top of page
Anatomical Model

Anatomy & Physiology: Week Two

Chapter Eight: The Skeletal System

Introduction to the Skeletal System

The skeletal system is composed of:
  • Bones
  • Joints
  • Cartilage
  • Ligaments
Picture100.jpg

What does It Do?

  • Supports our body weight
  • Supports and protects soft organs
  • With muscles, enables body movement
  • Stores important minerals, including calcium and phosphorus
  • Contains bone marrow, which produces red blood cells
types of bones.png

The Classification of Bones

  • Long 
  • Short
  • Flat
  • Irregular

Two Types of Bones

Compact or hard
  • Osteons (Haversian systems)
Spongy or soft (cancellous)
  • Swiss cheese
  • Bone marrow
Osteon.png

Structure of a Long Bone

​
  • Diaphysis
  • Epiphysis
  • Epiphyseal disc
  • Medullary cavity
  • Periosteum
  • Articular cartilage
long bone.png
arrow.jpg

             Click to learn the
     Structure of a long bone

Two Types of Ossification

Intramembranous ossification
  • Replacement of thin connective tissue membrane with bone.
  • In flat bones.
Endochondral ossification
  • Replacement of fetal cartilage skeleton with bone.
  • In long, irregular, and short bones.
  • Bone marrow
ossification.jpg

Bones: Growing Taller

Occurs at the epiphyseal disc
  •  Osteoblasts invade cartilage in disc.
  • They mature into osteocytes (bone cells) 
Affected by hormones
  • Growth hormone
  • Estrogen
  • Testosterone

Bones: Growing Wider

​
  •  Sculptor (osteoclasts) hollows bone
  • Builder (osteoblasts) deposits bone on outer surface
  • Osteoclastic activity is called resorption. 
resorption.jpg

Bumps and Grooves

  • Condyle: large knob
  • Epicondyle: Enlargement near a condyle
  • Head: Enlarged, rounded end
  • Facet: Small flattened surface
  • Crest: Ridge
  • Spine: Sharp projection
  • Tuberosity: Knoblike projection
  • Trochanter: Large tuberosity only on femur
  • Foramen: Opening, usually passage for nerves, blood vessels, ligaments
  • Fossa: Groove
  • Meatus: Tunnell or tubelike passageway
  • Sinus: Cavity or hollow space
processes1.png
processes2.png

Broken Bones

  • Simple
  • Compound
  • Greenstick
broken bones.jpg

Bones of the Axial Skeleton

  • Skull: Cranium, facial, middle ear bones
  • Hyoid
  • Vertebral column
  • Thoracic cage: Ribs, sternum, thoracic vertebrae
axial skeleton.jpg

Cranial Bones

Cranial bones.jpg

             Click to review the                        cranial bones

Facial Bones

facial bones.jpg

Sinuses

  • Frontal
  • ethmoidal
  • Sphenoidal
  • Maxillary
sinuses.jpg

             Click to review the                        facial bones

Infant Skull and Fontanels

Fontanels are soft spots
  • Anterior and occipital fontanels
  • Not yet converted to bone
  • Covered with fibrous tissue
  • Allow for cranial growth
fontanels.jpg

The Vertebral Column

Functions
  • Support structure for the head and thorax
  • Attachment for the pelvic girdle
  • Encases and protects the spinal cord
  • provides flexibility
Named according to location
​​
vertebral column.jpg

Curvatures

  • Scoliosis: Lateral curve
  • Kyphosis: Hunchback
  • Lordosis: Swayback
curvatures.jpg

Thoracic Cage

Thoracic cage.jpg

Bones of the Appendicular Skeleton

  • Shoulder Girdle: Scapulae, clavicles
  • Upper Limbs: Humerus, radius, ulna, carpals, metacarpals, phalanges
  • Pelvic girdle: Ilium, ischium, pubis
  • Lower Limbs: Femur, patellaa, tibia, fibula, tarsals, metatarsals, phalanges
appendicular.jpg

             Click to review the                        Bones of the skeleton

skeleton.jpg

Types of Joints

  • Immovable
  • Slightly moveable
  • Freely moveable

Structure of Freely Moveable Joints

  • Articular cartilage
  • Joint capsule
  • Synovial membrane
  • Synovial Fluid
  • Cartilage
  • Some joints also have: bursae, ligaments
synovial.jpg

Types of Joint Movement

  • Flexion - extension
  • Abduction - adduction
  • Pronation - supination
  • Inversion - eversion
  • Plantar flexion - dorsiflexion
  • Hyperextension
  • Circumduction
joint movements.jpg

               Click to review the                     Movements of the joints

             Click to Review
                  Week Two

arrow.jpg
ANA week two frog game.png

             Click to Review
                  Week Two
           Vocabulary Words

arrow.jpg
quizlet.png
bottom of page