simplest ten/is the blood-supply of the whole hand. 



The ulnar artery crosses the anterior annular ligament. Below the pisiform 

 bone it divides into (i) the superficial arch and (2) the deep ulnar branch. The 

 superficial arch crosses the palm, resting on the flexor tendons under cover of the 

 palmar fascia, and terminating by anastomosis in the superficial volar branch ot 

 the radial artery. From the arch are given off the first, second, third, and fourth 

 palmar digital branches that supply the second, third, fourth, and fifth fingers 

 with blood. (Fig. 116.) 



The radial artery passes to the back of the hand, under the three extensor 

 muscles of the thumb ; passes between the two heads of the first dorsal interos- 

 seous muscle ; crosses the palm beneath the flexor tendons, and terminates, by 

 anastomosis, in the deep ulnar artery. From this arch are given off five palmar 

 interosseous arteries. Three of these the three inner go to the clefts of the 

 fingers, where they unite with the palmar digital brandies from the superficial 

 palmar arch. The two outermost branches go to the thumb and index finger 

 under the special names of princeps pollicis and radialis indie is. (Fig. 1 16.) 



Carpal arteries are four in number: two from the radial artery the anterior 

 and posterior radial carpal ; two from the ulnar the anterior and posterior ulnar 

 carpal. 



The anterior and posterior perforating arteries communicate, through the 

 hand, with the dorsal interosseous arteries. These are arteries from an arch 

 formed on the back of the carpus by anastomosis between the radial and ulnar 

 posterior carpals. 



Where would von look for the cephalic vein in the vicinity of the shoulder .' 



Between the deltoid and pectoralis major muscles ; the vein is in a groove 

 with a small artery the descending branch of the acromio-thoracic artery. 

 (Fig. 105.) 



How and where do the superficial, radial, median, and ulnar veins terminate f 



They terminate opposite the elbow by changing their names. 



The radial above the elbow is called the cephalic vein. 



The ulnar above the elbow is called the basilic vein. 



The median breaks up near the elbow into the median basilic and cephalic. 



What are the voice comites f 



The two companion veins attending deep arteries in the extremities of the 

 body, below the knee and below the elbow. 



How do the superficial veins communicate with the veiue comites f 



By perforations in the deep fascia. By these communicating veins the circu- 

 ation internal to or below the deep fascia is equalized to the circulation external 

 to the deep fascia. 



If von were going to draw blood from a patient' s arm, wh\' would von select the 

 median cephalic vein in preference to the median basilic vein for venesection ' 



