Upper Limbs Flashcards
Structural joints
- Fibrous joints: bones united by fibrous CT
- Cartilaginous joints: bones united by hyaline cartilage (synchondroses) or fibrocartilage (symphyses)
- Synovial - connected by a fibrous joint capsule lined with a synovial membrane
Functional joints
- synarthrosis: immovable
- amphiarthrosis: slightly movable
- diarthrosis: bone articulation permitting free motion in a joint
Joints
- plane - short gliding movements
- hinge - angular movements
- pivot - rotational movements
More joints
- condyloid and saddle - flexion, extension, abduction, adduction
- ball and socket - all directions of movement -
Least -> Most mobile
Most -> Least mobile
Uniaxial, Biaxial, Multiaxial
Multiaxial, Biaxial, Uniaxial
Ossification
bone-tissue formation begins in the embryo, proceeds through childhood and adolescence as the skeleton grows, slows down as an adult
Bone development 8 weeks prior
the skeleton of the human embryo consists
only of hyaline cartilage and some membranes of mesenchyme, membrane bones form from mesenchyme -> intramembranous ossification
endochondral ossification - process which all other bones inferior to the basicranial, except for the clavicles, initially develop as hyaline cartilage which is replaced
Growth of Endochondral Bones
- Bones lengthen entirely by growth of the epiphyseal plates.
- Cartilage is replaced with bone as quickly as it grows.
- Epiphyseal plates maintain constant thickness.
- The entire bone lengthens
AAAM: Pectoralis major vs. minor
Major - prime mover of arm flexion; adduction, and medial rotation of humerus.
– Medial and Lateral Pectoral Nerves
Minor - stabilizes the scapula by drawing it anteriorly and inferiorly against the thoracic wall, attaches to the coracoid process, Medial Pectoral Nerve
AAAM: Serratus Anterior and Subclavian
Serratus anterior - protracts and rotates the scapula, Long Thoracic Nerve
Subclavian - helps stabilize and depress the pectoral girdle, Nerve to Subclavius/ Subclavian Nerve
*All Innervated by Branches of the Brachial Plexus
Anterior arm compartment: Biceps brachii
O: short head: coracoid process of scapula; long head: supraglenoid tubercle of scapula
I: tuberosity of radius
A: supinates and flexes the forearm;
flexes arm
I: Musculocutaneous nerve
Anterior arm compartment: Coracobrachialis
O: coracoid process of scapula
I: medial surface of humerus
A: helps flex and adduct the arm
I: Musculocutaneous nerve
Anterior arm compartment: Brachialis
O: distal half of humerus
I: coronoid process and tuberosity of ulna
A: flexes forearm in all positions
I: Musculocutaneous nerve
Posterior arm compartment: Triceps brachii
O: long head: infraglenoid tubercle of
scapula; lateral head: posterior surface
of humerus superior to the radial
groove; medial head: P surface of humerus inferior to the radial groove
I: olecranon of ulna
A: chief forearm extensor; long head
extends the arm
I: Radial nerve
Ulna
- stabilizing bone of the forearm
- has an olecranon process for articulation with the humerus, a coronoid process at its proximal end, and a styloid process at its distal end, The ulna articulates with the trochlea of the humerus
Radius
- lateral and shorter bone
- has a head and a radial tuberosity at its proximal end, and styloid process at its distal end, the radius articulates with
the capitulum
Proximal and distal radioulnar joint
PRJ - pivot joint allows rotation of the head of the radius on the ulna during pronation and supination
DRJ - pivot joint allows rotation of the radius about the ulna during pronation and
supination
Forearm compartments
A & P, separated by an intermuscular
septum and an interosseous membrane
running between the radius and ulna, AFP muscles arise from medial epicondyle of the humerus, superficial to deep, PES muscles arise from the lateral epicondyle of the humerus, 2 groups superficial to deep
