Axial Skeleton

Axial Skeleton Functions

• Movement of limbs

• Protects brain, spinal cord, and vital organs

• Muscle attachment points

• Blood cell production

Components of Axial Skeleton

• Skull (Correct answer for questions)

• Protects the brain

• Vertebral column: support for the body and spinal cord protection

Appendicular Skeleton Overview

• Composed of 126 bones

• Includes:

  • Pectoral girdle (shoulder girdle)

  • Pelvic girdle (hip girdle)

  • Limbs (arms and legs)

• Girdles attach appendages to the axial skeleton

Pectoral Girdle Details

• Composed of the clavicle (collarbone) and scapula (shoulder blade)

• Attached to axial skeleton via acromioclavicular joint

Pelvic Girdle Details

• Composed of three fused bones: ilium, ischium, and pubis

• Functions: provides strength and bears weight

• Tailbone: differentiates male (rigid) and female (flexible)

Upper Limbs

• Humerus (upper arm)

• Forearm: radius (larger) and ulna (smaller)

• Wrist bones: carpals

• Palm bones: metacarpals

• Finger bones: phalanges

Lower Limbs

• Femur (thigh bone)

• Tibia (larger) and fibula (smaller)

• Kneecap: patella (sesamoid bone)

• Ankle bones: tarsals

• Foot bones: metatarsals and phalanges

Joints Classification

• Functional Classifications:

  • Synarthrosis (immovable, e.g., skull sutures)

  • Amphiarthrosis (slightly movable, e.g., vertebrae)

  • Diarthrosis (freely movable, e.g., shoulder)

• Structural Classifications:

  • Fibrous (immovable)

  • Cartilaginous (semi-movable)

  • Synovial (freely movable)

Types of Synovial Joints

• Hinge (e.g., elbow)

• Pivot (rotation)

• Ball and socket (e.g., hip)

• Ellipsoid (e.g., wrist)

• Saddle (e.g., thumb)

• Plane (gliding movements)