# Anatomy. Upper Extremities Muscles and anatomy of axilla. Tiba Al-Ani 9/10/2015 Nabil. Page 0 of 16

Transcription

1 #10 25 Anatomy Upper Extremities Muscles and anatomy of axilla Tiba Al-Ani 9/10/2015 Nabil Page 0 of 16

2 Salam AWN Today s lecture is divided into two parts, the first part is the continuation of the upper extremities muscles and the second part is about the anatomy of the Axilla. I wrote the information differently from the record to avoid repetition and to make the information more organized. Good luck with this lecture Page 1 of 16

3 Upper extremities Muscle Last lecture we started talking about the upper extremities muscles and today we will continue with compartments of the arm and then we will move to the forearm and it s compartments. skin Fascia Humerus Lateral intermuscular septum Medial intermuscular septum Neurovascular bundle - As you can see in this transverse section there are 2 compartments and there is an aponeurotic sheet separating various muscles within the compartment. - Theses muscles are located anteriorly and posteriorly. - Anterior compartment: are flexor and act upon the forearm except the Coracobrachialis which act upon the shoulder. Posterior compartment: are extensor and work upon the forearm only. And there is a small lateral compartment that has a neurovascular structure. As we look from outside to inside we can see: skin Fascia Humerus Page 2 of 16

4 Fascia that covers the muscle in any compartment will play a very important role in separating the action of the muscles. Fascia that surrounds the muscle keep the muscle in tension and in this transverse section it goes to the medial and the lateral border of the humerus and insert over there. It separates the muscle almost completely except for the ulnar nerve that passes from the posterior aspect of the arm into the posterior aspect medially to the forearm. MUSCLES OF FOREARM We said that in the lower extremities of the humerus we have lateral and medial epicondyle and those are very important for protrusion lateral and medial of the lower extremities of the humerus and provide the orgin of the muscle going to the forearm. - Anterior Compartment : Common orgin flexor that come from the medial epicondyle. We have superficial and deep muscles, they are not separated and they overlap but sometimes the deep muscle are divided into two subcompartments Superficial : 1. Pronator Teres 2. Flx. Carpi ulnaris 3. Palmaris Longus 4. Flx. Carpi Radialis 5. Flx. Digitorum Superficials This Muscle stay in the same level with the Flx. Pollicis Longus and practically they belong to the deep compartment Page 3 of 16

5 Deep: 1. Flx. Digitorum Profundes 2. Flx. Pollicis Longus 3. Pronator Quadratus Superficial muscles: - If you look at this picture don t confuse with the Brachloradialis, it s extensor, belongs to the posterior compartment and goes all the way to the back of the thumb. - From lateral to medial Flexor carpi radialis, palmaris longus, and flexor carpi ulnaris. - Palmaris longus has a different story, it comes from the medial epicondyle, it is a thin muscle and more superior than the other muscles, and all the muscles except the Palmaris Longus passes below the Flexor retinaculum where the Palmaris Longus passes above it. When Palmaris Longus passes above the Flexor retinaculum it will forms a traingular shape at the palm called Palmar aponeurosis and then Palmar aponeurosis divides and goes to the four digit and do attachment to the base of the four fingers. These ligaments that are send from the palmar aponeurosis to the fingers are called superficial transverse ligament of the palm. As you can see the Palmar aponeurosis covers most of the palmar surface between the thener and Page 4 of 16

6 the hypothenar group of muscles that are located below the thumb and the little finger. Flexor Retinaculum: a very thick aponeurotic membrane that holds the muscles in their position and also provide for each tendon of those muscles that comes from the forearm a tunnel. In addition it protect nerves that comes to the hand and protect certain arteries such as ulnar artery. Flexor Retinaculum has nothing to do with Palmaris Longus, it doesn t send any fascia or any attachment to Longus so the Longus is very mobile and superficial muscle and when you grab your hand you can palpate the muscle at the level of the wrist. - Pronator teres: it s the one located on the corner of the forearm and covered partially by the Biceptal aponeurosis. Page 5 of 16

