 on muscles of the upper limb. In this session we will be revising all the muscles of the upper limb. So in this image we can see the right upper limb viewed from the anterior aspect. In this image the right upper limb is viewed from the posterior aspect. So in the upper limb muscle any muscle that we study we study under these headings. So we will try to cover these headings for each of the muscles of the upper limb. So let's start with the muscles of the pectoral region first. Muscles in the pectoral region there are four in number pectoralis major, pectoralis minor, subclavius and ceratus anterior. Let's start with the pectoralis major first. Pectoralis major proximal attachment it has got two heads of origin one is the clavicular head and other is the cernocostal head okay. Clavicular head arises from the anterior aspect of the medial half of the clavicle. Cernocostal head arises from the anterior aspect of the sternum as well as the costal cartilages as well as there is some attachment from the aponeurosis of external oblique muscle okay. Distal attachment it goes up to the lateral lip of the inter tubercula sulcus which is also referred to as bicepital groove okay. The nerve supply of pectoralis major is the medial pectoral nerve and lateral pectoral nerve. Then pectoralis minor muscle pectoralis minor arises from the third, fourth and the fifth ribs proximal attachment, distal attachment or insertion it goes up to the medial aspect of the corocod process of the scapula. The nerve supply is again by medial and the lateral pectoral nerve then action of pectoralis minor is it will help in protraction of the scapula along with ceratus anterior muscle okay. It also acts as an accessory muscle of respiration. Then subclavius muscle it is a small muscle a proximal attachment is from the first rib near the costochondral junction distal attachment is along the inferior surface of the clavicle in the subclavian groove. Nerve supply of subclavius is by the nerve to subclavius and action of subclavius is it will stabilize it will stabilize the shoulder girdle during movements of the shoulder joint okay. Now let's cover the axio appendicular muscles. Axio appendicular muscles as the name suggests it connects to the axial skeleton to the appendicular skeleton. So these are also referred to as muscles of the back which are included in upper limb. They are arranged in two layers of muscle one is the superficial layer and other is the deep layer okay. Superficial layer consists of trapezius and latissimus dorsi and deep layer consists of levator scapulae rhomboid minor and rhomboid major. Proximal attachment of trapezius it has got attachment from here this region is referred to as the superior nuclear line then this region is referred to as the legamentum nuke then spines of all 12 thoracic vertebrae okay. It has got such extensive origin then distal attachment of trapezius it has got fibers upper fibers middle fibers and lower fibers upper fibers goes to the clavicle upper fibers goes to the clavicle the lateral one-thirds of the clavicle posterior border is the attachment of upper fibers of trapezius. Middle fibers of trapezius are attached along the medial margin of the acromion as well as the upper lip of the spine of the scapulae okay and the lower fibers of trapezius they are attached on to a region along the lower lip of the spine of the scapulae that there's a small elevation is referred to as deltoid tubercle okay deltoid tubercle give attachment to the lower fibers of trapezius. Now supply of trapezius is by the spinal part of the accessory nerve then actions of trapezius and there are three types of fibers of trapezius actions are described with respect to the fibers upper fibers of the trapezius will act along with levator scapulae to elevate the scapulae middle fibers of the trapezius will act along with rhomboids to retract the scapulae lower fibers of the trapezius will act along with ceratus anterior to help in overhead abduction of the shoulder joint okay then latissimus dorsi muscle latissimus dorsi proximal attachment is from the iliac crest posterior aspect then thoracolumbar fascia posterior lamina of thoracolumbar fascia then lower six spines of the thoracic vertebrae then there's a small attachment from the inferior angle of the scapulae okay so it has got such extensive origin and it goes up to the floor of the bicepital groove okay bicepital groove also referred to as inter tubercular sulcus floor gives attachment to the latissimus dorsi muscle okay now supply of latissimus dorsi it is the nerve to latissimus dorsi also called as thoracodorsal nerve root value is c6 c7 and c8 okay c6 c7 c8 is the root value for nerve to latissimus dorsi then actions of latissimus dorsi it is remembered by remembering the swimming action in swimming we do adduction medial rotation and extension at the shoulder joint so latissimus dorsi actions are adduction medial rotation and extension of the shoulder joint okay then deep muscles levator scapulae proximal attachment of levator scapulae from the transfer process of the upper four cervical