Bones of the Upper Limb 2024 PDF

Bones of the upper limb Ref: Grays Anatomy for student, chapter 7 Snell Clinical Anatomy by region, chapter 9 Last’s anatomy (11th, ed) chapter 2 Dr. Hasnaa Ali ASSOC. Professor in Anatomy, PNU  Learning objectives Identify bones forming the skeleton of the upper l...

Bones of the upper limb Ref: Grays Anatomy for student, chapter 7 Snell Clinical Anatomy by region, chapter 9 Last’s anatomy (11th, ed) chapter 2 Dr. Hasnaa Ali ASSOC. Professor in Anatomy, PNU  Learning objectives Identify bones forming the skeleton of the upper limb Describe gross anatomical features of bones of the upper limb (Clavicle, Scapula, Humerus, Radius& Ulna) List articulations between bones of the upper limb  Bones of the upper limb Bones of the shoulder girdle (Clavicle, Scapula) Humerus Radius Ulna Bones of the Hand (Carpals, Metacarpals, Phalanges)  Clavicle https://youtu.be/bLXPHDTZX7w?si=TZ19V3D15c5 zZ4jD  Clavicle The clavicle is the only bony attachment between the trunk and the upper limb.  It lies horizontally.  It is palpable along its entire length.  It has a gentle S-shaped contour: - The medial part : convex forward - The lateral part: concave forward It has 2 ends (medial & lateral), 2 surfaces (superior & inferior).  It has 2 ends 1- The lateral (acromial) end: flat, has articular facet that articulates with acromial process to form acromioclavicular joint. 2- The medial (sternal) end: quadrangular, has articular facet that articulates with sternum and 1st costal cartilage to form sternoclavicular joint. It has 2 surfaces: 1- The superior surface: is smooth 2- The inferior surface has the following features: In the lateral third of the clavicle there is a tubercle (the Conoid tubercle) and lateral roughening line (the trapezoid line). ro ove vi an g In the middle part there is Sub c l a groove for subclavius muscle. Important Notes About Clavicle The ONLY long bone that lies HORIZENTALLY The ONLY long bone that has NO Medullary cavity The FIRST bone to ossify in the fetal life (5 th, week) It ossifies in membrane (MEBRANOUS) not cartilaginous It is commonly fractured bone  Scapula https://youtu.be/70j06vbmclM?si=oTvACOkzD9uVyzhX  Scapula The scapula is a flat triangular bone with Posterior view Three angles (lateral, superior, and inferior); Three borders (superior, lateral, and medial); Two surfaces (costal and posterior); and Three processes (acromion, spine, and coracoid) Anterior view  Scapula  The lateral angle of the scapula is marked by comma- shaped glenoid cavity, which articulates with the head of the humerus to form the glenohumeral (shoulder) joint.  Infraglenoid tubercle: rough triangular area inferior to the glenoid cavity  Supraglenoid tubercle: A less distinct area superior to the glenoid cavity. Lateral view  The superior border: is thin and sharp Has suprascapular notch in its lateral part The medial border: is thin and vertical The lateral border: is thick and oblique  The posterior surface is divided by spine into: Supraspinous fossa (above) and Infraspinous fossa (below).  The anterior (Costal) surface Has concave subscapular fossa. Anterior view The 3 processes: 1- The spine - A triangular process on posterior surface - Its posterior border is called crest of the spine. ??? Spinoglenoid notch It is between the glenoid cavity and the spine 2- The acromion (tip of shoulder) - An anterolateral projection of the spine - Articulates with the clavicle to form acromioclavicular joint. 3- The coracoid process, A hook-like structure at the lateral end of the upper border.  Humerus It is a long bone, has (upper end, shaft and lower end) Upper end Shaft Lower end https://youtu.be/A7UMQh4LSGU?si=bbNrPWEoM_HH1Oo Y  Humerus The upper (proximal) end is composed of 6 parts: 1- The head: - Is half-spherical in shape& projects medially - - Articulates with glenoid cavity to form shoulder joint. 2- The anatomical neck is constriction immediately distal to the head. 3- The greater tubercle - Is lateral in position. - Its superior and posterior surface are marked by 3 facets for muscle attachment: Sup facet: for Supraspinatus ms Middle facet: for Infraspinatus ms Inf facet: for Teres minor 4- The lesser tubercle is anterior in position 5- Intertubercular sulcus (bicipital groove) separates the lesser and greater tubercles 6- The surgical neck constriction between proximal part of the humerus and the narrower shaft. - It is a common site for fracture (axillary N. and Post. Circumflex humeral art. are related to it) 0. The shaft  Has 3 borders: anterior, lateral, and medial borders;  Lateral supracondylar ridge: is the distal part of the lateral border  Medial supracondylar ridge: is the distal part of the medial border.  Has 3 surfaces: anterolateral, anteromedial, and posterior surfaces  Features of Humerus Shaft: 1- Radial groove: shallow groove lies in the middle part of the posterior surface (related to radial N.) 2- Deltoid tuberosity: V- shaped rough area on the middle of the lateral surface of humerus. ( site for insertion of Deltoid ms.) The lower (distal) end of the humerus: It has 2 articular parts, 2 epicondyles, and 3 fossae, as follows  The two articular parts: 1- Capitulum lies laterally & articulates with the radius. 2- Trochlea lies medially & articulates with the ulna.  The three fossae 3 1- The radial fossa is superior to the capitulum on the anterior surface of the humerus. 