upper and lower limb everything except oiai

The upper limb is designed for

Mobility and dexterity; some stability is sacrificed, especially at the shoulder

In anatomic position the palm faces

Anteriorly (supinated)

In anatomic position the elbow points

Posteriorly

Supination

Rotating the forearm so the palm faces anteriorly/upward

Pronation

Rotating the forearm so the palm faces posteriorly/downward

Radial deviation

Angling the wrist toward the radius (thumb side)

Ulnar deviation

Angling the wrist toward the ulna (little finger side)

Opposition

Moving the thumb across the palm to contact the pads of the other fingers

Circumduction

Circular motion of a limb around its point of articulation; combines flexion, extension, abduction, and adduction

Function of synovial tendon sheaths at the wrist

Provide a lubricated surface so extrinsic muscle tendons can glide smoothly across the joint

The five bone groups of the upper limb

Pectoral girdle (clavicle + scapula), humerus, radius and ulna, carpal bones, metacarpals and phalanges

Shape of the clavicle

S-shaped; forms the anterior part of the pectoral girdle

Clavicle articulates medially with

Manubrium of the sternum (sternoclavicular joint)

Clavicle articulates laterally with

Acromion of the scapula (acromioclavicular joint)

The glenoid cavity of the scapula

Shallow lateral fossa that articulates with the humeral head at the glenohumeral joint

The scapular spine separates

The supraspinous fossa (above) from the infraspinous fossa (below) on the posterior scapula

Formation of the acromion

The lateral expansion of the scapular spine projecting over the shoulder

The coracoid process projects

Anteriorly and superiorly over the glenoid cavity; attachment site for several muscles and ligaments

Anatomic neck of the humerus

Groove separating the humeral head from the greater and lesser tubercles; true anatomic boundary of the joint

Surgical neck of the humerus

Narrow shaft region immediately distal to the head and tubercles; the most common humeral fracture site

The intertubercular (bicipital) groove

Separates the greater and lesser tubercles on the anterior humerus; the biceps long head tendon travels here

Capitulum of the humerus

Lateral distal rounded surface that articulates with the radial head

Trochlea of the humerus

Medial distal pulley-shaped surface that articulates with the trochlear notch of the ulna

The olecranon fossa

Posterior depression on the distal humerus, just superior to the trochlea; receives the olecranon process during full extension

The ulnar groove of the humerus

Posterior groove between the medial epicondyle and trochlea; where the ulnar nerve passes (vulnerable to injury here)

The trochlear notch of the ulna is formed by

The olecranon posteriorly and the coronoid process anteriorly; articulates with the trochlea of the humerus

Radial notch of the ulna

Proximal lateral concavity on the ulna that articulates with the radial head (proximal radioulnar joint)

The ulna is which bone of the forearm

The medial bone

The radius is which bone of the forearm

The lateral bone

The radial tuberosity

Anterior prominence on the proximal radius; the primary attachment for the biceps brachii tendon

The radial styloid process

Distal lateral projection of the radius that extends more distally than the ulnar styloid

Proximal carpal row (lateral to medial)

Scaphoid, Lunate, Triquetrum, Pisiform

Distal carpal row (lateral to medial)

Trapezium, Trapezoid, Capitate, Hamate

How are metacarpals and phalanges numbered

1st through 5th starting with the thumb (lateral to medial in anatomic position)

Thumb interphalangeal anatomy

THUMB Only proximal and distal phalanx; NO middle phalanx and no PIP/DIP distinction

Fingers 2–5 phalangeal anatomy

Each finger has proximal, middle, and distal phalanges

The subclavian becomes the axillary artery when

It crosses the lateral border of the 1st rib

The axillary artery becomes the brachial artery when

It crosses the lower border of the teres major muscle

What divides the axillary artery into three parts

The pectoralis minor muscle, which lies anterior to its middle third

How many branches does the first part of the axillary artery have

One: the superior thoracic artery

How many branches does the second part of the axillary artery have

Two: the thoracoacromial trunk and the lateral thoracic artery

Branches of the thoracoacromial trunk

Deltoid, pectoral, clavicular, and acromial branches

What does the lateral thoracic artery supply

The lateral thoracic wall including serratus anterior and the breast

How many branches does the third part of the axillary artery have

Three: subscapular artery, anterior circumflex humeral, and posterior circumflex humeral arteries

The subscapular artery immediately divides into

The thoracodorsal artery and the circumflex scapular artery

What do the circumflex humeral arteries encircle

The surgical neck of the humerus

The brachial artery runs along what surface

Superficially along the medial border of the biceps brachii muscle

The brachial artery terminates by bifurcating into

Radial and ulnar arteries within the cubital fossa

Why do limb veins have valves

To prevent pooling of blood in the extremities and facilitate return flow to the heart

Venae comitantes are

Paired deep veins that surround and accompany arteries in the distal limb; they merge into single veins proximally

The dorsal venous network drains into

Two large superficial veins: the cephalic vein (laterally) and the basilic vein (medially)