vertebrae distal attachment is along the medial border of the scapula above the root of the spine okay this this part is referred to as the root of the spine of the scapula about the root of the spine is levator scapulae opposite the root of the spine the muscle is rhombus minor and below the root of the spine the muscle is rhombus major okay so medial border you can remember attachments with respect to the root of the spine of the scapulae then now supply of levator scapulae it receives supply directly from C3 and C4 spinal nerve as well as from the nerve to rhombus nerve to rhombus is dorsal scapular nerve which is having root value C5 okay then action of levator scapulae is it will elevate the scapula rhombus minor and rhombus major proximal attachment of rhombus minor is from the finest process of C7 and T1 and for rhombus major it is T2, T3, T4 and T5 okay distal attachment I've already covered opposite the root of the spine is rhombus minor below the root of the spine is rhombus major now supplies by dorsal scapular nerve root value C5 arising from the directly from the roots of the brachial plexus C5 nerve root action of rhombus minor and major is they will help in retraction of the scapula let's cover the scapulo-humeral muscles now so as the name suggests they connect the scapula to the humerus you have six in number deltoid then these four muscles are of the rotator cuff sub scapular is supraspinitis in plus finitis and teres minor and one more muscle is teres major okay let's start with the deltoid first for deltoid muscle proximal attachment it is again remembered by three types of fibers anterior fibers middle fibers and posterior fibers and interior fibers of deltoids will arise from this are the anterior fibers of deltoids will arise from the anterior border of the lateral one-thirds of the clavicle middle fibers of the deltoid arise from the acromion process the lateral margin of acromion and posterior fibers of deltoids whereas from the lower lip of the spine of the scapula okay then distal attachment of deltoid muscle, it goes up to a region on the humerus which is referred to as deltoid tuberosity which is along the anterolateral surface of the humerus and nerve supply is axillary nerve, nerve supply is axillary nerve having root value C5 and C6, okay. Actions of deltoid, deltoid is the chief abductor of the shoulder joint especially the middle fibres of deltoid 15 to 90 degrees of abduction is done by deltoid muscle, okay. Anterior fibres of deltoid will help in flexion at the shoulder joint, posterior fibres will help in extension at the shoulder joint, then these four muscles of the rotator cuff, subscapularis is seen on the anterior aspect that is other three muscles are seen on the posterior aspect, here this is the anterior view, this muscle is subscapularis, okay arises from the subscapular posa goes laterally to get attached along the lesser tubercle of the humerus, okay. The nerve supply of subscapularis muscle is upper and the lower subscapular nerve and action of subscapularis and this muscle contracts it will help in medial rotation at the shoulder joint, okay. Then supraspinatus muscle, this muscle is supraspinatus arising from the supraspinus posa, this muscle is infraspinatus arising from the infraspinus posa and this muscle is pteris minor, okay. Pteris minor arises from the lateral border of the scapula upper two-thirds, okay. Upper two-thirds of the lateral border is pteris minor and lower one-thirds of the lateral border is pteris major. So, here we can see S-I-T, S-I-T you can remember for attachments along the greater tubercle of the humerus, okay. Greater tubercle has got three impressions, upper impression, middle impression and lower impression, upper impression will give attachment to the supraspinatus, middle impression will give attachment to the intraspinatus and the lower impression will give attachment to the pteris minor muscle. Pteris major muscle it goes along the anterior aspect to get attached along the medial lip of the bicepital groove, okay. Lateral lip was pectoralis major, medial lip is pteris major and floor is latissimus dorsi for bicepital groove. So, attachments have covered actions, actions of supraspinatus it helps in initiation of abduction, 0 to 15 degrees of abduction is done by supraspinatus muscle, okay. Actions for intraspinatus and pteris minor are they will help in lateral rotation at the shoulder joint and for pteris major since it is going on the anterior aspect when it contracts it will help in medial rotation of the shoulder joint. Now, let's cover the muscles of the arm. So, muscles of the arm, there are five muscles, three muscles in the anterior compartment, two muscles in the posterior compartment. Let's start with the biceps, break high first. As the name suggests, biceps it means it has two heads of origin. One head, this is the short head of the biceps which arises from the tip of the corocod process along with coricobrachialis muscle. Long head of the biceps arises from the supragleno tubercle. It has got an intra-capsular origin. Then, distal attachment of