2- The coronoid fossa is superior to the trochlea on the anterior surface of the humerus. 3- The olecranon fossa is superior to the trochlea on the posterior surface of the humerus. The two epicondyles: medial epicondyle, Is the major palpable landmark on the medial T: Trochlea C: Capitulum side of the elbow 1: coronoid fossa 2: radial fossa lateral epicondyle 3: olecranon fossa 4: medial epicondyle Is less pronounced than the medial epicondyle. 5: lateral epicondyle  Bones of Forearm Elbow joint Superior radio-ulnar joint S L  Radius The radius is a long bone, has upper (proximal), end, shaft and lower (distal) end. RT  Radius The proximal end of the radius consists of: 1- The head (disc-shaped) - Its superior surface articulates with the RT capitulum of the humerus to form elbow joint. - The margin of the disc articulates medially with the radial notch of the ulna to form superior radioulnar joint. 2- The neck of the radius is the narrow part between the head and radial tuberosity. 3- The radial tuberosity (RT) is a large projection on the medial surface of the radius immediately inferior to the neck. RT Shaft of radius The shaft of the radius is narrow proximally, and broader distally, it has:  Three borders (anterior, posterior, and interosseous) The anterior border: begins on the medial side of the bone as a continuation of the radial tuberosity - Its upper part cross from medial to lateral as the oblique line of the radius) The interosseous border: is the sharp medial border.  Three surfaces (anterior, posterior, and lateral). The anterior and posterior surfaces: are smooth. There is an oval roughening in the middle of the lateral surface of the radius. Post. view The distal end (broad end): 5 Surfaces Dorsa tubercle 1- anterior surface is smooth 2- posterior surface is characterized by the presence of a large dorsal tubercle 3- medial surface is marked by a facet for articulation with head of the ulna to form inferior radioulnar joint 4- lateral surface extends distally as a styloid process that is Common site of fracture as in (Colles' fractures) 5- inferior surface is marked by two facets for articulation with two carpal bones (the scaphoid and lunate) to form wrist joint.  Ulna It is a long bone, has proximal (upper) end, shaft and distal (lower) end. Its upper end has (2 notches, 2, Processes) https://youtu.be/h2ZdM1RmhLQ?si=fMSIQRbiNre 2IfN1  Ulna The proximal end of the ulna (Hook like) consists of: 1- The trochlear notch is a depression bounded by both olecranon and coronoid processes. It is the site of articulation with trochlea of humerus to form elbow joint. 2- The radial notch lies on the lateral side for articulation with the head of the radius to form superior radioulnar joint. 3- The olecranon process Can be palpated as the 'tip of the elbow.’ 4- The coronoid process projects anteriorly from the proximal end of the ulna 5- The tuberosity of ulna is rough area on anterior surface of the coronoid process. 6- Supinator fossa is a fossa that lies inferior to the radial notch The posterior margin of this fossa is broadened to form the supinator crest. The shaft of the ulna: It has:  Three borders (anterior, posterior, and Posterior border interosseous) The interosseous border is sharp lateral border, it is the attachment site for the interosseous membrane, which joins the ulna to the radius  Three surfaces (anterior, posterior, and medial). The distal end of the ulna is composed of: 1- Head is rounded projection, that articulates with radius to form inferior radioulnar joint. 2- Styloid process lies dorsomedially  Bones of the hand ps://youtu.be/vFTdwMb56aU?si=rFbGW1V_m sxXoi  Bones of the hand There are three groups of bones in the hand: (Carpals, Metacarpals, Phalanges) 1- Eight carpal bones are the bones of the wrist 2- Five metacarpals (I to V) are the bones of the metacarpus. 3- Phalanges are the bones of the digits -the thumb has only two (proximal & distal) , the rest of the digits have three (proximal, middle, distal).  The carpal bones of the wrist  are arranged in two rows, a proximal and a distal row, each consisting of four bones Proximal row From (lateral to medial )consists of:  Scaphoid  Lunate  Triquetrum  Pisiform Distal row From (lateral to medial) consists of  Trapezium  Trapezoid  Capitate  Hamate A patient presents with a complaint of persistent pain and limited range of motion in their right shoulder following a recent fall. As a medical professional, you suspect a potential fracture of the humerus bone. To confirm your suspicion, you order an X-ray examination. Which one of the following features might be affected? A) Greater Tubercle B) Olecranon Process C) Trochlea D) Coronoid Process A patient arrives at the emergency room after a fall on their outstretched hand. They complain of severe pain in the wrist, inability to grasp objects, and a visible deformity in their forearm. You suspect a possible fracture of the radius. In the context of this clinical scenario, which specific anatomical features of the radius bone would you examine in the patient's X-ray to assess for a fracture, and why are these features important in diagnosing such an injury? A) Styloid Process of the Radius B) Capitulum C) Ulnar Notch D) Glenoid Cavity  Note the following links for Exam Questions related to clinical correlation https://youtu.be/UaHaQ2Twt-g?si=xB4t0lGS8LX_rPiU https://youtu.be/SVoLJb2lmqg?si=ri8URG2F3 Nsly-9i https://youtu.be/AHtL_rMAR5Y?si=GAoqKMfICMvSL S4t