Superficial layer: fingers
Superficial layer: arise from the medial
epicondyle of humerus; innervated by the
median nerve, FCU - ulnar nerve
- Index - Pronator teres: pronates forearm
- Middle - Flexor carpi radialis: flexes and abducts hand
- Ring - Palmaris longus: flexes hand
- Pinkie - Flexor carpi ulnaris: flexes and adducts hand
Intermediate layer: flexors
- Flexor digitorum superficialis
- O: medial epicondyle of humerus and
superior half of radius - I: middle phalanges
- F: flexes middle phalanges 2-5 at proximal interphalangeal joints and flexes the proximal phalanges at the metacarpophalangeal joints
- I: median nerve
Deep layer: flexors
Flexor digitorum profundus
- I: distal phalanges
- F: flexes distal phalanges 2-5 at distal interphalangeal joints
- I: medial side: ulnar nerve; lateral side; median nerve
Deep layer: flexors part 2
Flexor pollicis longus
- F: flexes phalanges of 1st digit
- Pronator quadratus
- F: pronates forearm
Flexor retinaculum
is a ligament that runs from the hamate and pisiform bones medially to the scaphoid and trapezium bones of the wrist laterally, 9 tendons from 3 muscles
P: extensors, abductors or adductors of the hand
extensor carpi radialis longus, extensor carpi radialis brevis, extensor carpi ulnaris
P: digital extensors
extensor digitorum, extensor indicis, extensor digiti minima
P: thumb extensors or abductors
abductor pollicis longus, extensor pollicis
brevis, extensor pollicis longus, radial nerve, lateral epicondyle of humerus
P: superficial layer
Extensor carpi ulnaris: extends and adducts hand at wrist
- Extensor digitorum: extends digits 2-5 at
metacarpophalangeal joints
- Extensor carpi radialis brevis: extends and abducts hand at wrist
- Extensor carpi radialis longus: extends and abducts hand at wrist
- Brachioradialis: flexes forearm
P: Deep layer
Supinator: supinates the forearm by rotating the radius
- Extensor indicis: extends 2nd finger
- Abductor pollicis longus: abducts and extends the thumb
- Extensor pollicis longus: extends the thumb
- Extensor pollicis brevis: extends the thumb
Hand muscles
Extrinsic hand muscles have tendons that reach the hand but originate in the forearm. Intrinsic hand muscles originate and terminate in the hand
Intrinsic muscles and blood supply
- thenar (for the thumb muscles)
- hypothenar (for the 5th digit)
- short muscles of the hand (lumbricals and interossei)
radial and ulnar arteries; innervation: median and ulnar nerves
Short muscles
lumbricals and interossei
lumbricals - flex MCP joints, extends IP joints, 1&2: MN, 3&4: UN
Interossei arise from sides of metacarpals to insert on bases of proximal phalanges:
dorsal abducts: 2-4 digits
palmar adducts: 2,4,5
UN
Axilla and sheath
pyramid space inferior to glenohumeral joint, superior to skin and axillary fascia, passageway for nerves and vessels: axillary artery & vein, nerves of the cords and
branches of the brachial plexus, lymphatic vessels, and axillary lymph nodes
axillary sheath – a sleeve-like continuation of the cervical prevertebral fascia
Arm arteries
The brachial artery begins at the inferior border of teres major and ends in the cubital fossa: deep artery of the arm
(profunda brachii artery) (to the posterior arm compartment), ulnar collateral arteries (anastomoses)
Forearm arteries
Radial artery - muscles of anterior and posterior compartments, deep palmar arch
Ulnar artery - muscles of the medial side of the forearm (flexors and pronators)
and forms the superficial palmar arch
Upper limb superficial veins
Cephalic vein: preaxial compartment continues deep at the deltopectoral triangle to drain into the axillary vein.
Basilic vein: postaxial compartment; dives deep in arm to join the deep veins.
Median cubital vein: link between the
cephalic and basilic veins; crosses the cubital fossa