7 Here is a table that contain the superficial muscles but the doctor didn t mention the nerve supply: Name of the muscle origin Insertion Action Nerve supply Flexor Carpi Radialis Flexor Carpi Ulnaris Flexor Digitorum Superficialis Pronator Teres Palmaris Longus Medial epicondyle of humerus Humeral head: Medial epicondyle of humerus; Ulnar head: olecranon and posterior border of ulna Humeroulnar head: medial epicondyle of humerus, ulnar Collateral ligament, and coronoid process of ulna; Radial head: superior half of anterior border of Radius Medial epicondyle of humerus and coronoid process of ulna Medial epicondyle of humerus Base of 2 nd metacarpal Pisiform bone, hook of hamate bone, and 5 th metacarpal bone Bodies of middle phalanges of digits 2-5 Middle of lateral surface of radius anterior aspect of the distal flx.retinaculu m and palmar aponeurosis Flexes and abducts hand (at wrist) Flexes and abducts hand (at wrist) Flexes middle phalanges at proximal interphalangeal joints of medial four digits; acting more strongly, it also flexes proximal phalanges at metacarpophalangeal joints and hand Pronates and flexes forearm (at elbow) flx.the wrist, and tightens the palmar.aponeurosis Median nerve (c6,c7) Ulnar nerve (c7,c8) Median nerve (c7,c8,t1) Median nerve (c6,c7) Median nerve (c6,c7) Page 6 of 16

8 Deep muscles: - I have taken this part from pulse sheet because I couldn t get what the doctor is saying: Flexor digitorum superficialis and Flexor digitorum profundus: insertion is before that of the profudus sertion of the prefunds is Base of the distal phalanx of digits 2-5, while the superfacialis insertion is Bodies of middle phalanges of digits 2 5. Tendons of the superfacialis will make a bifurcation or split so that it can pass on each sides of the tendons that belong to the profundus because the profundus tendon goes all the way down. And that s why the superfacialis has to have bigger and wider origin rather than other muscles so that it can provide more force for its tendons to produce it action. when you are flexing the distal phalynges of any digit you use the flexor digitorum profundus which is the more deep one. interphalangeal joints also notice the innervations (median nerve). This muscle goes to the Bodies of middle phalanges of digits 2 5. Page 7 of 16

9 Here is a table that contain the deep muscles but the doctor didn t mention the nerve supply: Name of the muscle origin Insertion Action Nerve supply Flexor Digitorum Profundus Pronator Quadratus Flexor Pollicis Longus Proximal 3/4 of medial and anterior surfaces of ulna and Interosseous membrane Distal 1/4 of anterior surface of ulna Anterior surface of radius and adjacent Interosseous membrane Base of the distal phalanx of digits 2 5 Distal 1/4 of anterior surface of radius Base of distal phalanx of thumb Flexes distal phalanges at distal interphalangeal joints of medial four digits; assists with flexion of hand Pronates forearm; deep fibers bind radius and ulna together Flexes phalanges of 1 st digit (thumb) Medial ulnar nerve (C8,t1) Lateral-AIN Of Median nerve (C8,t1) AIN (C8,T1) AIN (C7,C8,T1) Page 8 of 16

10 - Posterior compartment: Muscles of the posterior compartment originate from the lateral epicondyle of the humerus. Superficial : 1. anconeus 2.Brachioradialis 3.Ext.Carpi Radialis Longus 4.Ext.Carpi Radialis Brevis 5.Ext.Digitorum 6.Ext.Digiti Minimi 7.Ext.Carpi Ulnaris Deep: 1.Abductor Pollicis Longus 2.Ext.Pollicis longus 3.Ext.Pollicis brevis 4.Ext.Indicis 5.supinator Page 9 of 16

11 Here is a table that contain the superficial muscles but the doctor didn t mention the nerve supply: Name of the muscle origin Insertion Action Nerve supply Anconeus Posterior surface of the lateral epicondyle lateral surface of olecranon, body of ulna extension of forearm Radial nerve Brachioradialis prox.2/3 rd of lateral supracondylar ridge of humerus, lateral intermuscular septum Lateral aspect of distal radius just proximal to the styloid process acc.flexor of elbow Radial nerve (c5,c6) Ext. carpi radialis longus Lateral supracondylar ridge of humerus base of the 2 nd metacarpal bone extends and abducts the hand Radial nerve (c6,c7) Ext. carpi radialis brevis Lateral epicondyle of the humerus base of the 3 rd metacarpal bone extends and abducts the wrist Deep branch of radial nerve (c7,c8) Extensor digiti minimi Lateral epicondyle of the humerus extensor expansion of the 5 th digit ext.of 5 th digit at MC, PIP, ext of wrist when little finger in extension PIN (c7,c8) Extensor carpi ulnaris 2 heads: lateral epicondyle of humerus, Posterior border of ulna medial side of the base of the 5 th MC extends and adducts the hand PIN (c7,c8) Page 10 of 16