biceps, break high. The tendon gets attached along the radial tuberosity rough posterior aspect and there is one more distal attachment that is the bicepital eponeurosis. Bicepital eponeurosis will fuse with the deep tissue of the forearm. Now, supply of all these three muscles is muscular cutaneous nerve, root value is C5, C6 and C7 from the lateral cord of the brachial plexus. Actions, biceps, break high will cause flexion at the elbow joint as well as it is a strong supineator in flexed elbow. Then, coricobrachialis proximal attachment we have covered that is the tip of the corocod process. Distal attachment is it goes up to the medial border of the humerus, middle 5 cm. Now, supply is again muscular cutaneous nerve. Action is adduction at the shoulder joint. Brachialis muscle proximal attachment is from the anterior aspect of the humerus, the lower half entirely the anterior medial surface, anterior lateral surface, anterior border entirely is covered by brachialis muscle. Distal attachment it goes up to the anterior aspect of the coronavirus of the ulna, the region is referred to as ulnar tuberosity. Now, supply is muscular cutaneous nerve, action will be flexion at the elbow joint. Then, muscles of the posterior compartment, triceps break high is the cheek muscle of the posterior compartment, triceps as the name suggests it will have three heads of origin. Long head of the triceps arises from the intraglinoid tubercle. Here we can see this is the intraglinoid tubercle this is the long head of triceps. This is the lateral head of the triceps and here is the medial head of the triceps. Three heads of origin distill attachment it goes up to the olecranon process of the ulna. Nerve supply is radial nerve having root value of the entire brachial plexus, C5, C6, C7, C8 and T1. Then, action is extension at the elbow joint. Articularis cubitii muscle it is considered as a detached part of the triceps break high muscle. It is present deep to the medial head of the triceps. It helps in pulling the capsule of the elbow joint. Let us start with the muscles of the forearm. So, in this slide we will cover the muscles of the anterior compartment of the forearm. In anterior compartment there are five superficial muscles and three deep muscles. Five superficial muscles are pronated teris, plexar carpi radialis, pamaris longus, plexar carpi ulnaris and plexar digitorum superficialis. All these muscles will have proximal attachment from the medial epicondyle of the humerus. That is also referred to as common plexar origin. So, proximal attachment is easy for all the muscles. Some muscles have additional heads of origin. For example, pronated teris has got two heads of origin. Plexar carpi ulnaris has got two heads of origin. Plexar digitorum superficialis has got two heads of origin. Distal attachment of pronated teris is, it is along the lateral surface of the radius. Then nerve supply, if we see, all muscles are supplied by median nerve, except plexar carpi ulnaris. Plexar carpi ulnaris is supplied by ulnar nerve. That is all muscles are supplied by median nerve. Action of pronated teris will be pronation of the forearm. Then plexar carpi radialis, distal attachment, it goes up to the base of the second and the third metacarpal. Parmar aspect of the base of the second and the third metacarpal is distal attachment for plexar carpi radialis. Now, supply is median nerve. Action is plexion at the wrist joint as well as it will cause abduction at the wrist joint acting along with extensor carpi radialis longest and bravest. Then, parmar is longest. Distal attachment, it goes up to the plexar retinagulum and it continues up in the hand as the parmar aponeurosis. It is a weak flexor at the wrist joint. Plexar carpi ulnaris, distal attachment, it goes up to the pisiform bone and from pisiform bone, there are two ligaments, pisohamide and pisometacarpal ligaments through which it goes up to the base of the fifth metacarpal. Parmar aspect of the base of the fifth metacarpal is plexar carpi ulnaris. Then, plexar digitorum superficialis, distal attachment, it goes up to the middle phalanx. It splits at the level of proximal phalanx and it gets attached along the sides of the middle phalanx. Action of plexar digitorum superficialis will be plexion of the proximal inter phalanxial joint as well as plexion at the proximal joint which it crosses. Action of plexar carpi ulnaris was left. Plexar carpi ulnaris will cause plexion at the wrist joint as well as it will cause adduction at the wrist joint acting along with extensor carpi ulnaris. Now, let us cover the deep muscles. There are three numbers, plexar digitorum profundus, plexar polises longus and pronator quadratus. Proximal attachment of plexar digitorum profundus, it arises from the anterior aspect as well as the medial aspect of the ulnaris. Distal attachment, it goes up to the distal phalanx. Palmer aspect of the base of the distal phalanx. Now, supplier plexar digitorum profundus, it is a hybrid muscle. Medial half is supplied by ulnar nerve, lateral half is supplied by anterior interosseous nerve which is the