Appendicular Skeleton Lab Overview

Appendicular Skeleton Overview

Objectives

  • Differentiate between axial and appendicular skeletons.
  • Understand the anatomy of the appendicular skeleton and identify all bones and their features.
  • Distinguish left from right on paired bones.
  • Know the anatomy of the knee joint and identify structures in pictures/models.

Major Parts of the Appendicular Skeleton

  • Pectoral Girdle
  • Upper Limbs
  • Pelvic Girdle
  • Lower Limbs

Bone Features Definitions

  • Trochanter: Large, rough projection for muscle/tendon attachment, found on the femur.
  • Tuberosity: Large, rounded, rough projection; smaller than a trochanter, also for attachment.
  • Acetabulum: Deep, cup-shaped socket in the hip bone that holds the femur for the hip joint.
  • Patellar Surface: Smooth groove on the anterior side of the distal femur for the patella.
  • Malleolus: Bony bump on each side of the ankle; ends of the tibia and fibula.

Pectoral Girdle

  • Bones: Clavicle and scapula. Supports arm movement & connects upper limbs to the torso.
  • Differentiation: For left/right, position the clavicle with the rounded end inward and flat acromial end outward. Scapula has the spine on the back with the glenoid cavity facing outward.

Upper Limb Anatomy

  • Regions & Bones:
    • Brachial Region (upper arm):
    • Humerus - connects scapula to forearm bones (radius and ulna at elbow).
    • Antebrachial Region (forearm):
    • Radius - located on the thumb side.
    • Ulna - located on the pinky side, forms the elbow.
    • Carpal Region: Contains 8 carpal bones. Mnemonic: "Some Lovers Try Positions That They Can’t Handle" (Scaphoid, Lunate, Triquetrum, Pisiform, Trapezium, Trapezoid, Capitate, Hamate).
    • Manus/Hand: Includes 8 carpals, 5 metacarpals, and 14 phalanges for dexterity.

Pelvic Girdle

  • Bones: Composed of two hip bones (os coxa), made of ilium (top), ischium (lower back), pubis (front).
  • Differentiation: The acetabulum faces laterally; pubic surface points medially & forward; ischium oriented downward/back.

Lower Limb Anatomy

  • Regions & Bones:
    • Patellar Region: Includes Patella which articulates with the femur at the patellar surface, forming the knee joint.
    • Femoral Region (thigh): Only the Femur; longest & strongest bone, articulates with acetabulum (hip joint) & tibia/patella (knee joint).
    • Crural Region (leg): Contains Tibia and Fibula supporting leg movement.
    • Tarsal Region: 7 tarsals form the ankle and rear foot for support.
    • Pedal Region: 7 tarsals, 5 metatarsals, 14 phalanges for movement and balance.

Knee Joint Anatomy

  • Bones: Femur, tibia, and patella (fibula nearby but not part of the joint).
  • Joint Type: Synovial joint classified specifically as a hinge joint allowing flexion/extension with some rotation.
  • Ligaments:
    • Anterior Cruciate Ligament (ACL): Prevents tibia from sliding forward.
    • Posterior Cruciate Ligament (PCL): Prevents tibia from sliding backward.
    • Medial Collateral Ligament (MCL): Provides stability to the inner knee side.
    • Lateral Collateral Ligament (LCL): Provides stability to the outer knee side.
  • Menisci:
    • Medial Meniscus: C-shaped.
    • Lateral Meniscus: O-shaped. Both are fibrocartilage pads that cushion the joint, reduce friction, and stabilize the femur on the tibia.