The median cubital vein

Connects the cephalic and basilic veins across the anterior cubital fossa; the most common site for venipuncture

Upper limb lymphatics travel toward

The axilla and the axillary lymph nodes

Upper limb lymphatics usually travel alongside

The superficial veins

The axillary lymph nodes are clinically important because

They drain the entire arm AND the thoracic wall including the breast; primary metastatic route in breast cancer

The axilla is the space between

The upper arm and the lateral thoracic wall; the armpit

Contents of the axilla (all embedded in fat)

Axillary artery and branches, axillary vein, axillary lymph nodes and vessels, cords and terminal branches of the brachial plexus

The axillary sheath

A sleeve-like extension of the deep cervical fascia that encloses the axillary vessels and brachial plexus

C5 and C6 form which brachial plexus trunk

The upper trunk

C7 alone forms which brachial plexus trunk

The middle trunk

C8 and T1 form which brachial plexus trunk

The lower trunk

The lateral cord is formed from

Anterior divisions of the upper and middle trunks (C5–C7)

The medial cord is formed from

Anterior divisions of the lower trunk only (C8–T1)

The posterior cord is formed from

Posterior divisions of ALL three trunks (C5–T1)

The 5 terminal nerves of the brachial plexus

Musculocutaneous, median, ulnar, axillary, and radial nerves

Musculocutaneous, median, and ulnar nerves come from

The medial and lateral cords (anterior cords)

Axillary and radial nerves come from

The posterior cord

Musculocutaneous, median, and ulnar nerves together innervate

Anterior muscles of the arm and forearm and ALL intrinsic muscles of the palm

Axillary and radial nerves together innervate

Scapular and deltoid region muscles and ALL posterior muscles of the arm and forearm

The sternoclavicular joint connects

Medial end of clavicle to the manubrium and 1st costal cartilage

The acromioclavicular joint connects

Lateral end of clavicle to the acromion of the scapula

The scapulothoracic joint is

Not a true bony joint; a functional articulation between the serratus anterior and subscapularis muscles

Classification of the glenohumeral joint

Ball-and-socket synovial joint; most mobile but LEAST stable joint in the body

The glenoid labrum

A rim of fibrocartilage that deepens the glenoid cavity and increases stability of the glenohumeral joint

What does the synovial membrane do at the biceps tendon

Forms a tubular sheath around the long head of biceps brachii as it passes through the glenohumeral joint

The SITS rotator cuff muscles

Supraspinatus, Infraspinatus, Teres minor, Subscapularis

Role of the rotator cuff tendons

Reinforce the fibrous capsule of the glenohumeral joint and dynamically compress the humeral head into the glenoid

Anterior arm (brachium) compartment contains (nerves/vessels)

Musculocutaneous nerve; brachial artery and vein

Anterior arm compartment muscles act to

Flex the glenohumeral and elbow joints; supinate the radioulnar joint

Posterior arm compartment contains (nerve)

The radial nerve

Posterior arm compartment muscles act to

Extend the glenohumeral and elbow joints

Which two nerves pass through the arm without innervating arm muscles

The median nerve and ulnar nerve (travel medially en route to the forearm)

The cubital fossa contains

Biceps brachii tendon, brachial a. and v., proximal radial and ulnar vessels, median nerve, and radial nerve

The elbow joint capsule encloses how many synovial joints

Three: humeroulnar, humeroradial, and proximal radioulnar joints

The humeroulnar joint

Articulation between the trochlea of the humerus and the trochlear notch of the ulna; hinge-type

The humeroradial joint

Articulation between the capitulum of the humerus and the head of the radius; hinge-type

Medial support of the elbow

Ulnar (medial) collateral ligament

Lateral support of the elbow

Radial (lateral) collateral ligament

Function of the annular ligament at the elbow

Encircles the neck of the radius to maintain the proximal radioulnar joint during rotation

Movement produced at the radioulnar joints

Rotation of the distal radius around the stationary ulna producing supination and pronation

The interosseous membrane of the forearm

Connects the shafts of the radius and ulna; transmits compressive forces between the two bones

Anterior forearm compartment nerves

Median nerve and ulnar nerve

Anterior forearm compartment muscles perform

Flexion and pronation of the elbow, wrist, and hand

Posterior forearm compartment nerve

Radial nerve (deep branch; posterior interosseous nerve)

Posterior forearm compartment muscles perform

Extension of the elbow, wrist, and hand; supination of the forearm

Why is brachioradialis paradoxical

It lives in the posterior extensor compartment but passes anterior to the elbow joint axis, acting as an elbow FLEXOR innervated by the radial nerve

Contents of the carpal tunnel

Tendons of flexor digitorum superficialis, flexor digitorum profundus, and flexor pollicis longus PLUS the median nerve

Function of the flexor retinaculum

Bridges the carpal bones on the anterior wrist, preventing bowstringing of flexor tendons

Function of the extensor retinaculum

Bridges the carpal bones on the dorsal wrist, preventing bowstringing of extensor tendons

The radiocarpal joint articulates

The distal radius with the scaphoid and lunate of the proximal carpal row