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2. Suture – the joint between the bones of the skull. 3 forms: a.Serrate a. Serrate suture (a see-saw form); b.Squamous b.Squamous suture c.Plane c. Plane suture 3. Syndesmosis – these are the strongest joints, as there is almost no movement in these joints.
UPPER LIMB Types of bones: bones: 1. Long bones (e.g. humerus, ulna, radius) – the length is bigger than the width; 2. Short bones (e.g. carpal bones of the wrist) – difference between the length and width is not significant; 3. Flat bones (e.g. sternum); 4. Irregular bones (e.g. vertebrae, facial bones) – these have no specific shape; Histologically, bones can be either spongy or compact: 1. Spongy bones: contain many cavities filled with red marrow (they function in hemopoiesis); 2. Compact bones: the connective tissue is highly dense. Normally, the outer shell of all bones is made of a compact bone. Long bones have several parts that should be mentioned: 1. Epiphysis – the part of the bone that articulates with another bone; the epiphysis is covered by articular cartilage. 2. Diaphysis – the shaft of the bone – the longest part containing the bone marrow cavity. 3. Metaphysis – the part between the epiphysis and diaphysis, which contains the epiphyseal plate; because of their rich blood supply, they are prone to spread of osteomyelitis in children. 4. Epiphyseal plate (growth plate) – responsible for growth in the length of the bone; 5. Periosteum – a layer of dense connective tissue covering the outer part of the bone (except at the joint); 6. Endosteum – a layer of dense connective tissue covering the bone from the inner side. Joints By large, there are 3 types of joints: fibrous joints, cartilaginous joints and synovial joints:
Cartilaginous joints (when cartilage connects 2 bones). 2 subtypes: 1. Synchondrosis – when the connecting medium is cartilage (can be temporary or permanent). Example for permanent synchondrosis: the sternocostal joint; example for temporary synchondrosis: epiphyseal plate, the sphenopetrosal joint and the petrosquamous joint (these are in the skull – don't mind it now). 2. Symphysis – a fibrocartilaginous fusion between 2 bones that is Example: pubis permanent . symphysis (the joint connecting the anterior aspect of the hip bones). Synovial joint diarthroses) are the Synovial joints (or diarthroses) most common and most movable type of joints in the human body. Structural and functional differences distinguish synovial joints from cartilaginous joints and fibrous joints. The main structural differences between synovial and fibrous joints is the existence of a capsule surrounding the articulating surfaces of a synovial joint and the presence of lubricating synovial fluid within that capsule (synovial cavity). Obligatory components of synovial joints The following must be present in order to define a joint as "synovial": 1. An articular head and socket: socket: these are the very components of the joint that form the articulation. These components are covered by articular cartilage. 2. An articular cartilage : lines the epiphyses of joint end of bone. Provides the loading and unloading mechanism to resist load and shock (as cartilage is softer than bones). The histology section covers the topic of Cartilage; nonetheless, few words should be mentioned: there can be 3
Fibrous joints: joints: 1. Gomphosis – the joint between the teeth and the jaw.
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types of cartilage: Hyaline cartilage (in most synovial joints) is a rather hard, translucent material rich in collagen and proteoglycan. It covers the end of bone(s) to form the smooth articular surface of joints. It is also found in the nose, the larynx and between the ribs and the sternum. Bones grow via a hyaline cartilage intermediate, a process called Endochondral ossification. Elastic cartilage Elastic cartilage contains large amounts of elastic fibers (elastin) scattered throughout the matrix. It is stiff yet elastic, and is important to prevent tubular structures from collapsing. Elastic cartilage is found in the pinna of the ear, in tubular structures such as the auditory (Eustachian) tubes and in the epiglottis. This type of cartilage has nothing to do with synovial joints, but is given here for the sake of "the full picture" on cartilage types. The last type is the fibrocartilage is characterized by a dense network of type I collagen. It is a white, very tough material that provides high tensile strength and support. It contains more collagen and less proteoglycan than hyaline cartilage. Thus, its properties are closer to those of tendons than hyaline cartilage. It is present in areas most subject to frequent stress like intervertebral discs, the symphysis pubis and the attachments of certain tendons and ligaments. Fibrocartilage, in addition to its function as weight bearing material, also functions in the adaptation of articulating surfaces. In the knee, for instance, the meniscus (fibrocartilage) matches the femur condyles with the tibia almost-plain surface. In the upper limb such fibrocartilage is found in the acromioclavicular joint, the sternoclavicular joint and in the radiocarpal joints (see explanations ahead). 3. Articular capsule : The fibrous capsule (dense connective tissue) is continuous with the periosteum of bone. It weakly encloses the articulating bones. Hence, ligaments
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come to the rescue of the joint stability. It is also highly highly innervated but avascular (lacking blood and lymph vessels) 4. Synovial membrane: membrane: the inner layer of the fibrous articular capsule. The synovial membrane covers the lining of the synovial cavity where articular cartilage is absent. The highlyvascularized epithelium secretes the synovial fluid. 5. Synovial fluid : this serous fluid lubricates the articular cartilage the cushions the joint during movements. Clinical Correlate Cracking Joints: When two parts forming a joint are pulled away from each other, the joint capsule increases in volume but the synovial fluid in the capsule no longer fills it all. Gases dissolved in the fluid quickly fill the empty space causing a sharp cracking sound. The general term for this is cavitation. In each joint it takes different time for the fluid to be resecreted and reabsorbed. Thus, in the interphalangeal joints (the joints of the fingers) one cannot crack them for some 30 minutes after the initial crack, while in the cervical intervertebral joint it can be done minutes apart. What's wrong in cracking the joint? As the joint is cracked, the 2 articulating bones are pressed against one another increasing the stability of the joint, which reduces pain if present. Chiropractors use this technique quite often. However, as the friction between the 2 bones increases with no synovial fluid, the joint becomes more eroded, and various pathologies develop. The patient keeps returning to the chiropractor in decreasing intervals to alleviate the pain while further increasing the erosion of the joint. Physiotherapists are justifiably against this technique, but seldom practice it if the joint is already eroded, or if the consequences of the pain are greater than those of the unwelcome erosion. If you persistently crack your spinal column (or any other joint) – stop it! Accessory components of synovial joints 1. Ligaments: Ligaments: dense connective tissue that connects the articulating bones
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and hold them in place. The ligaments are those structures that prevent excess movement of the joint. Ligaments are of 3 types: a. Intracapsular: Intracapsular: located within the capsule (e.g. the cruciate ligament in the knee) b.Capsular b.Capsular:: located on the capsule (and are thus often regarded as "thickening" of the capsule) c. Extracapsular: Extracapsular: located outside the capsule (e.g. the collateral ligaments). 2. Bursae (from Latin: a sac): a small fluid-filled sac made of white fibrous tissue and lined with synovial membrane (that secretes the synovial fluid). It provides a cushion between bones and tendons and/or muscles around a joint; bursae are filled with synovial fluid and are found around almost every major joint of the body; when they become inflamed, the bursitis. Usually condition is called bursitis. occurring in locations subject to friction, bursae enable one structure to move more freely over another. Subcutaneous bursae occur in the subcutaneous tissue between skin and bony prominences, such as the elbow or knee; subfascial bursae lie beneath deep fascia; and subtendinous bursae facilitate the movement of tendons over bone.
