appendicular

Pectoral (Shoulder) Girdle

  • Bones:

    • Clavicle

    • Scapula

    • Function: Attach upper limb to the axial skeleton and allow arm mobility.

  • Scapula Markings:

    • Acromion: The top of the shoulder.

    • Coracoid Process: For muscle attachment.

    • Glenoid Cavity: The socket for the humerus.

    • Spine of Scapula: The posterior ridge of the scapula.

    • Supraspinous Fossa: The region above the spine.

    • Infraspinous Fossa: The region below the spine.

    • Medial Border: Edge of the scapula toward the spine.

    • Lateral Border: Edge of the scapula toward the arm.

    • Superior Angle: The top angle of the scapula.

    • Inferior Angle: The bottom angle of the scapula.

  • Joint:

    • Sternoclavicular Joint: The joint formed by the clavicle and sternum.

Upper Limb

  • Bones:

    • Humerus: Arm bone.

    • Radius: Bone on the thumb side of the forearm.

    • Ulna: Bone on the pinky side of the forearm.

    • Carpals: 8 wrist bones.

    • Metacarpals: I-V, bones of the hand.

    • Phalanges: Bones of the fingers.

  • Humerus Markings:

    • Head: Articulates with the scapula.

    • Greater Tubercle: A site for muscle attachment.

    • Lesser Tubercle: A smaller site for muscle attachment.

    • Capitulum: Articulates with the radius.

    • Trochlea: Articulates with the ulna.

    • Coronoid Fossa: Receives the ulna during flexion.

    • Olecranon Fossa: Receives the ulna during extension.

    • Medial Epicondyle: A prominent projection on the medial side.

    • Lateral Epicondyle: A prominent projection on the lateral side.

Ulna Landmarks

  • Olecranon: The tip of the elbow.

  • Coronoid Process: Forms part of the hinge joint.

  • Radial Notch: The site of articulation with the radius.

  • Styloid Process: A distal projection of the ulna.

Radius Landmarks

  • Head: Articulates with the humerus.

  • Radial Tuberosity: A site for muscle attachment.

  • Styloid Process: A projection at the wrist.

Wrist and Hand

  • Carpals (8):

    • Scaphoid

    • Lunate

    • Triquetrum

    • Pisiform

    • Trapezium

    • Trapezoid

    • Capitate

    • Hamate

  • Metacarpals: I-V → consist of base, shaft, and head.

  • Phalanges: Digits I-V → consist of proximal, middle, and distal (note: the thumb lacks a middle phalanx).

Pelvic (Hip) Girdle

  • Hip Bone (Os Coxa): Comprised of Ilium, Ischium, and Pubis.

  • Markings:

    • Acetabulum: The socket for the femur.

    • Iliac Crest: The top ridge of the ilium.

    • ASIS (Anterior Superior Iliac Spine): The front projection of the ilium.

    • PSIS (Posterior Superior Iliac Spine): The back projection of the ilium.

    • Auricular Surface: Articulates with the sacrum.

    • Iliac Fossa: A depression on the ilium.

    • Ischial Tuberosity: Known as the sit bone.

    • Pubic Symphysis: The joint between the pubic bones.

  • False vs True Pelvis:

    • False Pelvis: The upper portion that supports abdominal organs.

    • True Pelvis: The lower portion that surrounds the pelvic cavity; important for childbirth.

Male vs Female Pelvis

  • Female Pelvis:

    • Wider inlet and outlet.

    • Lighter bones.

    • Pubic arch greater than 90°.

  • Male Pelvis:

    • Narrower shape.

    • Heavier bones.

    • Pubic arch less than 90°.

Lower Limb

  • Bones:

    • Femur: The thigh bone.

    • Patella: The kneecap.

    • Tibia: The medial bone of the leg.

    • Fibula: The lateral bone of the leg.

    • Tarsals: Bones of the ankle.

    • Metatarsals: Bones of the foot.

    • Phalanges: Bones of the toes.

  • Femur Markings:

    • Head: Articulates with the acetabulum.

    • Neck: The narrower part below the head.

    • Greater Trochanter: Site for muscle attachment.

    • Lesser Trochanter: Another site for muscle attachment.

    • Medial Condyle: Part of the knee joint.

    • Lateral Condyle: Another part of the knee joint.

    • Medial Epicondyle: A prominent projection.

    • Lateral Epicondyle: Another prominent projection.

    • Intercondylar Fossa: A notch between the condyles.

Patella

  • Base: Top portion.

  • Apex: Bottom point.

  • Articular Facets: Areas that contact the femur during movement.

Tibia

  • Medial Condyle: Part of the knee joint, located on the medial side.

  • Lateral Condyle: Part of the knee joint, located on the lateral side.

  • Tibial Tuberosity: Attachment site for the patellar ligament.

  • Medial Malleolus: The inner ankle projection.

Fibula

  • Head: The proximal end of the fibula.

  • Lateral Malleolus: The outer ankle projection.

Foot Bones

  • Tarsals:

    • Talus

    • Calcaneus

    • Navicular

    • Cuboid

    • 1st-3rd Cuneiform

  • Metatarsals: I-V → consist of base, shaft, and head.

  • Phalanges: Proximal, middle, and distal phalanges.

Foot Arches

  • Longitudinal Arch: Functions for shock absorption.

  • Transverse Arch: Functions for balance and weight distribution.

Homeostasis

  • The skeleton maintains homeostasis by:

    • Storing minerals (such as Ca^{2+}, phosphate).

    • Producing blood cells.

    • Supporting the body.

    • Protecting organs.

Disorders of Appendicular Skeleton

  • Fractures: Breaks in bones.

  • Osteoporosis: Condition characterized by low bone density.

  • Dislocations: Occurs when a bone is out of its joint position.

  • Sprains: Injury to ligaments.

  • Arthritis: Inflammation of joints.