Bones of The Forearm

Ulna:Ulna:

-- Medial bone of the forearm

- Articulations:

Humerus & RadiusHumerus & Radius

-Longer than Radius

-wider above than below

32

Right Ulna

1. Olecranon Process (posterior)

2. Trochlear notch

3. Coronoid Process (anterior)

4. Ulnar Tuberosity (inferior to coronoid)

5. Radial notch (lateral and inferior to the

Radius Ulna

trochlear notch, head of radius)

6. Supinator crest: Below the radial notch

7. Head of Ulna (distal end)

8. Styloid Process (posterior)

Anterior Posterior33

34

Bones of The HandBones of The Hand

Carpal bones (8):

Proximal row (4) &

distal row (4)

Metacarpals (5):Metacarpals (5):

Base, shaft & head

Phalanges:

Proximal, middle & distal

Thumb (Exception)

35

Carpals of proximal row:Carpals of proximal row:

1. Scaphoid 2. Lunate

3. Triquetrum 4. Pisiform

36

Carpals of distal row:Carpals of distal row:

1. Trapezium 2. Trapezoid

3. Capitate (large, with rounded head)

4. Hamate

37

Origin and insertion

� Origin: attachment to an immoveable bone (usually proximal)

� Insertion: attachment to a movable bone (usually distal)

� Belly

� Tendon

38

Muscles Connecting the Upper Limb to the

Thorax

Pectoralis major

� Origin: Clavicle, sternum,

and upper six costal

cartilages

Insertion: Lateral lip of � Insertion: Lateral lip of

bicipital groove of humerus

� NS: Medial and lateral

pectoral nerves

� Action: Adducts arm and

rotates it medially; clavicular

fibers also flex arm

39

Muscles Connecting the Upper Limb to the

Thorax

Pectoralis minor

� Origin: 3rd, 4th, and 5th

ribs

� Insertion: Coracoid

process of scapulaprocess of scapula

� NS: Medial pectoral nerve

� Action: Depresses

scapula downward and

forward; if the scapula is

fixed, it elevates the ribs

of origin

40

Muscles Connecting the Upper Limb to the

Thorax

Subclavius

� Origin: 1st costal cartilage

� Insertion: Clavicle

� NS: Nerve to subclavius from upper trunk of brachial plexus

� Action: Depresses the clavicle 41

Muscles Connecting the Upper Limb to the

Thorax

Serratus anterior

� Origin: outer surface of

Upper eight ribs

� Insertion: Medial border

and inferior angle of and inferior angle of

scapula

� NS: Long thoracic nerve

� Action: Pulls the scapula

forward over thoracic wall

assist trapezius to elevate

arm over 180°above

shoulder 42

Muscles Connecting the Scapula to the Humerus

Deltoid

� Origin: Lateral third of

clavicle, acromion,

spine of scapula

� Insertion: Middle of

lateral surface of shaft lateral surface of shaft

of humerus

� NS: Axillary nerve

� Action: Abducts arm;

anterior fibers flex and

medially rotate arm;

posterior fibers extend

and laterally rotate

arm 43

Muscles Connecting the Scapula to the Humerus

Supraspinatus

� Origin: Supraspinous fossa of scapula

� Insertion: Greater tuberosity of humerus

� NS: Suprascapular nerve

� Action: Abducts arm and stabilizes shoulder jointstabilizes shoulder joint

Infraspinatus

� Origin: Infraspinous fossa of scapula

� Insertion: Greater tuberosity of humerus

� NS: Suprascapular nerve

� Action: Laterally rotates arm and stabilizes shoulder joint 44

Muscles Connecting the Scapula to the Humerus

Teres major

� Origin: Lower third of lateral border of scapula

� Insertion: Medial lip of bicipital groove

� NS: Lower subscapular nerve

� Action: Medially rotates and adducts arm and stabilizes shoulder jointshoulder joint

Teres minor

� Origin: Upper two thirds of lateral border of scapula

� Insertion: Greater tuberosity of humerus;