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3. Plane (gliding) joint (e.g. intercarpal joints): a synovial joint which admits of only gliding movement. The gliding joint allows one bone to slide over the other. The gliding joint in your wrist allows to flex your wrist. It also makes very small side motions. There are also gliding joints in your ankles. Biaxial joints (2º): these joints can move around 2 axes: 1. Condylar joints (e.g. metacarpophalageal joint): an ovoid articular surface, or condyle, is received into an elliptical cavity in such a manner as to permit flexion, extension, adduction, abduction, and circumduction, but no axial rotation. 2. Saddle joint (e.g. sternoclavicular joint, carpometacarpal joint): the movements in these joints are the same as in condylar joint (however, morphologically they look like a saddle). Triaxial joints (3º): these joints are the most mobile and can move around 3 axes: 1. Ball and Socket (e.g. the shoulder joint and the hip joint).
Bones of the Upper Limb Scapula (the followings should be identified): Superior angle; Superior margin; Superior notch; Neck; Medial angle; Medial margin; Subscapular fossa; Infraglenoid tubercle; Lateral margin; Inferior angle; Coracoid process; Glenoid cavity; Supraspinous fossa; Spine of scapula; Infraspinous fossa; Groove for circumflex scapular vessels; acromion; supraglenoid tubercle. nd th Surface projection: 2 -7 ribs Positioning: Positioning: position the spine posteriorly, the glenoid cavity laterally and the inferior angle inferiorly. WARNING: inability to position the bones correctly and determine whether it is the left-side bone or the right-side one will result in immediate failure! Clavicle: Clavicle: Acromial extremity; sternal extremity; trapezoid line; conoid tubercle; groove for
Classification of Joints Joints are classified according to their shape (hinge, pivot, plane, condylar, saddle and bone & socket) and according to their degree of freedom (1º, 2º, 3º) Uniaxial joints (1º): these joints move around a single axis: 1. Hinge joint (ginglymus) (e.g. interphalangeal joint can only flex and extend in the sagittal plane); the direction which the distal bone takes in this motion is seldom in the same direction as that of the axis of the proximal bone; there is usually a certain amount of deviation from the straight line during flextion (around 11º in the elbow for example). 2. Pivot joint (e.g. the proximal radioulnar joint): this is where one bone rotates about the other.
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subclavius muscle; impression for costoclavicular ligament (costal tubercle). Positioning: Positioning: position the rounded, bulky end medially; position the arch near this end anteriorly and the smooth side superiorly. Functions: to allow the limb maximal freedom of motion by keeping it away from the trunk; forms the cervicoaxillary canal (protection of the neurovascular bundle); transmits shock from the limb to the axial skeleton. Weakest point – the junction between the middle and lateral thirds. Humerus: Humerus: Head of humerus; anatomical neck; surgical neck; greater tubercle; lesser tubercle; intertubercular groove (bicipital groove); deltoid tubersity; medial and lateral condyles; medial and lateral epicondyles; capitulum; radial fossa; coronoid fossa; trochlear; groove for radial nerve; groove for ulnar nerve; olecranon fossa. Positioning: Positioning: position the head superiorly and medially. Position the olecranon fossa posteriorly. Common site of fracture: surgical neck. The following parts of the humerus are in direct contact with the indicated nerves: Surgical neck: axillary nerve; Radial groove: radial nerve; Distal end of humerus: median nerve; Medial epicondyle: ulnar nerve These nerves may be injured when the associated parts are fractured. Radius Head; neck; radial tuberosity; anterior and posterior margins; anterior and posterior surfaces; interosseous margin; styloid process; groove for extensor pollicis
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longus muscle; groove for extensor digitorum and extensor indicis muscles; groove for extensor carpi radialis longus and brevis muscles; area for extensor pollicis brevis and abductor pollicis longus muscles; articulating surfaces for scaphoid bone and lunate bone; ulnar notch of radius. Positioning: Positioning: position the head proximally, the styloid process inferiorly and laterally. Position the radial tuberosity anterolaterally. Clinical correlate A complete transverse fracture of the distal 2 cm of the radius is called Colles fracture, and it is the most common fracture of the forearm in adults over 50 years of age Ulna Olecranon; trochlear notch; coronoid process; radial notch of ulna; tuberosity of ulna; anterior and posterior surfaces and margins; interosseous margin; styloid process. Positioning: Positioning: position the trochlear noth proximally and facing forward. The styloid process should face medially. Wrist The 8 carpal bones should be positioned in 2 rows. First row (1º): Scaphooid; lunate; triquetrum; pisiform; Second row (2º): trapezium; trapezoid; capitate; hamate. Mnemonics: 1º: Scared Scared Lovers Try Positions 2º: That That They Can't Handle Metacarpal bones: Head; body; base (proximal) Phalanges: Head; body and base
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Name and type
Articulating surfaces
Capsule
Accessories
Movements
