Upper Appendage Bones

Clavicle

The clavicle, or collarbone, is a long bone that serves as a strut between the shoulder blade and the sternum. It helps stabilize the shoulder.

• Acromial end: The lateral end that articulates with the acromion of the scapula.

• Sternal end: The medial end that articulates with the manubrium of the sternum.

Scapula

The scapula, or shoulder blade, is a flat, triangular bone located on the posterior side of the ribcage. It provides attachment points for muscles and articulates with the humerus and clavicle.

• Acromion process: Extension of the scapular spine; articulates with the clavicle.

• Coracoid process: Hook-like structure for muscle attachment.

• Glenoid fossa (cavity): Shallow depression that articulates with the head of the humerus.

• Infraspinous fossa: Depression below the spine for muscle attachment.

• Spine: Prominent ridge on the posterior surface.

• Superior angle: Uppermost angle of the scapula.

• Inferior angle: Lowermost angle of the scapula.

• Superior border: Upper edge of the scapula.

• Medial border: Edge closest to the vertebral column.

• Lateral border: Edge closest to the arm.

• Supraspinous fossa: Depression above the spine for muscle attachment.

Humerus

The humerus is the long bone of the upper arm, articulating with the scapula at the shoulder and the radius and ulna at the elbow.

• Capitulum: Rounded lateral condyle that articulates with the radius.

• Coronoid fossa: Depression for the coronoid process of the ulna.

• Deltoid tuberosity: Raised area for deltoid muscle attachment.

• Greater tubercle: Large lateral projection for muscle attachment.

• Head: Proximal rounded end that fits into the glenoid cavity.

• Intertubercular groove/sulcus: Groove between the tubercles for tendon passage.

• Lateral epicondyle: Projection on the distal lateral side.

• Lesser tubercle: Smaller anterior projection for muscle attachment.

• Medial epicondyle: Projection on the distal medial side.

• Olecranon fossa: Posterior depression for the olecranon process of the ulna.

• Trochlea: Spool-shaped medial condyle that articulates with the ulna.

Ulna

The ulna is the medial bone of the forearm, forming the elbow joint with the humerus.

• Coronoid process: Anterior projection that fits into the coronoid fossa of the humerus.

• Olecranon process: Prominent posterior projection forming the elbow.

• Radial notch: Articulates with the head of the radius.

• Styloid process: Distal pointed projection.

• Trochlear notch: Large curved area that articulates with the trochlea of the humerus.

Radius

The radius is the lateral bone of the forearm, important for wrist movement.

• Head: Proximal disc-shaped end that articulates with the capitulum of the humerus.

• Radial tuberosity: Bump for biceps muscle attachment.

• Styloid process: Distal pointed projection.

Carpals, Metacarpals, and Phalanges

The wrist and hand consist of multiple small bones that allow for a wide range of motion.

• Carpals: Eight wrist bones: Capitate, Hamate, Lunate, Pisiform, Scaphoid, Trapezium, Trapezoid, Triquetrum.

• Metacarpals: Five bones forming the palm, numbered I-V from thumb to little finger.

• Phalanges: Fourteen finger bones, each finger has proximal, middle, and distal phalanges (thumb has only proximal and distal).

Pelvic Girdle

Os Coxae

The os coxae (hip bone) is formed by the fusion of three bones: ilium, ischium, and pubis. It supports the weight of the upper body and protects pelvic organs.

• Acetabulum: Deep socket for the head of the femur.

• Sex differences of pelvis: Female pelvis is wider and shallower for childbirth.

• Obturator foramen: Large opening for nerves and blood vessels.

Ischium

• Ischial spine: Pointed projection for ligament attachment.

• Ischial tuberosity: Rough area for muscle attachment and weight bearing when sitting.

Ilium

• Anterior inferior iliac spine

• Anterior superior iliac spine

• Posterior superior iliac spine

• Posterior inferior iliac spine

• Greater sciatic notch: Passage for sciatic nerve.

• Iliac crest: Superior border of the ilium.

Lower Appendage Bones

Femur

The femur is the longest and strongest bone in the body, forming the thigh.

• Fovea capitis: Small pit in the head for ligament attachment.

• Greater trochanter: Large lateral projection for muscle attachment.

• Head: Proximal rounded end that fits into the acetabulum.

• Intercondylar notch/fossa: Depression between the condyles.

• Lesser trochanter: Smaller medial projection for muscle attachment.

• Linea aspera: Ridge on the posterior shaft for muscle attachment.

• Medial & Lateral Condyles: Rounded distal ends that articulate with the tibia.

• Medial & Lateral Epicondyles: Projections above the condyles.

• Neck: Narrow region below the head.

Patella

The patella is the kneecap, a sesamoid bone that protects the knee joint.

Tibia

The tibia is the larger, medial bone of the lower leg, bearing most of the body's weight.

• Medial malleolus: Distal projection forming the inner ankle.

• Tibial tuberosity: Rough area for patellar ligament attachment.

Fibula

The fibula is the slender, lateral bone of the lower leg, important for muscle attachment.

• Head: Proximal end.

• Lateral malleolus: Distal projection forming the outer ankle.

Tarsals, Metatarsals, and Phalanges

The ankle and foot consist of multiple bones that provide support and mobility.

• Tarsals: Seven ankle bones: Talus, Calcaneus, Cuboid, Navicular, Medial cuneiform, Intermediate cuneiform, Lateral cuneiform.

• Metatarsals: Five bones forming the arch of the foot, numbered I-V from big toe to little toe.

• Phalanges: Fourteen toe bones, each toe has proximal, middle, and distal phalanges (big toe has only proximal and distal).

Articulations and Joints

Fibrous Joints

Fibrous joints are connected by dense connective tissue and allow little to no movement.

• Gomphoses: Peg-in-socket joints (e.g., teeth in sockets).

• Sutures: Immovable joints between skull bones.

• Syndesmoses: Bones connected by ligaments (e.g., distal tibia and fibula).

Cartilaginous Joints

Cartilaginous joints are connected by cartilage and allow more movement than fibrous joints but less than synovial joints.

• Symphyses: Bones joined by fibrocartilage (e.g., pubic symphysis).

• Synchondroses: Bones joined by hyaline cartilage (e.g., epiphyseal plates).

Synovial Joints

Synovial joints are freely movable joints characterized by a joint cavity filled with synovial fluid.

• Ball and socket: Multiaxial movement (e.g., shoulder, hip).

• Condylar: Biaxial movement (e.g., wrist).

• Hinge: Uniaxial movement (e.g., elbow, knee).

• Saddle: Biaxial movement (e.g., thumb).

• Plane: Gliding movement (e.g., intercarpal joints).

• Pivot: Rotation (e.g., proximal radioulnar joint).

Knee Joint Ligaments

The knee joint is a complex hinge joint stabilized by several important ligaments.

• Anterior Cruciate Ligament (ACL): Prevents anterior displacement of the tibia.

• Lateral (Fibular) Collateral Ligament: Stabilizes the lateral side of the knee.

• Medial (Tibial) Collateral Ligament: Stabilizes the medial side of the knee.

• Posterior Cruciate Ligament (PCL): Prevents posterior displacement of the tibia.

Table: Types of Joints and Examples

Additional info: The notes are organized by bone regions and joint types, suitable for introductory study of the appendicular skeleton and joint classification in Anatomy & Physiology.