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An Introduction to the Appendicular Skeleton

An Introduction to the Appendicular Skeletont1lara.weebly.com/uploads/1/6/3/2/1632178/notespectoral_girdlepdf.pdf · An Introduction to the Appendicular Skeleton The Appendicular

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  • An Introduction to the Appendicular


  • The Appendicular

    Skeleton is composed

    of the 126 bones of the

    appendages (limbs)

    and the pectoral and

    pelvic girdles, which

    attach to the axial


    Each limb is composed

    of three segments

    connected by freely

    movable joints.

  • Identify bone markings of each bone. The

    markings will help you to determine

    whether a bone is the right or left member

  • The Pectoral Girdle

  • Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

    The pectoral girdle, also called the shoulder

    girdle consists of two clavicles two scapula.

    The pectoral girdle connects the arms to the

    axial skeleton

    Provides arm movement and shoulder


  • The Clavicles

  • The Clavicles, called collarbones, are long, S-shaped bones.

    It’s medial end attaches to the sternal manubrium (sternal

    end). This articulation is called the sternoclavicular joint. This

    is the only bony attachment between the upper extremity and

    the axial skeleton.

  • The lateral end is flattened and articulates with the scapulae

    (acromial end) to form part of the shoulder. This articulation is

    called the acromioclavicular joint.

  • The clavicle serves as a brace, or strut, to

    hold the arm away from the top of the


  • The Scapulae

  • The Scapulae or shoulder blade are broad, flat

    triangles. They have two important processes: the

    acromion and coracoid process.

    The acromion connects with the clavicle.

  • The beaklike coracoid (corac = crow, raven) process points

    anteriorly over the tip of the shoulder joint and anchors some

    of the upper limb muscles. The scapula has no direct

    attachment to the axial skeleton.

  • The scapula has 3 angles: superior, inferior,

    and lateral and 3 named borders: superior,

    medial, and lateral.

  • Notice the spine of the scapula, located on the


    There are several fossae (shallow depressions) that

    appear on both sides of the scapula and are named

    according to location.

  • The glenoid cavity, a shallow socket

    articulates the humerus head of the arm


  • The Arm

  • The humerus (the

    brachium) consists of the

    only bone in the arm. It is

    involved in the formation

    of 2 major joints: the

    shoulder and the elbow


  • The humerus head fits

    into the shallow glenoid

    cavity. The greater

    (lateral) and lesser

    (medial), turbercles are

    separated by a groove,

    the intertubercular

    sulcus that guides the

    tendon of the bicep

    muscle to the glenoid


  • The posterior

    view of the

    humerus has a


    area, the



    where the

    shoulder deltoid



  • The distal end of the

    humerus are the medial

    trochlea (looking rather

    like a spool), which

    articulates with the ulna.

    The lateral capitulum

    articulates with the radius

    of the forearm.

    The condyles are flanked

    by the medial and lateral


  • Above the trochlea is the coronoid fossa on the

    anterior surface. The posterior surface is the

    olecranon fossa. The depressions allow the ulna to

    flex and extend.

  • The Forearm

  • The Forearm (also called

    the antebrachium)

    consists of two long

    bones: the Ulna (medial)

    and the Radius (lateral).

    In the anatomical

    position the radius is in

    the lateral and the ulna is

    in the medial position.

    They are joined by an

    interosseous membrane.

  • The Radius disk-

    shaped head

    articulates with the

    capitulum of the


    Just below the head is

    the Radial tuberosity

    where the tendon of

    the biceps muscle of

    the arm attaches.

  • The lateral aspect of its

    distal end is the

    expanded styloid process.

    Palpatate the syloid

    process (thumb side),

    move your fingers just

    medially onto the anterior

    wrist. Press firmly and

    then let up slightly on the

    pressure. You should feel

    your radial pulse.

  • The Ulna the medial bone of the forearm. Its proximal end

    bears the anterior coronoid process and the posterior

    olecranon process (the point of the elbow), which are

    separated by the trochlear notch.

  • The Hand

  • The skeleton of the hand includes 3 groups of bones: the

    carpals (wrist bones), metacarpals (bones of the palm), and

    phalanges (bones of the fingers).

  • The carpus (the wrist) is arranged in 2 irregular rows

    of four bones each. The bones are bound by

    ligaments. The 4 proximal bones:

    Scaphoid: Near styloid process, Lunate: Medial to scaphoid,

    Triquetrum: Medial to lunate bone, Pisiform: Anterior to triquetrum

  • The Four Distal Carpal Bones:

    Trapezium: Lateral, Trapezoid: Medial to

    trapezium, Capitate: Largest, Hamate: Medial,


  • The Metacarpal Bones, numbered 1 to 5 from the thumb side of the hand, radiate out from the wrist like spokes to form the palm of the hand.

    They articulate with proximal phalanges.

    Clench your fist and find the knuckles, these are your metacarpophalageal joints.

  • Phalanges, mini long bones of the hands, (14 total finger bones). Like the bones of the palm, the fingers are numbered from 1 to 5, beginning from the thumb side of the hand.

    Each finger has 3 phalanges (proximal, middle, distal), except the thumb (pollex) which has 2 (proximal & distal).