Shoulder joint – ball and socket
Head of humerus – head; glenoid cavity and glenoid labrum – socket. The articular cartilage and the glenoid labrum are made of hyaline cartilage
Loose capsule. Originates around the bony rim of the glenoid cavity and inserts around the anatomical neck of the humerus. At the bicipital groove it gives a downward extension which houses the tendon of the long head of the biceps
There are no disks. Ligaments: glenohumeral lig. (capsular); coracoacromial lig. Coracohumeral lig. Transverse humeral lig. (extracapsular) Bursae (~12): subacromial bursa and subscapular bursa
Flexionextension; abductionadducion; medial and lateral rotation; circumduction
The articular disc compensate the incongruity of the articulating surfaces, and functions mainly as shock absorber. It separates the joint into 2 compartments. Made of fibrocartilage. Ligaments: anterior and posterior sternoclavicular ligaments (attach to the disc); interclavicular ligament; costoclavicular lig. No bursae The acromial end of Relatively loose. It is There is an articular disc the clavicle joins attached to the margins of (fibrocartilage) dividing the
Elevationdepression (~60º in the sagittal plane); anteriorposterior mvmt (~25º ); rotation along the long axis.
Internal thoracic artery and suprascapular artery. The supraclavicular nerve and the subclavius nerve.
Gliding sliding
Suprascapular artery and
Sternoclavicular The sternal end joint – saddle joint the clavicle that functions as ball attached to and socket joint clavicular notch the manubrium fibrocartilage
Acromioclavicular joint – plane joint
of is the of via
Tight capsule that inserts around the epiphysis of the clavicle and the clavicular notch of the sternum.
and
Blood and nerve supply Circumflex humeral arteries and subscapular artery. Suprascapular nerve, axillary n. and lateral pectoral n.
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with the acromion of the articular surfaces. the scapula. Both surfaces are lined with fibrocartilage.
Elbow joint (hingepivot): 3 joints included: Humeroulnar jt. (HUJ) ; humeroradial jt (HRJ). ; radioulnar jt.(PRUJ)
The trochlear of the humerus articulates with the trochlear notch of the ulna (hinge); the capitulum of the humerus articulates with the head of the radius (ball & socket); the radius articulates with the radial notch of the ulna (the proximal radioulnat joint – pivot). All surfaces are lined with hyaline cartilage.
Tight capsule in the sides, very loose posteriorly and moderately loose anteriorly. In the humerus, the capsule encloses the coronoid and the olecranon.
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joint (incompletely). Ligaments: the acromioclavicular lig. (capsular); the coracoclavicular lig and the trapezoid lig are the most important stabilizers (extracapsular). No bursae. Ligaments: radial and ulnar collateral ligaments limiting the medio-lateral movements; the annular ligament (intracapsular) binds the head of the radius to the radial notch of the ulna creating the pivot joint. No discs. Bursae: the 3 olecranon bursae are intratendinous, the subtendinous bursa and the subcutaneous olecranon bursa. The intratendinous bursa occasionally exists in the tendon of the triceps brachii. The subtendinous bursa lies just proximal to the attachment of the triceps tendon, separating the tendon from the olecranon. olecranon. The subcutaneous olecranon bursa
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thoracoacromial artery. Supraclavicular nerve; lateral perctoral nerve; axillary nerve.
HUJ: flexionextension; HRJ: flexionextension and rotation; PRUJ: rotaion
Rete cubiti n. musculocutaneous n. radial n. and ulnar n. Blood: the brachial artery descends through the anterior compartment of the elbow. Before it reaches the elbow, the brachial artery gives off branches that help form a plexus of vessels around the elbow. The superior and inferior ulnar collateral arteries, the deep brachial artery, and the
Other Capsule and ligaments are very loose to allow high degree of movements. Stability is thus compromised. The rotator cuff muscle provide dynamic stability: supraspinatus mm. infraspinatus mm. subscapularis mm. and teres minor mm.
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with the acromion of the articular surfaces. the scapula. Both surfaces are lined with fibrocartilage.
Elbow joint (hingepivot): 3 joints included: Humeroulnar jt. (HUJ) ; humeroradial jt (HRJ). ; radioulnar jt.(PRUJ)
The trochlear of the humerus articulates with the trochlear notch of the ulna (hinge); the capitulum of the humerus articulates with the head of the radius (ball & socket); the radius articulates with the radial notch of the ulna (the proximal radioulnat joint – pivot). All surfaces are lined with hyaline cartilage.
Tight capsule in the sides, very loose posteriorly and moderately loose anteriorly. In the humerus, the capsule encloses the coronoid and the olecranon.
joint (incompletely). Ligaments: the acromioclavicular lig. (capsular); the coracoclavicular lig and the trapezoid lig are the most important stabilizers (extracapsular). No bursae. Ligaments: radial and ulnar collateral ligaments limiting the medio-lateral movements; the annular ligament (intracapsular) binds the head of the radius to the radial notch of the ulna creating the pivot joint. No discs.
thoracoacromial artery. Supraclavicular nerve; lateral perctoral nerve; axillary nerve.
