Advanced Human Anatomy: Upper Limbs

• Advanced Human Anatomy details the bony structure, musculature, arterial supply, and innervation of the upper limbs.

Bony Structures of Upper Limbs

• The upper limbs consist of the clavicle, scapula, humerus, radius, ulna, carpal bones, metacarpal bones, and phalanges.

Clavicle

• The clavicle is a cylindrical long bone which lies subcutaneously throughout its length with a slight S-shaped curve.
• It lacks a medullary cavity.
• The clavicle has one shaft and two ends.
• The medial part articulates with the sternum.
• The lateral portion articulates with the acromian process of the scapula.

Scapula

• The scapula extends from the 2nd to 7th rib.
• It's a flat and triangular bone.
• The anterior surface is the costal surface.
• The dorsal or posterior surface contains the spine of the scapula.
• It features superior, medial, and lateral borders and superior and inferior angles.
• The acromion articulates with the clavicle.
• The glenoid cavity articulates with the head of the humerus.
• The coracoid process projects upward and provides attachment for muscles and ligaments
• It has a shallow glenoid cavity

Humerus

• The humerus is the largest and longest bone of the upper limb.
• The anatomical neck is present
• The surgical neck is where the head meets the shaft.
• It has a body and two ends.
• Features include head, greater and lesser tubercle, and intertubercular sulcus or bicipital groove.
• The lower end is flat with two articular surfaces.
• The capitulum is for the head of the radius.
• The trochlea articulates with the trochlear notch of the ulna.
• Lateral and medial epicondyles are for muscle and ligament attachment.
• The radial fossa accommodates the radial head when the elbow is flexed.
• The coronoid fossa accommodates the coronoid process of the ulna during movement.
• The olecranon fossa is located posteriorly for the olecranon process of the ulna during elbow extension.

Humerus Fractures and Nerve Injury

• Surgical neck fractures can cause axillary nerve injury
• Shaft fractures can cause radial nerve injury
• Supracondylar fractures can cause median nerve injury

Radius and Ulna

• Key features of the radius and ulna include the trochlear notch, olecranon process, coronoid process, and radial tuberosity.

Radius Fracture

• A fracture of the distal end of the radius is known as Colle's fracture, often due to a fall on an outstretched hand in patients over 50 years old
• The distal fragment of the radius is pulled posteriorly and superiorly.
• The distal articular surface is directed posteriorly.
• The posterior displacement produces a posterior bump.
• The deformity is referred to as a "dinner-fork deformity."
• Smith's fracture is a reversed Colle's fracture where the distal segment is displaced anteriorly.

Carpal Bones

• There are 8 carpal bones: scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate, and hamate.
• From lateral to medial the proximal row: scaphoid, lunate, triquetral & pisiform.
• From lateral to medial the distal row consists of trapezium, trapezoid, capitate & hamate.
• Scaphoid fractures are the most common.

Scaphoid Bone Fracture

• Scaphoid bone fractures are common in young adults
• The fracture line passes through the narrowest part of the bone.
• If fragments do not unite, permanent pain and weakness at the wrist can occur
• Deep tenderness in the anatomical snuffbox after a fall on an outstretched hand in a young adult indicate a fracture of the scaphoid bone.

Elbow Dislocations Vs 'Pulled Elbow'

• Elbow dislocations are common and typically posterior.
• Elbow dislocations occur more often in children due to a fall on an outstretched hand.
• The distal end of the humerus is pushed anterior through the weak part of the capsule.
• A pulled elbow occurs in children when the child is lifted by the upper limb.
• The radial head is pulled out of the annular ligament.

Elbow Injuries

• Tennis elbow is caused by a partial tear or degeneration of the origin of superficial extensor muscles attached to the lateral epicondyle
• Tennis elbow results from excessive use of these muscles in tennis, violin, and housework.
• The injury causes pain and tenderness over the lateral epicondyle that radiates to the lateral side of the forearm.
• Golfer's elbow (medial epicondylitis) is caused by a partial tear or degeneration of the origin of superficial flexor muscles attached to the medial epicondyle.
• It results from excessive use of the flexor muscles, such as in playing golf
• Golfer's Elbow results in pain and tenderness over the medial epicondyle that radiates to the medial side of the forearm.

