Anatomy E4: UE

How many segments make up the upper limb? What are they?

4 segments

1. shoulder

2. arm

3. forearm

4. hand

muscles of supination

supinator and biceps brachii

muscles of pronation

pronator teres and pronator quadratus

Shoulder regions

pectoral, scapular, and lateral supraclavicular

Pectoral girdle is made up of

scapulae, clavicles, manubrium

What is the sternoclavicular joint (SC)?

bony articulation between pectoral girdle and axial

what makes up the arm (brachium) component?

humerus

What makes up the forearm (ante brachium) component?

radius, ulna

What makes up the hand (manus) component?

carpals, metacarpals, phalanges

How many regions make up the upper limb?

16 regions

Label: what are regions 1, 2, 3, 4

1: deltoid

2: clavipectoral triangle

3: pectoral

4: scapular

Label: what are regions 5, 6,7, 8

5: axillary

6: anterior arm

7: posterior arm

8: cubital

Label: what are regions 9, 10, 11, 12

9: posterior elbow

10: anterior forearm

11: posterior forearm

12: anterior wrist

Label: what are regions 13, 14, 14, 16

13: posterior wrist

14: palm/palmar

15: dorsum of hand

16: digits (fingers & thumb)

What bones make up the upper limb?

clavicle, scapula, humerus, ulna, radius, carpal bones (8), metacarpal bones (5), phalanges

How many carpal bones are there in the hand?

8 carpals (2 rows of 4)

-make up the wrist

clavicle function:

protects neurovascular bundle

transmits shock/stress from upper limb to axial skeleton

Clavicle features:

sternal end: medial end enlarges where it attaches to sternum (manubrium) (SC joint)

acromial end: laterally articulates to the acromion of the scapula (AC joint)

medial 2/3 is convex anteriorly

Scapula location

overlies posterolateral ribs 2-7

Scapula parts:

spine of scapula, acromion process, sub scapular fossa, coracoid process

Lateral scapula features:

glenoid cavity fossa, supraglenoid tubercle, infraglenoid tubercle

Articulations of shoulder girdle

sternoclavicular joint (SC)

Acromioclavicular join (AC)

Scapulothoracic joint

Glenohumeral (scapulohumeral joint)

What does the clavicle articulate with?

manubrium of sternum and 1st costal cartilage

SC supports what movements?

elevation/depression

protraction/retraction

What is the function of the interclavicular ligament?

strengthens the capsule superiorly

What is the location of the costoclavicular ligament?

between sternal end of clavicle and 1st rib and its costal cartilage

What is the location of the anterior SC ligament?

between clavicle and manubrium

The AC joint supports what movement?

gliding movement

the AC joint capsule is reinforced by what?

coracoclavicular ligament

acromioclavicular ligament

AC separation

shoulder separation: AC & CC ligament torn

-common

Scapulothoracic joint features:

no bony articulation exists between scapula and thoracic cage

What is the glenoid fossa?

part of the glenohumeral joint

-articulates with head of humerus

The glenoid fossa is unstable. what is it reinforced by?

ligaments and muscles

held in place by rotator cuff muscles

inferior part of joint capsule is the weakest area

The ball-and-socket synovial joint of the shoulder supports what types of movement?

flexion/extension

abduction/adduction

medial/lateral rotation

circumduction

ligaments of the glenohumeral joint

superior, middle, and inferior glenohumeral

Coraco-acromial ligament function

prevents superior displacement of humerus

Subacromial bursa

separates acromion from supraspinatus muscle; pain felt mainly during initial stages of abduction and forward flexion

sub deltoid bursa

separates deltoid m. from head humerus

Subcoracoid bursa

located anterior to the subscapularis m. and inferior to the coracoid process

What is the largest upper extremity bone?

humerus

What features does the shaft of the humerus have?

deltoid tuberosity and radial groove

What condyles are on the humerus?

trochlea, capitulum, olecranon fossa, coronoid fossa

What do the capitulum and trochlea articulate with?

cap: articulates with radial

troch: articulates with trochlear notch

What muscles attach to the great tubercles of the humerus?

supraspinatus m, infraspinatus m, teres minor m.