HUJ: flexionextension; HRJ: flexionextension and rotation; PRUJ: rotaion
Bursae: the 3 olecranon bursae are intratendinous, the subtendinous bursa and the subcutaneous olecranon bursa. The intratendinous bursa occasionally exists in the tendon of the triceps brachii. The subtendinous bursa lies just proximal to the attachment of the triceps tendon, separating the tendon from the olecranon. olecranon. The subcutaneous olecranon bursa
Rete cubiti n. musculocutaneous n. radial n. and ulnar n. Blood: the brachial artery descends through the anterior compartment of the elbow. Before it reaches the elbow, the brachial artery gives off branches that help form a plexus of vessels around the elbow. The superior and inferior ulnar collateral arteries, the deep brachial artery, and the
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lies within the subcutaneous tissues over the olecranon.
Distal radioulnar jt. – pivot.
The head of the ulna articulates with the ulnar notch of the radius. the triangular articular disc binds the styloid process of the ulna with the ulnar notch of the radius. All structures are lined with hyaline cartilage. Wrist joint – The carpal condyloid articulating surface of the radius and the articular disc articulate with the scaphoid, lunate and triquetrium. All surfaces are lined with hyaline cartilage. Intercarpal joints – All wrist bones plane joints articulate with one another. All surfaces are lined with hyaline cartilage Carpometacarpal The distal row of the joint (CMJ) – plane carpal bones and the
radial collateral artery supply the elbow from above. Anterior and posterior interosseus arteries and nerves.
L-shaped capsule. It has a proximal extension called sacciform recess. Moderately loose.
Dorsal and palmar carpal ligaments. No bursae. Disc: the triangular articular disc binds the styloid process of the ulna with the ulnar notch of the radius.
Pronation and supination (the PRUJ is also involved in pronationsupination).
Originates from and inserts onto the rim of the articulating bones. Moderately tight at the sides, but looser anteriorly and posteriorly.
Palmar and dorsal carpal ligaments; ulnar and radial collateral ligaments; NO bursae. Disc: the articular disc articulate with the scaphoid, lunate and triquetrium.
Dorsiflexion (= extension) and palmar flextion; abductionadduction
Dorsal and palmar carpal arteries; Branches of the median n. ulnar n. and radial n.
Common capsule for the intercarpal joint and the carpometacarpal joints (II-V). moderately tight.
Dorsal, palmar and collateral radiocarpal ligaments.
Gliding sliding
Tight capsule. originates from
The palmar carpometacarpal lig. and the palmar metacarpal
Gliding and st sliding. 1 CMJ
Dorsal and palmar carpal arteries; Branches of the median n. and ulnar n. Dorsal and deep palmar arches
It and
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lies within the subcutaneous tissues over the olecranon.
Distal radioulnar jt. – pivot.
The head of the ulna articulates with the ulnar notch of the radius. the triangular articular disc binds the styloid process of the ulna with the ulnar notch of the radius. All structures are lined with hyaline cartilage. Wrist joint – The carpal condyloid articulating surface of the radius and the articular disc articulate with the scaphoid, lunate and triquetrium. All surfaces are lined with hyaline cartilage. Intercarpal joints – All wrist bones plane joints articulate with one another. All surfaces are lined with hyaline cartilage Carpometacarpal The distal row of the joint (CMJ) – plane carpal bones and the
radial collateral artery supply the elbow from above. Anterior and posterior interosseus arteries and nerves.
L-shaped capsule. It has a proximal extension called sacciform recess. Moderately loose.
Dorsal and palmar carpal ligaments. No bursae. Disc: the triangular articular disc binds the styloid process of the ulna with the ulnar notch of the radius.
Pronation and supination (the PRUJ is also involved in pronationsupination).
Originates from and inserts onto the rim of the articulating bones. Moderately tight at the sides, but looser anteriorly and posteriorly.
Palmar and dorsal carpal ligaments; ulnar and radial collateral ligaments; NO bursae. Disc: the articular disc articulate with the scaphoid, lunate and triquetrium.
Dorsiflexion (= extension) and palmar flextion; abductionadduction
Dorsal and palmar carpal arteries; Branches of the median n. ulnar n. and radial n.
Common capsule for the intercarpal joint and the carpometacarpal joints (II-V). moderately tight.
Dorsal, palmar and collateral radiocarpal ligaments.
Gliding sliding
Tight capsule. originates from
The palmar carpometacarpal lig. and the palmar metacarpal
Gliding and st sliding. 1 CMJ
Dorsal and palmar carpal arteries; Branches of the median n. and ulnar n. Dorsal and deep palmar arches
It and
and
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and intermetacarpal joints – plane st The 1 CMJ (thumb) is saddle joint Metacarpophalangeal (MPJ) – condylar; and interphalangeal joints (IPJ) – hinge
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bases of the metacarpals. The bases of the metacarpals articulate with one another (digits II-V) The MPJ are between the head of the metacarpals and the bases of the proximal phalanges. The IPJ are between the heads of the phalanges and the bases of the phalanges in the next row. All surfaces are lined with hyaline cartilage.
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inserts into the edges of lig. the dorsal carpal lig. and the articulating surfaces. the dorsal interosseus lig.
– abd-add, flxext, opposition reposition. Corcumduction.
(blood supply); the radial, median and ulnar nerves.
Tight at the side, but is loose posteriorly.
MPJ: Flx-ext; abd-add; IPJ: flx-ext
The proper digital arteries and nerves supply these joints.
Collateral ligaments
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and intermetacarpal joints – plane st The 1 CMJ (thumb) is saddle joint Metacarpophalangeal (MPJ) – condylar; and interphalangeal joints (IPJ) – hinge
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bases of the metacarpals. The bases of the metacarpals articulate with one another (digits II-V) The MPJ are between the head of the metacarpals and the bases of the proximal phalanges. The IPJ are between the heads of the phalanges and the bases of the phalanges in the next row. All surfaces are lined with hyaline cartilage.