� NS: Axillary nerve

� Action: Laterally rotates arm and stabilizes shoulder joint

45

Muscles Connecting the Upper Limb to the Thorax

Subscapularis

� Origin: Subscapular

fossa

� Insertion: Lesser

tuberosity of humerustuberosity of humerus

� NS: Upper and lower

Subscapular nerves

� Action: Medially rotates

arm and stabilizes

shoulder joint

46

Rotator Cuff Muscles

� The rotator cuff is the name given to the tendons of four muscles

1- Subscapularis

2- Supraspinatus

3- Infraspinatus3- Infraspinatus

4- Teres minor

� Fused to the underlying capsule of the shoulder joint

� Stabilizing the shoulder joint.

� The cuff lies on the anterior, superior, and posterior aspects of the joint. (deficient inferiorly)

47

Axilla� Pyramid-shaped space between

the upper part of the arm and the side of the chest

� Apex: The upper end of the axilla is directed into the root of the neck

- Boundaries: front (clavicle), behind (upper border of the scapula), medially (outer border of the first rib)the first rib)

� Base: The lower end

- Boundaries: front (anterior axillary fold, formed by the lower border of the pectoralis major muscle), behind (posterior axillary fold, formed by the tendon of latissimus dorsi and the teres major muscle), and medially(chest wall)

48

� Walls of the Axilla

1- Anterior wall: Pectoralismajor, subclavius, and pectoralis minor muscles

2- Posterior wall: Subscapularis, latissimusdorsi, and teres major muscles

Axilla

muscles

3- Medial wall: Upper four or five ribs and the intercostal spaces covered by the serratusanterior muscle

4- Lateral wall: Coracobrachialis and biceps muscles in the bicipital groove of the humerus

49

Axilla

� Contents of the Axilla

1- Axillary artery and its branches, which supply blood to the upper limb

2- Axillary vein2- Axillary vein

3- Lymph vessels and lymph nodes

4- Brachial plexus

50

Axillary Artery

� Begins at the lateral border of the 1st rib as a continuation of the subclavian and ends at the lower border of lower border of the teres major muscle, where it continues as the brachial artery

� The pectoralis minor muscle crosses in front of the axillary artery and divides it into three parts

51

First Part of the Axillary Artery

� Extends from the lateral border of the 1st rib to the upper border of the pectoralis minor.

� Relations

- Anteriorly: The pectoralis major and the skin. The cephalic vein skin. The cephalic vein crosses the artery

- Posteriorly: The long thoracic nerve (nerve to the serratus anterior

- Laterally: The three cords of the brachial plexus

- Medially: The axillary vein

� Branches:

highest thoracic artery (runs along the upper border of the pectoralis minor)

52

Second Part of the Axillary Artery

� This lies behind the

pectoralis minor muscle

� Relations

- Anteriorly: The

pectoralis minor, the

pectoralis major and the

skin

- Posteriorly: The - Posteriorly: The

posterior cord of the

brachial plexus, the

subscapularis muscle,

and the shoulder joint

- Laterally: The lateral

cord of the brachial

plexus

- Medially: The medial

cord of the brachial

plexus and the axillary

vein

� Branches:

- The thoracoacromial artery

- The lateral thoracic artery (runs along the lower border

of the pectoralis minor)

53

Third Part of the Axillary Artery

� This extends from the lower

border of the pectoralis minor to

the lower border of the teres

major.

� Relations

- Anteriorly: The pectoralis major

- Posteriorly: The subscapularis,

the latissimus dorsi, the teres

major, the axillary and radial major, the axillary and radial

nerves

- Laterally: The coracobrachialis,

the biceps, and the humerus. The

lateral root of the median and the

musculocutaneous nerves

- Medially: The ulnar nerve, the

axillary vein, and the medial

cutaneous nerve of the arm

� Branches:

- The subscapular artery (runs along the lower

border of the subscapularis muscle)

- The anterior and posterior circumflex humeral

arteries 54

The axillary vein

� Formed at the lower

border of the teres major

muscle by the union of

the venae comitantes of

the brachial artery and

the basilic vein.the basilic vein.