12 Here is a table that contain the deep muscles but the doctor didn t mention the nerve supply: Name of the muscle origin Insertion Action Nerve supply Supinator Lateral epicondyle of humerus, radial collateral ligament, annular ligament,supinator fossa, crest of ulna lateral,posterio r,anterior surface of prox 1/ 3 rd 0f radius supination Deep branch of radial nerve (c7,c8) Abductor pollicis longus upper parts of the posterior surface of the radius & ulna and interosseous mem. base of the 1 st metacarpal bone abducts,extends, lat.rotates the thumb at carpometacarpal joint, & abducts the wrist. PIN (C7,C8) Extensor pollicis brevis posterior surface of the radius below the origin ofabductor Pollicis longusand from interosseous mem. base of the prox.phalanx of the thumb extends poximal phalanx of the thumb at MC joint, extend at 1 st carpometacarpal joint PIN (C7,C8) Extensor pollicis longus posterior surface of middle 1/3 rd of ulna And interrosseous mem base of the diastal phalanx of the thumb extends distal phalanx of the thumb at MP joint,ip joint.and it can contribute abduction of the thumb PIN (C7,C8) Extensor indicis posterior surface of ulna m/3 rd below the EPL extensor expansion of the 2 nd finger ext of index finger and wrist. PIN (C7,C8) Page 11 of 16

13 Anatomical Snuff box: Lateral = E.pollicis brevis Medial = E. pollicis longus Floor = scaphoid, styloid of radius Contains branch of the radial artery (pulse) Carpal tunnel : It s a tunnel formed between the concavity of the carpal bones and a ligament covers it which is the Flexor retinaculam. Tendons of the flexors pass through, median nerve also passes through. It consider as a crowded tunnel. Carpal tunnel syndrome: Caused due to compression of the nerve in the tunnel. Causes: 1. Swelling of the tendond (overuse). 2. Pregnancy (edema) 3. Arthritis Symptoms: tingling or numbness-lateral part of the hand, weakness in the thumb movement. Treatment: rest, splinting, anti-inflammatory drugs,surgery (according to the doctor is the best method). Page 12 of 16

14 Now we will start with the second part of this lecture: Anatomy of the Axilla ribs). It s very important to know that the axilla is a place where most of the structure that goes from the thorax to the upper extremities pass through, such as arteries and brachial nerve. Its called armpit. The axilla is located medial to the surgical neck of the humerus and lateral to the lateral aspect of the thorax upper part (2 nd, 3 rd, 4 th, 5 th costal It has a triangular prymidal in shape which the upper part is smaller than the lower part and we have the apex which is the inlet and the base which is the outlet of the axilla. Page 13 of 16

15 as you can see here the armpit has two folds called axillary fold Anterior made by Pectoralis major, subclavius muscle which is very small and the clavipectoral fascia that covers the pectoral muscle. Clavipectoral fascia orginate from the inferior aspect of the clavicle and goes medially and split into two to hold the subclavius muscle, then it fuse back and again split to hold the pectoralis major muscle. The continuation of the clavipectoral fascia is axillary fascia. Posterior made by latissimus dorsi and teres major Medial wall is the upper thoracic wall and its made by the serratus anterior muscle that adhere to the 2 nd to 5 th rib. Floor is made of the skin. Superior in the entrance and the base closed by the skin. Many structure passes the axilla such as 3 rd part of the subclavian artery, brachial artery, brachial plexus which contain the radial and ulnar nerve. The lateral wall contain intertubercular sulcus, it usually fused with medial wall so sometimes we don t consider it as a lateral wall because the intertubercular ligament covers the intertubercular sulcus. Page 14 of 16

16 The inlet is located lateral to the margin of the ribs and the clavicle. As you can see in the previous figure there is an axillary sheet and also there is a pectoralis sheet which is not present in the figure. Pectoralis sheet is the continuation of the superficial sheet that covers the neck, the superficial sheet will go to the clavicle and will be attached superiorly and then go and split to what we call the Pectoralis sheet which is anterior and surrounds and hold the pectoralis major. The other sheet is the Axillary sheet which is continuation of the deep fascia of the neck, the deep fascia will surrounds the hiatus which contain the subclavian artery and brachial plexus, then the deep fascia will be attached to the posterior aspect of the pectoralis fascia and this what we call Axillary sheet. The End finally :P Page 15 of 16