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inserts into the edges of lig. the dorsal carpal lig. and the articulating surfaces. the dorsal interosseus lig.
– abd-add, flxext, opposition reposition. Corcumduction.
(blood supply); the radial, median and ulnar nerves.
Tight at the side, but is loose posteriorly.
MPJ: Flx-ext; abd-add; IPJ: flx-ext
The proper digital arteries and nerves supply these joints.
Collateral ligaments
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Axillary Fossa (armpit) Borders: 1. Apex (triangle) a.Anteriorly: a. Anteriorly: clavicle b.Posteriorly: b.Posteriorly: scapula c.Medially: c. Medially: first rib 2. Anterior wall – anterior axillary fold: pectoralis major and minor muscles; 3. Posterior wall: a.Posterior axillary fold: latissimus dorsi mm. and teres major mm. b. Teres minor and subscapularis mm. 4. Medial wall: a.Ribs 1-4 b. Intercostal mm (1-3) c.Upper part of serratus anterior mm. 5. Lateral wall: a. Upper 1/3 of humerus b. Intertubercular (bicipital) groove c. Coracobrachialis mm d. Triceps brachii mm. 6. Base: a.The axillary fascia forms the base. Anteriorly, the anterior axillary fold limits it, and posteriorly, the
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Cutaneous Innervation of the Upper Limb 8 sensory nerves supply the skin of the upper limb: 1. Supraclavicular nerve – the only one that emerges from the cervical plexus. It can be located at the lowermost border of the sternocleidomastoid muscle as it fans over the clavicle; 2. Posterior brachial cutaneous nerve – a branch of the radial nerve that emerges posteriorly between the teres major muscle and the long head of the triceps brachii muscle. It runs along the long head of the triceps brachii; 3. Posterior antebrachii cutaneous nerve – emerges from the radial nerve but runs deep to the lateral head of the triceps brachii. It emerges out of the inferior border of the lateral head of the triceps brachii and superficially crosses the anconeus muscle and the extensor digitorum muscle; 4. Superior lateral brachii cutaneous nerve – emerges out of the axillary nerve at the level of the deltoid muscle; 5. Inferior lateral brachii cutaneous nerve
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Axillary Fossa (armpit) Borders: 1. Apex (triangle) a.Anteriorly: a. Anteriorly: clavicle b.Posteriorly: b.Posteriorly: scapula c.Medially: c. Medially: first rib 2. Anterior wall – anterior axillary fold: pectoralis major and minor muscles; 3. Posterior wall: a.Posterior axillary fold: latissimus dorsi mm. and teres major mm. b. Teres minor and subscapularis mm. 4. Medial wall: a.Ribs 1-4 b. Intercostal mm (1-3) c.Upper part of serratus anterior mm. 5. Lateral wall: a. Upper 1/3 of humerus b. Intertubercular (bicipital) groove c. Coracobrachialis mm d. Triceps brachii mm. 6. Base: a.The axillary fascia forms the base. Anteriorly, the anterior axillary fold limits it, and posteriorly, the posterior axillary fold limits it. Contents: 1. Cords and branches of the brachial plexus; 2. Axillary artery and its branches; 3. Axillary lymph nodes (5 groupssee next) 4. Adipose tissue;
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Cutaneous Innervation of the Upper Limb 8 sensory nerves supply the skin of the upper limb: 1. Supraclavicular nerve – the only one that emerges from the cervical plexus. It can be located at the lowermost border of the sternocleidomastoid muscle as it fans over the clavicle; 2. Posterior brachial cutaneous nerve – a branch of the radial nerve that emerges posteriorly between the teres major muscle and the long head of the triceps brachii muscle. It runs along the long head of the triceps brachii; 3. Posterior antebrachii cutaneous nerve – emerges from the radial nerve but runs deep to the lateral head of the triceps brachii. It emerges out of the inferior border of the lateral head of the triceps brachii and superficially crosses the anconeus muscle and the extensor digitorum muscle; 4. Superior lateral brachii cutaneous nerve – emerges out of the axillary nerve at the level of the deltoid muscle; 5. Inferior lateral brachii cutaneous nerve – emerges out of the radial nerve (or directly from the posterior antebrachial cutaneous nerve) and pierces the lateral head of the triceps brachii to supply the skin over it; 6. Lateral antebrachial cutaneous nerve – emerges from the musculocutaneous nerve and runs between the biceps brachii muscle and the brachialis muscle. It leaves the brachialis muscle to run superficially on the brachioradialis muscle; 7. Medial brachial cutaneous nerve – emerges out of the medial cord of the brachial plexus (T1) and runs medially on the long head of the triceps brachii; 8. Medial antebrachial cutaneous nerve – emerges from the medial cord of the brachial plexus (C8, T1) and runs parallel to the ulnar nerve. It is best located at the level of the medial epicondyle of the humerus;
Axillary Lymph Nodes 1. Central axillary nodes are located in the center of the axillary fossa; 2. Apical axillary nodes can be found at the apex of the axillary fossa; 3. Lateral pectoral nodes are at the lateral edge of the pectoralis major muscle; 4. Interpectoral nodes are sandwiched between the pectoralis major and minor muscles; 5. Subscapular nodes are below the subscapularis muscle.
