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:
Appendicular skeleton:
80 bones
126 bones
Skull, auditory
ossicles, vertebral
column, thorax (ribs
and sternum)
Upper
appendicular:
Lower
appendicular:
64 bones
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:
Free - part limb:
4 bones
60 bones
Clvicle: 2
Humerus: 2
Radius: 2
Scapula: 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.