� Runs upward on the

medial side of the axillary

artery and ends at the

lateral border of the 1st

rib by becoming the

subclavian vein.

55

Brachial Plexus

� formed in the

posterior triangle of

the neck by the

union of the

anterior rami of the

5th, 6th, 7th, and 5th, 6th, 7th, and

8th cervical and the

1st thoracic spinal

nerves

� All three cords of

the brachial plexus

lie above and

lateral to the first

part of the axillary

artery56

Branches of the Brachial Plexus� Roots

- Dorsal scapular nerve (C5)

Rhomboid minor, rhomboid major, levator scapulae muscles

- Long thoracic nerve (C5, 6, 7)

Serratus anterior Serratus anterior muscle

� Upper Trunk

- Suprascapular nerve (C5, 6)

Supraspinatus and infraspinatus muscles

- Nerve to subclavius (C5, 6)

Subclavius muscle57

Branches of the Brachial Plexus

� Lateral Cord

- Lateral pectoral nerve (C5, 6, 7)

Pectoralis major muscle

- Musculocutaneous nerve (C5, 6, 7)

Coracobrachialis, Coracobrachialis, biceps brachii, brachialis muscles; supplies skin along lateral border of forearm when it becomes the lateral cutaneous nerve of forearm

� Lateral root of median nerve (C5, 6, 7)

58

Branches of the Brachial Plexus� Posterior Cord

- Upper subscapular nerve

(C5, 6) Subscapularis

muscle

- Thoracodorsal nerve

(C6, 7, 8) Latissimus

dorsi muscle

- Lower subscapular nerve

(C5, 6) Subscapularis

and teres major and teres major

muscles

- Axillary nerve (C5, 6)

Deltoid and teres minor

muscles; upper lateral

cutaneous nerve of arm

supplies skin over lower

half of deltoid muscle

- Radial nerve (C5, 6, 7, 8;

T1)59

Branches of the Brachial Plexus� Medial Cord

- Medial pectoral nerve (C8; T1) Pectoralis major and minor muscles

- Medial cutaneous nerve of arm Skin of medial side of arm

- Medial cutaneous nerve - Medial cutaneous nerve of forearm (C8; T1) Skin of medial side of forearm

- Ulnar nerve (C8; T1)

- Medial root of median nerve

60

Muscles of the Back

Trapezius:

� Origin: Occipital bone, ligamentum nuchae, spine of 7th cervical vertebra, spines of all thoracic vertebrae

� Insertion: Upper fibers into lateral third of clavicle; middle and lower fibers into and lower fibers into acromion and spine of scapula

� NS: Spinal part of accessory nerve

� Action: Upper fibers elevate the scapula; middle fibers pull scapula medially; lower fibers pull medial border of scapula downward 61

Muscles of the Back

Levator scapulae:

� Origin: Transverse processes of 1st four cervical vertebrae

� Insertion: Medial border of scapula

� NS: dorsal Scapular nerve

� Action: Raises medial border of scapulaof scapula

Rhomboid major:

� Origin: Second to 5th thoracic spines

� Insertion: Medial border of scapula

� NS: dorsal Scapular nerve

� Action: Raises medial border of scapula upward and medially

62

Muscles of the Back

Rhomboid minor:

� Origin:Ligamentumnuchae and spines of 7th cervical and 1st thoracic vertebrae

� Insertion: Medial border of scapula

� NS: dorsal Scapular nervenerve

� Action: Raises medial border of scapula upward and medially

63

Muscles of the Back

Latissimus dorsi:

� Origin: Iliac crest, lumbar fascia, spines of lower six thoracic vertebrae, lower three or four ribs, and inferior angle of scapula

� Insertion: Floor of bicipital groove of bicipital groove of humerus

� NS: Thoracodorsal nerve

� Action: Extends, adducts, and medially rotates the arm

64