The skeleton consists of: • Bones: special connective tissue, hard. • Cartilage: special connective tissue, less hard than bones. • Joints: joint is the location at witch two bones make contact, whereas ligaments are the real site of contact (dense proper connective tissue: collagens.) - Types of joints: fibrous joint, cartilaginous joint, and synovial joint. • Tendons: dense proper connective tissue, connects muscle to bone.

Bony skeleton:

206 bones

Axial skeleton:

80 bones

Skull, auditory ossicles, vertebral

column, thorax (ribs and sternum)

Appendicular skeleton:

126 bones

Upper appendicular:

64 bones

Lower appendicular:

62 bones

a calcified connective tissue that stores calcium and phosphorus.

1. Support and protection. Ex. Skull protects the brain. 2. Serves as a lever, and helps to muscle attachment which is

responsible for body movement. 3. Blood cell formation due to the delicate blood forming bone

marrow within its cavities. 4. Mineral storage (calcium especially).

Classified according to relative amount of solid matrix (Ca\P), number and size of bone marrow cavities: 1. Compact bone (cortical): • Full with: Ca, P. 2. Spongy bone (cancellous) (trabecular): • Full with: bone marrow cavities.

1.Long bones: two ends (epiphysis) and a shaft (diaphysis).

2.Short bones: cube – shaped bones. 3.Flat bones: thin and curved. 4.Irregular bones: their shapes are irregular

and complicated. 5.Sesamoid bones: bones embedded in

tendons.

Shoulder girdle:

4 bones

Clvicle: 2

Scapula: 2

Free - part limb:

60 bones

Humerus: 2

Radius: 2

Ulna: 2

Carpals: 16

Metacarpals: 10

Phalanges: 28

• Spine: prominent plate of bone that separates the suprspinatous from the infraspinatous fossa. • Acromion: flattened lateral portion of the spine of scapula. • Coracoids process: a small hook-like structure on the lateral edge of the superior anterior portion of the scapula. Together with the acromion, serves to stabilize the shoulder joint. It’s palpable. • Glenoid cavity: articulates with the head of humerus. • Suprascapular notch: contains a ligament called suprascapular ligament.

• Muscles and ligaments attachment • Fixation of the shoulder joint • Connection with axial skeleton by clavicle. • Important for movement.

• Long bone: proximal end, shaft, and

distal end.

• Head: covered with hyaline cartilage and makes articulation with glenoid cavity. • Anatomical neck: there’s a tendon that comes through it for the biceps muscle. • Surgical neck: treated by surgery. • Intertubercular groove: divided into medial lip, lateral lip, and floor. • Deltoid tuberosity: muscle attachment for deltoid muscle. • Medial condyle (trochlea) is bigger and there’s a nerve cross behind it called “ulnar nerve.” • Olecranon fossa: articulates with olecranon process of ulna.

- Synovial ball and socket joint between

the head of humerus and the glenoid cavity of scapula. - Supports a wide range of movements provided at the cost of skeletal stability. Joint stability is provided, instead, by rotator cuff muscles which blend with the joint capsule to surround the anterior, posterior, and superior aspects of the shoulder joint. - Humerus dislocation is common. - Treatment: surgery, or Kocher’s method.

• The longer of the two forearm bones • Located medially (pinky side) • The head is at the distal end. • Styloid process is located medially. • Notch called radial notch of ulna. • Other structures: olecranon process, trochlear notch, coronoid process.

• The shorter of the two forearm bones. • Located laterally (thumb side) • The head is at the proximal end. • Styloid process is located laterally. • Notch called ulnar notch of radius. • Other structures: neck, dorsal radial tubercle.

• Carpals: 16 bones (each hand 8). •Metacarpals: 10 bones (each hand 5). • Phalanges: 28 bones (each hand 14).

From lateral to medial: • Proximal row: scaphoid, lunate, triquetrum, pisiform. • Distal row: trapezium, trapezoid, capitate, hamate.

•Numbered from 1 to 5, from lateral to medial. • Base and shaft are concave, head is convex.

Two bones in the thumb (proximal and distal), and three in each finger (proximal, middle, and distal).

• The ulna doesn’t articulate with the carpal bones directly. Instead, there’s a triangular disk between them. • The radius articulates with scaphoid and lunate.

• Between carpals: intercarpal articulations. • Between carpals and metacarpals: carpometacarpal joints. • Between metacarpals and phalanges: metacarpophalangeal joints. • between phalanges: interphalangeal articulations.