Superficial Veins of the Upper Limb Remember: when you talk about veins, they do not emerge from, or branch out from any other vein. The veins start in the capillary beds given by the diminishing arteries. The capillaries collect to venules
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that in turn collect into veins. The veins unite at some point to enter the right atrium of the heart as a single vein – either the superior vena cava or the inferior vena cava. Basilica vein The basilica vein originates at the subcutaneous venous network at the dorsum of the hand. It ascends along the medial side of the forearm. Proximal to the level of the elbow crease, it runs along the medial bicipital groove. At the level of the lower 2/3-upper 1/3 it pierces the brachial fascia at the hiatus basilicus to enter the medial bicipital groove. It then opens into the brachial vein. At the hiatus basilicus, the medial brachial and antebrachial cutaneous nerves exit to the subcutaneous space. Cephalic vein The cephalic vein originates from the same venous network and ascends along the anterolateral border of the forearm. Proximal to the level of the elbow crease, it ascends along the lateral bicipital groove. It then enters the deltoidopectoral groove (a groove created by the bordering of the pectoralis major and the deltoid muscles) and pierces 2 fasciae: the deltoidopectoral fascia and the clavipectoral fascia. It enters the axillary fossa to open into the axillary vein. At the level of the elbow crease the median cubital vein is found. This vein is in effect an anastomosis between the cephalic vein and the basilica vein. It may assume a V-shape or an M-shape. To the apex of the V (or to the inferior apex of the M) the median the median antebrachial vein opens. Clinical Correlate The median cubital vein is the vein from which blood is drawn Medial Bicipital Groove This groove is created by the bordering of the triceps brachii muscle and the biceps brachii muscle on the medial side of the arm. Contents: 1. Musculocutaneous nerve 2. Deep brachial artery 3. Brachial artery and vein 4. Median nerve and ulnar nerve 5. Basilic vein 6. Medial brachial & antebrachial cutaneous nerves
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Lateral Bicipital Groove This groove is created by the bordering of the biceps brachii and the triceps brachii on the lateral side of the arm. Contents: 1. Lateral brachial cutaneous nerve 2. Cephalic vein Cubital Fossa The cubital fossa is located at the anterior aspect of the elbow. It is triangular is shape, the apex of which point to the hand. Borders: Medial: pronator teres muscle; Lateral: brachioradialis muscle; Superior: an imaginary line connecting the epicondyles of the humerus (akternatively, the elbow crease) Floor: supinator and brachialis muscles; Roof: cubital fascia and aponeuroses of the biceps brachii muscle; Contents (7 items): 1. Median nerve – most medial 2. Cubital artery – this is nothing else but the continuation of the brachial artery. When the brachial artery is in the cubital fossa it is simply termed cubital artey. Within the fossa the cubital artery divides into the radial artery and the ulnar artery. 3. Radial artery – runs with the superficial branch of the radial nerve and is easily located underneath the brachioradialis muscle. 4. Ulnar artery – exits the fossa deeply and runs under the flexor carpi ulnaris muscle. 5. Branches of the brachial, radial and ulnar arteries. These branches form anastomoses around the elbow called rete articulare cubiti (you will not find it in your atlases – google it). 6. Deep branch of the radial nerve – this is the only branch of the radial nerve that enter the cubital fossa (otherwise the nerve is completely underneath the brachioradialis muscle). The deep branch of the radial nerve pierces the supinator to relocate to the posterior aspect of the forearm (it supplies the extensors of the forearm). 7. Cubital lymph nodes 8. The median cubital vein is outside the fossa and thus not part of its contents.
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Carpal Tunnel This canal is located at the wrist. Borders: Medial: medial carpal eminence (formed by the pisiform and the hook of the hamate) Lateral: lateral carpal eminence (formed by the scaphoid and the trapezium) Anterior (roof): flexor retinaculum Posterior (floor): capal bones. Contents: 1. median nerve (located between the tendon of the flexor digitorum superficialis and the flexor digitorum profundus 2. tendons of the flexor digitorum superficialis and profundus 3. tendon of flexor pollicis longus l ongus
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The flexor retinaculum splits and forms a separate chamber in which the tendon of flexor carpi radialis passes. 6. Clinical Correlate Carpal Tunnel Syndrome (CTS) CTS result from any lesion that significantly reduces the size of the carpal tunnel, or, more commonly, increases the size of some of the nine structures that pass through it (e.g. inflammation of the synovial sheath). Fluid retention, infection, and excessive exercise of the fingers may cause swelling of the tendons or their synovial sheaths. The median nerve is the most sensitive structure in the tunnel. Any impairment to this nerve results in paresthesia (tingling), hypoesthesia (diminished sensation) or anesthesia (absence of sensation) in the lateral 3 and a half digits. If the cause is not alleviated, progressive loss of coordination and strength in the thumb occur. As the condition progresses, sensory changes radiate into the forearm and axilla. Treatment: physiotherapy (first line) and surgery (second line).
