Anaphy: Chapter 6 Skeletal System

• Skeletal System


  Composed of bones, cartilage, and ligaments joined tightly together to form a strong, flexible framework for the body
• Cartilage


  • Precursor of most bones in embryonic and childhood development
  • Covers many joint surfaces in the mature skeleton
• Functions of the Skeletal System

  • Support
  • Protection
  • Movement
  • Blood Formation
  • Storage
• Osseous (Bone) Tissue


  A connective tissue with a hard, calcified matrix that exists in two forms: Compact (Dense) Bone and Spongy Bone
• Bone Cells


  • Osteogenic Cells
  • Osteoblasts
  • Osteocytes
  • Osteoclasts
• Bone Matrix


  The stony matter that surrounds the osteocytes and lacunae, composed of organic and inorganic matter
• Spongy (Cancellous) Bone


  • Consists of a porous lattice of slender rods and plates called trabeculae, designed to impart strength without adding too much weight
• Compact (Dense) Bone


  • Forms the hard outer shell of the bone, preventing bone marrow from seeping out and providing attachment surfaces for muscles, tendons, and ligaments
• Gross Anatomy of Bones

  • Long Bones
  • Flat Bones
  • Short and Irregular Bones
• Periosteum


  A fibrous sheath that covers the external part of the bone, providing strong attachment and continuity from muscle to tendon to bone
• Endosteum


  Lines the inner surface of the bone, composed of a thin layer of reticular connective tissue separating the bone from the bone marrow
• Types of Bone Marrow

  • Red Bone Marrow
  • Yellow Bone Marrow
• Ossification


  1. Intramembranous Ossification

  2. Endochondral Ossification
• Steps of Endochondral Ossification


  Simplified
• Bone Growth and Remodeling

  1. Elongation of limb bones

  2. Appositional growth

  3. Bone remodeling
• Classification of Bone Fractures


  • Open Fracture
  • Closed Fracture
  • Complicated Fracture
  • Incomplete Fracture
  • Complete Fracture
  • Comminuted Fracture
  • Impacted Fracture
  • Linear Fracture
  • Transverse Fracture
  • Spiral Fracture
  • Oblique Fracture
  • Dentate Fracture
  • Stellate Fracture
• Calcium Homeostasis


  1. Movement of calcium into and out of bone

  2. Regulation of blood calcium levels
• Anatomical Terms for Features of Bones


  • Body, shaft
  • Head
  • Neck
  • Condyle
  • Facet
  • Crest
  • Process
  • Tubercle
  • Tuberosity
  • Trochanter
  • Epicondyle
  • Foramen
  • Canal/meatus
  • Fissure
  • Sinus
  • Fossa
• Axial Skeleton


  • Skull
  • Hyoid Bone
  • Vertebral Column
  • Rib Cage
• Depression


  A broad/shallow elongated basin
• AXIAL SKELETON


  • Bones of the skull
  • Ribs
  • Vertebrae
• Skull


  • Has 22 bones
  • Divided into 8 braincase bones and 14 facial bones
• Hyoid Bone


  Unpaired u-shaped bone not part of the skull, provides attachment point for neck muscles
• Vertebral Column


  • 7 Cervical Vertebrae
  • 12 Thoracic Vertebrae
  • 5 Lumbar Vertebrae
  • 1 Sacral Bone
  • 1 Coccyx
• Rib Cage


  • Protects vital organs
  • Prevents collapse of the thorax during respiration
  • Consists of thoracic vertebrae, ribs with cartilages, and sternum
• Ribs and Costal Cartilages

  • 12 pairs of ribs
  • True ribs (1-7) attach directly to sternum
  • False ribs (8-12) do not attach directly to sternum
• Sternum


  • Divided into manubrium, body, and xiphoid process
  • Has a jugular notch between clavicles
• APPENDICULAR SKELETON


  • Lower limbs
  • Upper limbs
  • Pectoral girdle
  • Pelvic girdle
• Pectoral Girdle


  • Consists of 2 scapulae and 2 clavicles
  • Scapula has 3 large fossae for muscle attachment
  • Acromion process extends from scapular spine
  • Clavicle articulates with scapula at acromion process
• Upper Limb


  • Arm
  • Forearm
  • Wrist
  • Hand
• Arm


  • Region between shoulder and elbow, contains humerus
• Forearm


  • Has radius and ulna bones
• Wrist


  • 8 carpal bones: Scaphoid, Lunate, Triquetrum, Pisiform, Trapezium, Trapezoid, Capitate, Hamate
• Hand


  • 5 metacarpal bones
  • 5 digits (thumb and fingers) with phalanges
• Pelvic Girdle


  • Right and left hip bones join anteriorly and to sacrum posteriorly
  • Each hip bone formed by 3 fused bones: ilium, ischium, pubis
  • Pelvic inlet formed by pelvic brim and sacral promontory
  • Pelvic outlet bounded by ischial spines, pubic symphysis, and coccyx
• Lower Limb


  • Thigh
  • Leg
  • Ankle
  • Foot
• Thigh


  • Region between hip and knee, contains femur
• Leg


  • Region between knee and ankle, contains tibia and fibula
• Ankle


  • Distal ends of tibia and fibula form a partial socket articulating with foot bones
  • Medial malleolus of tibia and lateral malleolus of fibula are prominences
• Foot


  • 7 tarsal bones: talus, calcaneus, cuboid, navicular, 3 cuneiforms
  • Metatarsal bones
  • Phalanges