branch of the median nerve. Then, action of plexar digitorum profundus, it is an explosive plexar of the distal inter phalanx joint as well as it will flex the proximal joints which it crosses. In plexar polises longus, it arises from the anterior aspect of the radius below the anterior oblique line and distal attachment, it goes up to the distal phalanx of the thumb. Action will be flexion of the thumb. Nerve supply of all these three muscles is anterior interosseous nerve except plexar digitorum profundus which is a hybrid muscle. Medial half is supplied by ulnar nerve, lateral half is supplied by anterior interosseous nerve. Pronator quadratus, proximal attachment is from the ulnar, the lower one-fourth anterior aspect and distal attachment is on the radius. Now, supply anterior interosseous nerve, action will be pronation of the forearm. Now, let us cover the muscles of the posterior compartment of the forearm. The posterior compartment of the forearm, the list is a bit extensive. There are seven superficial muscles and five deep muscles. So, how easily we can remember these seven superficial muscles? We can group them into groups of three. These three muscles we can remember together, brachioradialis, extensor carpi radialis longus and extensor carpi radialis brevis and these three muscles together, extensor digitorum, extensor digiti minimi and extensor carpi ulnaris and in deep muscles also we can remember these three muscles together. Abductor polis is longus, extensor polis is longus and extensor polis is brevis. These three muscles are referred to as muscles of the anatomical snuff box. These are also referred to as outcropping muscles. So, if we group them into groups of three, only three more muscles are left. That is how there are 12 muscles in the posterior compartment of the forearm. Let us start with the anconious. Anconious proximal attachment is from the lateral epicondyle of the humerus, posterior aspect. Dissil attachment is along the upper one-fourth of the ulnar. Now, supply is radial knuff and action is it is a weak extensor of the elbow joint. Now, supply if we see these first three muscles are supplied directly by the radial knuff and the remaining muscles are supplied by posterior introsius knuff. Even the deep muscles, all five deep muscles are supplied by posterior introsius knuff. So, only anconious, brachioradialis and extensor corpi radial is along the, these are supplied by, these are supplied directly by the radial knuff. Rest all are supplied by posterior introsius knuff which is the branch of the radial knuff. Then brachioradialis, proximal attachment is from the lateral suprapondylar ridge. The upper part of lateral suprapondylar ridge. Dissil attachment it goes up to the styloid process of the radius. The styloid process of the radius is dissil attachment for brachioradialis. Action of brachioradialis is it will cause flexion at the elbow joint and it can cause pronation and supination as well. In completely pronated forearm, it can bring to mid-prone position. Similarly, in completely supine, supinated forearm it can bring the forearm to mid-prone position. The next extensor corpi radial is longus. This muscle also rises from the lateral suprapondylar ridge, the lower one-third. Then extensor corpi radial is bravis. It arises from the lateral epicondyle of the humerus, the common extensor origin. And these muscles are attached, distill attachment of these muscles are along the dorsal aspect of the base of the second and the third metacarpals. Okay. Amar aspect of the base of second and third metacarpals was flexor corpi radialis. Dorsal aspect of the base of the second and the third metacarpals is extensor corpi radialis longus and bravis. Then extensor digitorum muscle, proxenal attachment is from the lateral epicondyle of the humerus. Distal attachment, it will go up to the middle phthalings as well as the distal phthalings. Okay. Extendant will be splitting into three components like this. The middle component will attach onto the middle phthalings. These two components will unite to get attached onto the distal phthalings. Action will be extension of the digits as well as extension at the resjoint. Extensor digiti minimi, proxenal attachment from the lateral epicondyle of the humerus. Distal attachment, it goes up to the distal phthalings of the little finger. Okay. Digiti minimi stands for the little finger. Extensor corpi ulnaris, proxenal attachment again from the lateral epicondyle of the humerus. Distal attachment, it goes up to the base of the fifth metacarpal. Okay. Dorsal aspect of base of fifth metacarpal is extensor corpi ulnaris. Action of extensor corpi ulnaris will be extension at the resjoint and acting along with flexor corpi ulnaris, it will cause adduction at the resjoint. Okay. Similarly, for extensor corpi radialis longus and bravis, it will cause extension at the resjoint as well as acting along with flexor corpi radialis, it will cause abduction at the resjoint. Okay. Now, let's cover the five deep muscles. Supionator muscle, it is more clearly seen in the floor of the cubital