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Blood Vessels and Nerves 1. Axillary artery: this artery is found in the axillary fossa and is surrounded by the cords of the brachial plexus. It has 3 parts that will be discussed later. 2. Brachial artery (the continuation of the axillary artery). It is located at the medial bicipital groove. The ulnar
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nerve and the radial nerve accompany it. Radial artery: originates from the brachial artery (cubital artery) at the cubital fossa. It runs underneath the brachioradialis along with the superficial branch of the radial nerve. It enters the snuffbox (see page 15) to appear at the dorsum of the hand. It pierces the adductor pollicis muscle and reaches the palm to form the deep palmar arch. Ulnar artery: originates from the cubital artery too, and runs underneath the flexor carpi ulnaris muscle along the ulnar nerve. Medial cord of the brachial plexus is located on the medial side of the axillary artery. If you trace the ulnar nerve and follow it upwards, it will lead you to the medial cord. Lateral cord and the brachial plexus: it is located on the lateral side of the brachial artery. If you trace the musculocutaneous nerve and follow it upwards, it will lead you to the lateral cord. Posterior cord of the brachial plexus: it is located behind the axillary artery. If you trace the radial nerve and follow it upwards, it will lead you to the posterior cord. Median nerve: it originates from the medial and lateral cord of the brachial plexus. It runs along the medial bicipital groove and enters the cubital fossa. Ulnar nerve: originates from the medial cord of the brachial plexus. It runs along the medial bicipital groove. It goes behind the medial epicondyle on the ulnar groove. When it is compressed there, it results in ulnar tunnel syndrome. syndrome . Radial nerve: it originates from the posterior cord of the brachial plexus. It exits the axillary fossa along the posterior wall. It runs underneath the lateral head of the triceps brachii, where it winds around the shaft of the humerus in the radial groove. It reaches the antero-lateral side of the arm and runs underneath the brachioradialis. Here, it divides into 2 branches:
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a. Superficial branch: first it runs under the brachioradialis muscle and then under the flexir carpi radialis. The radial artery accompanies it. The nerve reaches the dorsum of the hand and supplies the skin of the hand; b. Deep branch: pierces the supinator muscle to reach the posterior side of the forearm. Here it branches again into several branches that supply the extensors of the hand. 11. Musculocutaneous nerve: it originates from the lateral cord of the brachial plexus and pierces the coracobrachialis muscle. It innervates the flexors of the arm. The terminal branch continues along the lateral bicipital groove to become the lateral antebrachial cutaneous nerve. 12. Axillary nerve: it originates from the posterior cord of the brachial plexus. It runs posteriorly to exit the axillary fossa from the quadrangular space. Here, the posterior circumflex humeral artery accompanies it.
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and a half fingers (except for the fingertips). 4. Ulnar nerve: the main part of the ulnar nerve innervates: a.Flexor carpi ulnaris mm. b. Ulnar head of the flexor digitorum profundus; c.The deep branch supplies all hypothenar muscles, all mesothenar muscles (except for the first 2 lumbricals and the adductor pollicis muscle). d. The superficial branch supplies the palmar side of the last 1 and a half fingers and the dorsal aspect of the last 1 and a half fingers (except for the fingertips of rd th the 3 digit and half of the 4 fingertip). 5. Axillary nerve: supplies the muscles of the shoulder: the deltoid mm, the supraspinatus mm. and infraspinatus mm. Clinical Correlate Guyon Tunnel Syndrome Compression of the ulnar nerve may occur at the wrist where is passes between the pisiform and the hook of the hamate. The depression between these bones is converted by the pisohamate ligament into an osseofibrous tunnel, the ulnar canal (Guyon tunnel). Guyon Tunnel syndrome is manifest by hypoesthesia in the medial one and a half fingers and weakness of the intrinsic muscles of the hand. "Clawing" of th th the 4 and 5 fingers (hyperextension at the MPJ with flexion at the PIP joint) may occur, but – in contradistinction to proximal ulnar nerve injury – their ability to flex is unaffected and there is no radial deviation of the hand.
Innervation Regions of the Nerves 1. Median nerve: it supplies all the flexors of the forearm except flexor carpi ulnaris and the ulnar head of the flexor digitorum profundus; a.It innervates all thenar muscles, except the adductor pollicis muscle. It also innervates the first 2 lumbricals. b. It supplies the skin of the palmar side of the first 3 and a half fingers, and the fingertips of the dorsal side of the first 3 and a half fingers. 2. Musculocutaneous nerve: a.Supplies all flexors of the arm; b. Its terminal branch (the lateral antebarchial cutaneous nerve) supplies the skin at the lateral aspect of the forearm. 3. Radial nerve: a.The main trunk supplies all extensors of the arm; b. The deep branch innervates all extensors of the forearm; c.The superficial branch supplies the skin at the dorsal aspect of the 2
Muscles of the Upper Limb For this section, please consult the tables in the Moore. NOTE: NOTE: you should memorize ALL muscles, including their origins and insertions . However, it is not necessary to know the exact origin/insertion in a particular bone (for example, the serratus anterior originates from the external surfaces of the lateral parts of ribs 1-8. here, it would be sufficient to know that the origin is the first 8 ribs).
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cutaneous nerves. nerves. The superior trunk gives off the suprascapular nerve; nerve; the root of C5 gives off the dorsal scapular nerve, nerve, and the roots of C5, C6 and C7 give off the long thoracic nerve. nerve. I'm sorry, but you have to remember them all…!
The following tables should be learned: Moore, pages: 752, 755, 788-789, 804-805, 808-809, 832-833. NOTE: the tables are arranged according to muscle, origin, insertion, innervation, and action. HOWEVER, you should know the alternative groupings of these columns. That is, you might be asked to list all muscles innervated by the radial nerve, to list all muscles that abduct the shoulder, or all muscles that originate from or insert into the coracoid process. Don't say I didn't warn you…
Axillary Artery The aorta leaves the left ventricle and gives off 3 arteries at the aortic arch: the brachiocephalic trunk, the left common carotid artery and the left subclavian. The brachiocephalic trunk gives off the right common carotid artery and the right subclavian artery. A common question in the oral exam is: what's the difference between an artery and a trunk? The answer is that a trunk gives off the main arteries (just like a trunk of a tree) – it does not have any side branches on the way! An artery gives off branches along its course. The axillary artery is the continuation of the subclavian artery. The subclavian artery simply changes its name when it enters the axillary fossa. When the axillary artery leaves the axillary fossa it will, too, change its name to brachial artery. The axillary artery is enclosed in a strong connective tissue sheath – the axillary sheath. The axillary artery has 3 divisions: the first one is proximal to the pectoralis minor, minor, the second division is behind the pectoralis minor, and the third one is distal to this muscle. Now it's easy: The first division has 1 branch, the second division has 2 branches, and the third division has 3 branches. The first division gives off the superior thoracic artery. You can find this artery right beneath the clavicle running downwards. The second division gives off the thoracoacromial artery and the lateral thoracic artery. The thoracoacromial has 4 branches: pectoral branch, acromial branch, clavicular branch and deltoid branch. The lateral thoracic branch runs along the lateral border of the pectoralis minor (don't confuse it with the pectoral branch of the thoracoacromial artery which runs underneath the pectoralis minor and between the pectoralis major and minor muscles.