Bones of the Hand

• The bones of the hand are the carpals, metacarpals, and phalanges.
• From lateral to medial, the proximal carpal row includes the scaphoid, lunate, triquetral, and pisiform bones
• The distal row includes the trapezium, trapezoid, capitate, and hamate.

Muscles that Abduct the Upper Arm

• The deltoid origin is from lateral 1/3rd of clavicle, acromion process and spine of scapula.
• The Deltoid's insertion is into the deltoid tuberosity of humerus.
• The deltoid muscle acts as primary abductor of shoulder joint, and rotator of humerus; its nerve supply is the axillary nerve.
• The supraspinatus muscle is deep to the trapezius.
• It arises from the supraspinatus fossa of scapula.
• It's inserted into greater tubercle of humerus.
• The supraspinatus muscle stabilizes shoulder joint and abducts the humerus; its nerve supply is the suprascapular nerve

Muscles that Adduct the Upper Arm

• Muscles that adduct the upper arm include the pectoralis major, latissimus dorsi, teres major, and subscapularis.
• The pectoralis major originates from the sternal half of the clavicle, the upper half of the sternum and the aponeurosis of the external oblique muscle.
• The pectoralis major inserts on the lateral lip of the intertubercular sulcus and functions to adduct, medially rotate, and flex the shoulder; it is innervated by the medial and lateral pectoral nerves (C5-8, T1).
• The latissimus dorsi is a broad, flat triangular muscle in the lower back.
• It is overlapped by the lower part of the trapezius.
• Its origin is from the lumbar fascia, spines of the lower six thoracic vertebrae, lower three or four ribs, and the inferior angle of the scapula, before inserting on the intertubercular groove of the humerus.
• The teres major originates from the dorsal surface of the inferior angle of the scapula and inserts on the medial lip of the intertubercular groove of the humerus.
• It is innervated by the lower subscapular nerve (C6, C7) and extends the arm from a flexed position, adducts, and medially rotates the arm
• The subscapularis originates from the medial 2/3 of the subscapular fossa and the lateral border of the scapula, inserting on the lesser tubercle of the humerus.
• It is innervated by the upper and lower subscapular nerves (C5, C6) and stabilizes the shoulder, preventing anterior displacement while mediating rotation and adduction of arm.
• The infraspinatus originates from the infraspinatous fossa of the scapula and inserts on the middle facet of the greater tubercle of the humerus.
• It is innervated by the suprascapular nerve of the brachial plexus (C5, C6).
• The infraspinatus is used in lat. rotation of shoulder and to strengthen and brace the head of the humerus.

Rotator Cuff Muscles

• The rotator cuff consists of the tendons of the subscapularis, supraspinatus, infraspinatus, and teres minor muscles.
• These muscles fuse to the shoulder joint capsule and help stabilize it.

Muscles of the Anterior Forearm

• The Biceps brachii long head originates from the supra glenoid tubercle of the scapula.
• The short head originates from the apex of the coracoid process.
• Inserts radially on the radial tuberosity.
• The biceps brachii is a powerful supintator of the forearm and a flexor of the supinated forearm; receives nerve signals via musculocutaneous.N (c5,c6)
• The brachialis origin: distal half of the anterior humerus
• Inserts to the coronoid process, tuberosity of ulna
• The brachialis is a powerful flexor of the forearm; recieves nerve signal Musculocutaneous.N (C5, C6, C7)
• The coracobrachialis muscle runs in an elongated shape in superomedial section runs from the scapula acoraoid process to insert on the medial shaft of the Humerus
• The coracobrachialis flexes the arms, via musculocutaneous nerve.