posa. This muscle, which you can see, this is supionator muscle arising from the lateral epicondyle of the humerus as well as from the supionator crest. Distal attachment is on the lateral surface of the radius, above the attachment of pronator terris muscle. The nerve supply is posterior interosseous nerve and actions of supionator is, it will cause supination of the forearm. Okay. And these three muscles are of the anatomical snuff box. Abductor posa is longus. It has attachment from the radius as well and from the ulna as well. Okay. This muscle is abductor posa is longus. This muscle is extensor posa is bravis. And this muscle is extensor posa is longus. Okay. In this series, we can remember the distal attachment. Extensor posa is longus, goes up to the distal paling. Extensor posa is bravis, goes up to the proximal paling. And abductor posa is longus, will go up to the base of the first metacarpal. Okay. That's how in series, we can remember the distal attachment of these three muscles. Now supplies by posterior interosseous nerve for all. Action with respect to the name we can remember. Abductor posa is longus, will cause abduction. Extensor posa is longus and bravis will cause extension of the thumb. Okay. Then extensor indices, indices refers to the index finger. Proximal attachment of extensor indices is from the ulna. Distal attachment, it goes up to the torso aspect of the distal paling of the index finger. Okay. Action will be it will cause extension of the index finger as well as it will be a weak extensor at the base joint. Now let's cover the muscles of the hand. These are twenty in number. You can group them into groups of four, four thenar muscles, four hypothenar muscles, four lumbaricals, four palmarintrosiae and four dorsal introsiae. Okay. Here we can see this is the location of the thenar muscle. This muscle is abductor polis is bravis. This muscle is flexor polis is bravis. And we retract these two muscles. The muscle in the deeper plane will be opponent's polisis. And this muscle is adductor polisis. Okay. These are the four thenar muscles. Thenar muscles are four, but these three muscles are included in thenar eminence. Adductor polisis is not included in thenar eminence. Okay. Then hypothenar muscles are seen along the medial side. This muscle is abductor digitiminimine. This muscle is flexor digitiminimine. This muscle is opponent's digitiminimine. There is one more muscle just beneath the skin that is palmaris bravis muscle. Okay. These are the hypothenar muscles. Then lumbaricals, they are four in number. Their attachment is along the tendons of the flexor digitorum propandus muscle, proximal attachment. Distal attachment of lumbaricals is it goes up to the dorsal digital expansion. Okay. In lumbaricals, the lateral two lumbaricals are unit in it and the medial two lumbaricals are biped in it. In palmarintrosia and dorsal introsiae, as the word suggests introsiae, that means it is present in between the metacarpals. In between the bones, the muscle is named as introsiae. So there are four palmarintrosiae and four dorsal introsiae. In palmarintrosiae, there will be no palmarintrosiae attached along the middle finger. Okay. Or the middle metacarpal. Actions of these three muscles are important. Actions of lumbaricals, palmarintrosiae and dorsal introsiae are such that it will cause flexion of the metacarpal pharyngeal joint and extension at the interpharyngeal joint. And then these muscles are affected in clump case paralysis. The clinical condition is referred to as claw hand. In claw hand what occurs? There is hyperextension at the metacarpal pharyngeal joint and flexion at the interpharyngeal joint. Okay. In nerve supply of these muscles of the hand, we should remember 16 and a half and 4 and a half formula. Okay. 16 and a half muscles are supplied by ulnar nerve and 4 and a half muscles are supplied by median nerve. Okay. So if you remember this 4 and a half, remember all muscles we can add on for the ulnar nerve. So what is this 4 and a half? Two are the lumbaricals. The first lumbarical and the second lumbarical. Okay. Two lumbaricals. Abductor policies bravis. Half of flexor policies bravis. Half is included here and half is included here. Okay. Flexor policies bravis is a hybrid muscle. One half is supplied by median nerve, other half is supplied by ulnar nerve. Opponents policies is one more muscle. So opponents policies, abductor policies bravis, these two, these two and half of flexor policies bravis. These 4 and a half muscles are supplied by median nerve, rest all muscles are supplied by ulnar nerve. Okay. So we have covered all the muscles of the upper limb. In general if you want to remember the number of the muscles, up to elbow there are 20 muscles in upper limb, elbow to wrist there are 20 muscles and beyond wrist there are 20 muscles. Okay. So in all there are 60 muscles. The exact distribution of this muscles you can find in one of the video, this channel. Okay. So this was all about this particular session. If you have any doubts then you all can ask in the comment section below. Okay. Thank you.