The Brachial Plexus The brachial plexus is one of the 4 plexuses of the human body. It originates from the ventral rami of C5 to T1 nerve roots. It has 5 components: Roots, Trunks, Divisions, Cords, Branches (the order of these structures can be memorized by the mnemonics: Robert Tylor Drinks Cold Beer). Now, open the atlas, follow these explanations, and make sure you know how to draw the brachial plexus! (It doesn't have to be Picasso quality, but a schematic one would suffice). 1. Roots: the ventral roots of C5-T1 form the brachial plexus; 2. Trunks: there are 3 trunks – superior (the union of C5-C6), middle (C7) and inferior (the union of C8-T1); 3. Divisions: each trunk divides into an anterior division and a posterior one. 4. Cords: the lateral cord is formed by the union of anterior divisions of the superior trunk and the middle trunk); the posterior divisions of all trunks cord; the unite to form the posterior cord; anterior division of the inferior trunk cord. forms the medial cord. 5. Branches: the terminal branches are the musculocutaneous nerve; axillary nerve; radial nerve; median nerve (co-contribution of the lateral and medial cords); and ulnar nerve. The lateral cord gives off the lateral pectoral nerve; nerve; the posterior cord gives off the lower subscapular nerve, the thoracodorsal nerve, and nerve. The the upper subscapular nerve. medial cord gives off the medial brachial and antebrachial
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The third division runs from the lateral border of the pectoralis minor to the inferior border of the teres minor muscle. It gives off the anterior circumflex humeral artery, the posterior circumflex humeral artery, and the subscapular artery. The anterior and posterior circumflex humeral arteries "hug" the neck of the humerus. In order to locate the posterior one, you need to displace the anterior one (upwards or downwards). Another distinguishing feature between these two is their diameter (the anterior one is 1 mm in diameter and the posterior one is 3 times bigger – 3 mm. ). These are not simply for your convenience, but you will be asked about it! The subscapular artery is short and gives off 2 branches: the circumflex scapular artery and the thoracodorsal artery. The thoracodorsal artery descends along the lateral margin of the scapula towards the inferior angle of the scapula. The circumflex scapular artery exits the axillary fossa through the medial axillary hiatus, runs behind the scapula and unites with the suprascapular artery (which is a branch of the subclavian artery). Thus, we have an anastomosis here between the axillary artery and the subclavian artery.
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The circumflex scapular artery exits the axillary fossa through this space. The Connective Tissue Spaces of the Palm The palm has 4 connective tissue spaces: Thenar space; adductor space, mesothenar space; and hypothenar space. These spaces are formed by the insertion of the palmar aponeuroses on the metacarpal bones. The thenar space is the muscular elevation of the thumb. It has these structures: Muscles: 1. Adductor pollicis brevis; 2. Flexor pollicis brevis; and 3. Opponens pollicis Between the superficial and the deep head of the flexor pollicis brevis we can find the tendon of the flexor pollicis longus. Nerves: 1. Branches of the median nerve. Arteries: 1. Princeps pollicis artery; 2. Branches of radial artery. The mesothenar space is at the middle of the palm. It contains: 1. palmar aponeuroses; 2. end branches of the common digital arteries and nerves; 3. the proper digital arteries and nerves; 4. tendons of the flexor digitorum superficialis; 5. superficial palmar arch; 6. ulnar nerve; 7. tendons of the flexor digitoru profundus and the 4 lumbricals; 8. deep palmar arch and palmar interosseus arteries; 9. the 3 palmar interosseus muscles; The hypothenar space is the muscular elevation associated with the pinky finger. It has: 1. adductor digiti minimi; 2. flexor digiti minimi brevis; and 3. opponens digiti minimi;
Lateral Axillary Hiatus (= Quadrangular Space) This hiatus is located at the posterior wall of the axillary fossa. Borders: Superior: teres minor muscle; Inferior: teres major muscle; Medial: long head of the triceps; Lateral: upper 1/3 of the humerus; Contents: The posterior circumflex humeral artery and the axillary nerve exit the axillary fossa through this space. Medial Axillary Hiatus (= Triangular Space) This space is located at the posterior wall of the axillary fossa. Borders: Superior: teres minor muscle; Inferior: teres major muscle; Lateral: long head of the triceps; Contents:
Arterial Anastomoses 1. At the shoulder joint: a.Between the anterior and posterior circumflex humeral arteries; b. Between the circumflex scapular and suprascapular arteries. 2. At the elbow joint:
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a. Rete articulare cubiti (formed by the radial and ulnar collateral arteries and the ulnar and radial recurrent arteries). At the wrist joint a. Between the dorsal carpal branches of the radial and ulnar arteries; b. Between the palmar carpal branches of the radial and ulnar arteries. At the hand a.Superficial palmar arch between the main trunk of the ulnar artery and the palmar branch of the radial artery; b. Deep palmar branch between the main trunk of the radial artery and the deep palmar branch of the ulnar artery; c.Between the palmar interosseal arteries and the palmar common digital arteries. At the dorsum of the hand a.The dorsal arterial arch of the hand between the dorsal branches of the radial and ulnar arteries. At the fingers a.Between the palmar and dorsal proper digital arteries.
Snuff Box (Radial Fossa or Fossa of Tabaccie) This fossa is located at the radial aspect of the proximal part of the hand. It is a depression between the tendon of the extensor pollicis longus, and the tendon of the extensor pollicis brevis and the adductor pollicis longus. The scaphoid and the trapezium form the floor. (the name originates from the use of this surface for placing and then snorting powdered tobacco, or "snuff"). Contents: The radial artery.
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