7) Digital flexors of the forelimb, pronators of the radioulnar joint

Transcription

1 Anatomy 1 - Lesson XI: Myologia- Part II Objective: Students will examine the muscles of a canine in order to identify the musculature of the body Practical Tasks 6-10: 6) Carpal flexors, pronators of the radioulnar joint 7) Digital flexors of the forelimb, pronators of the radioulnar joint 8) Carpal extensors, supinator of the radioulnar joint 9) Digital extensors of the forelimb, supinator of the radioulnar joint 10) M. sternocleidomastoideus, m. omotransversarius Practical Task 6: Carpal flexors & Pronators of the radioulnar joint

2 Fasciae antibrachii (from tensor fasciae antibrachii) is covering everything, save a little piece somewhere or just say that it covered all parts. Remove the rest of the fasciae Start cranially on medial side. You will find pronator teres Take next one caudally, trace it under the carpal retinaculum. It s the flexor carpi radialis Take next one caudally. Trace the huge tendon and free it from the flexor retinaculum, it divides into four branches and is the superficial digital flexor Lift it and you will find the deep digital flexor. Start the dissection of the deep digital flexor distally. Free it from the carpal tunnel. Grab the common tendon of the deep digital flexor distally and by using your fingers, separate the three main heads, the radial, the ulnar and the humeral head. The ulnar is the smallest and deepest one. The humeral head consists of three but you don t have to care about it, just know it, and they are all inserted on the medial epicondyle, just on slightly different spots. The next one is the flexor carpi ulnaris, Separate the two heads, the ulnar is the smaller. Between radius and ulna is the pronator quadratus located.

3 Practical Task 7: Digital flexors of the forelimb, pronators of the radioulnar joint Start cranially on medial side. You will find pronator teres Take next one caudally. Trace the huge tendon and free it from the flexor retinaculum, it divides into four branches and is the superficial digital flexor Lift it and you will find the deep digital flexor. Start the dissection of the deep digital flexor distally. Free it from the carpal tunnel. Grab the common tendon of the deep digital flexor distally.. Between radius and ulna is the pronator quadratus located.

4 Practical Task 8: Carpal extensors, supinator of the radioulnar joint

5 Fasciae antibrachii (from tensor fasciae antibrachii) is covering everything, save a little piece somewhere or just say that it covered all parts. Remove the rest of the fasciae Start with the most cranial muscle and trace it distally. You will find the insertion on Mc 1+2. That tells you that this is the extensor carpi radialis Pick up the next muscle laterally to it. Trace it. It goes under the extensor retinaculum and divides in four branches = The common digital extensor. Most caudally of the extensors, you will find the extensor caroi ulnaris (also called ulnaris lateralis). It s inserted partly to the accessory carpal bone and mainly to mc 5. Go between the common digital flexor and the lateral digital extensor and you will find the supinator. If your dog has the brachioradialis is it located on the surface of extensor carpi radiale. Practical Task 9: Digital extensors of the forelimb, supinator of the radioulnar joint

6 Fasciae antibrachii (from tensor fasciae antibrachii) is covering everything, save a little piece somewhere or just say that it covered all parts. Remove the rest of the fasciae Start with the most cranial muscle. Separate it carefully and stop when you can see a tendon crossing your first muscles tendon. Trace the crossing tendon, it ends on the first digit and tells you that this is the abductor digiti I longus it s going under the extensor retinaculum (you have to cut it) Go back till the muscle you started with and trace it distally. You will find the insertion on Mc 1+2. That tells you that this is the extensor carpi radialis Pick up the next muscle laterally to it. Trace it. It goes under the extensor retinaculum and divides in four branches = The common digital extensor. Grab the next muscle and trace it (running under the extensor retinaculum)it divides into three parts= The lateral digital extensor Most caudally of the extensors, you will find the extensor caroi ulnaris (also called ulnaris lateralis). It s inserted partly to the accessory carpal bone and mainly to mc 5. Go between the common digital flexor and the lateral digital extensor and you will find the supinator. Lift the common digital extensor and you can find, on the medial surface, the very small branches of the extensor pollicus et indici. You can try to separate it from the common digital extensor but it s VERY tiny. (Do it when no teacher is there, they can forget it if you are lucky). The muscle belly is hidden by the common digital extensors belly. If your dog has the brachioradialis is it located on the surface of extensor carpi radiale.

7 Practical Task 10: M. sternocleidomastoideus, M. omotransversarius

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9 Start with some carefully cleaning. Be careful, the muscles are very thin and do not hurt the jugular vein. It s running on the surface of sternocephalicus and is a good landmark- Above is the cleiocephalicus. Trapezius (pars cervicalis) goes from the spina scapulae, carfully separate it from the cleiodocervicalis and you will find the omnotransversarius ventrally to it, also attached to the spina scapulae. You will see a triangle between trapezius, cleidocervicalis and omnotransversarius. Keep it as a landmark. Start clean on cleidocervicales (The fibres runs up to the neck). Clean carefully around the jugular vein and lay bare it (draw it ventrally so you get rid of it). After cleaning and moving of the jugular vein, a border between cleidocervicalis and sternocephalicus is visible (It s very thin) and transparent. Separate the cleidocervicalis from the sternocephalicus. Clean cleidocervicalis against its insertion. Stretch the leg and find clavicular intersection ( a small transparent band, put your finger under it to show) The part belox is cleidobrachialis, its insertion is deep and do not have to be shown. The parts above is the cleidocervicalis and cleidomastoideus Go to veina jugulare. Between its to branches, you will find the mandibular gland. Cut around it (but not at is cranial border) and reflect it cranially. By doing it, you will find the tendon of sternomastoideus. ( and also os cleidomastoideus but you cannot be sure yet) Go back to omnotransversarius and trace it under cleiodiocervicales (you can now clean the triangle from fat and lymph nodes). Grab cleidocervicales (Or transect it) and reflect it (but it s not transected) and you will see the not so evident separation between the clediocervicales and cleidomastoideus. Do an incision between trapezius and cleidocervicales to easier reach the deep muscles. Stop trace omnotransversarius a few centimeters from atlas. Make a distinct incision between sternocephalicus and cleidocephalicus and you will see more of omnotransversarius. (Between) Cleidomastoideus is below sternooccipital. Now is cleidomastoideus founded and you can clean the insertionpoint and see the both mastoid muscles insertions. You can now also separate the sternooccipital from the sternomastoid if you want to but it s not necessary. 1. Clean startingpoint 2. Find insertionpoints 3. Clean and trace omnotransversarius to find everything because omnotransversarius is the deepest in this topic!