Posterior Extensor Muscle of Arm

• The Triceps brachii have 3 heads
• The long head originates from the infraglenoid tubercle of the scapula
• The lateral head originates from upper half of posterior surface of shaft of humerus
• The Medial Head: Lower half of posterior surface of shaft of humerus
• All fiibers instert on the olecranon process of ulna and act as enxtensor
• The triceps brachii reveices is nerve signals vis radial nerve

Muscles that Move the Hand

• Anterior flexor pronator group
• Flexor carpi radialis flexes and abducts the hand
• Palmaris longus (flexes the hand)
• Flexor carpi ulnaris (flexes and adduct the hand
• Proneter teres (pronates the hand)
• Brachioradialis
• Flexor digitorium superficialis
• Flexor pollicis longus
• Pronator quadratus
• The humeral head of flexor carpi ulnaris originates from the medial epicondyle
• The ulnar head is on the median margin of the olecrenon on the posterior border of of ulna. INserts on flexor retinaculum
• the flexor carpi ularis nerve suuply comes from the ulnar nerve

Wrist

• base of the second metacarpal. The third metacarpal receives the insertion on the base. Receives it's nervous signal via the median nerve
• Palmaris longus. Insertion on anterior aspect of distal flex retinaculum Nervous signal via the median .
• Extensor carpi radialis. Extends and abducts the hand
• Extensor carpi ulnaris. - Extends and adduct the hand
• Extensor digitorium. Extends the phalanges
• Brachioradialis- acc flexor of elbow; recieves nerve signals Radial N
• Volkmann's Ischaemic Contracture involves the distal humerus bones of children
• It involves spasm of flexor muscles reducing flow for flexor muscles and extensor muscles
• Results in forearm contractions

Intrinsic Muscles of the Fingers and Hand

• palmer flexors are in the group: thernar
• Groups of Dorsal Extentors are: thenar extensor
• Dupuytren's Contracture Is a localized contracture on the fingers. Can lead to Vascular constrictions
• Pulp-Space Infection This is pus in the fintertips and more often gathers than anywhere else in the hand Can happen on thumb and index fingers

Upper Arteries

• THE AXILLARY ARTERY begins at the outer border of the 1st rib as a continuation of the Subclavian A. & ends at the lower border of the teres major M. by becoming the Brachial A.
• The pectoralis divides the axillary artery into three part. it lies very between the axillary vein.
• The * thesub scapular & circumflex

Anastomosis of Scalpula

• the scapular A which runs to the infraspinous fossa

The Brachial Artery

• It begins at the teres major and ends at the the radius by dividing onto Radial and Unar A. LIES IMMEDIATLY. Suupllies all arm.

Radial Artery

• The radial Begins: in the cubital fossa at the neck of the radius. Runs lateraly with multiple branches At the lower end of the radius, it leaves the front of the forearm & turns backward round the lateral border of the wrist, below the styloid process of the radius & enter the anatomical snub

Unlar Artery

• Begins in the cubital fossa at the opposite neck of the radius.

The Superficial Palmer Arch

• It is formed mainly by the ulnar
• The Deep Palmer Arterial.
• The radial A. with the deep palmer branch of the ulnar A.

Recap of Vessels

• subclavian artery. Then the axillary
• The brachial Radial and ulnar
• Ulnar arery connects to comon intereous

Vein System

• Vv. start as V
• The deep veins are the veins which accompany Main Aa. And has superworld

Vein of the Upper Extremity

• Blood vessels of upper. Consisted of dorsal and cephalic viens. As well

Clinical Vessels

• Oftical Vessels
• blood transfer for intravenus

Brachial Pexus

• It is a complex arrangement of the that supplies skin. It happens at the anterior Spinal.

Upper Limb

• C6
• C7
• C8
• T1
• 1+T2

Cubital Fossa

• Superior
• lateral Median nerves, superal

Innervation

• Arises from cord and cord

• Ulnar

• And more fingers .with it the brance=pst N 3 an 1/2 is innervated Medial1 & half figer is innervalte

Nerves of the Upper Limbs

• The lateral cord includes axillary and the cord continues as the radialN. THE medial Cord the