What lies within the bicipital groove?

contains end of long head of biceps brachii

-located between greater and lesser tubercles

During flexion, where does the coronoid process of ulna go?

it is received by the coronoid fossa

Radius location

lateral and shorter of the 2 forearm bones

-shaft enlarges distally

Styloid process

receives most of force from the hand

-part of the radius

Radial styloid process

articular surfaces for scaphoid and lunate bones of wrist

Ulna location

medial and longer of the 2 forearm bones

What does the trochlear notch articulate with?

trochlea of humerus

carpal bones and ulna

ulna does not articulate directly with carpal bones

What is the colles fracture?

complete fracture of distal 2cm of radius

most common forearm fracture

most common fracture in people over >50 yo

What nerves supply the elbow joint?

musculocutaneous, radial, and ulnar nerves

what bursa is located directly on the elbow and is a more common location of bursitis?

subcutaneous olecranon bursa

Carpal bone shape

shape is convex posteriorly, concave anteriorly

Wrist bone pneumonic

So long to pinky, here comes the thumb

scaphoid, lunate, triquetrum, pisiform (proximal; med→lat)

hamate, capitate, trapezoid, trapezium (distal; med→)

How many metacarpal bones are there?

5; 1st metacarpal = thumb = thickest and shortest

Which part of the metacarpals connects to the phalanges?

distal head articulate with proximal phalanges

How many phalanges are in each finger?

each digit has 3 expect the thumb

Distal phalanges

flattened with expanded(tufts) under nail beds

Proximal interphalangeal joints (PIP) location

between proximal and middle phalanges

Distal interphalangeal joints (DIP) location

between middle and distal phalanges

Brachial plexus is made up of what nerves?

C5-T1

ulnar n, radial n, median n, musuclocutaneous n

-innervates entire upper limb

Which portion of the arm does C5 innervate?

shoulder; musculocutaneous

Which portion of the arm does C6 innervate?

elbow; musculocutaneous

Which portion of the arm does C7 innervate?

wrist; radial

Which portion of the arm does C8 and T1 innervate?

hand; ulnar and median

Arteries of the UE

subclavian a., axillary a., brachial a., radial a., ulnar a.

veins of the UE

ulnar, radial, median cubital, brachial axillary, subclavian

venous drainage of UE

axillary v., subclavian v. superior vena cava (SVC)

Shoulder movements

abduction, adduction, flexion, extension, medial rotation, lateral rotation, elevation/depression, protraction/retraction, rotation

What muscles do you use when you raise your arm?

first: supraspinatus m.

second: deltoid m.

third: serratus anterior m.

How many arm muscles are there?

4; 3 flexors, 1 extensor

Movements of forearm:

flexion, extension, supination, pronation

anterior groups = flexors

posterior groups = extensors

Flexion/extension of the forearm is done through…?

through the trochlea

Pronation/supination of the forearm is done through…?

through capitulum of humerus

Which nerves control forearm flexion?

musculocutaneous

-radial and median also involved

Which nerves control forearm extension?

radial

Which nerves control forearm pronation?

median

Which nerves control forearm supination?

musculocutaneous for biceps brachii m.

radial for supinator m.

Superficial veins of the arm

cephalic and basilic veins

Deep veins of the arm

brachial vein ends by merging with basilic vein to form axillary vein

Lymph nodes of UE

epitrochlear nodes, lateral axillary nodes (humeral), central axillary nodes, infraclavicular nodes

nerves of the forearm

median, radial, ulnar

Median n. innervates:

majority of flexors and pronator of forearm

Ulnar n. innervates:

supplies only flexor carpi ulnaris m. and ulnar half of flexor digitorum profudus

-becomes superficial at the wrist, running on the medial side of the ulnar artery

If the Radial n. (deep and superficial branches) is injured, this results in what condition?

Saturday nigh palsy or crutch palsy

-wrist drop

Cubital fossa

triangular shaped area rich in veins, arteries, and nerves

Anatomical Snuff box

tendon of the abductor pollicis longus and extensor pollicis brevis bound it laterally

tendon of extensor pollicis longus bound it medially

Thenar eminence

base of thumb and lateral aspect of hand

hypothenar eminence

medial and smaller portion, proximal to base of fifth finger

What are the bye-bye muscles?

lumbricals 1 and 2

-bc they flex the MCP join and extend the IP joints