The Skeletal System

1
The Skeletal System

• Structures and Functions

2
FUNCTIONS

• Support Provides a framework for
  the body
• Support for soft tissues and a point of
  attachment for muscles

3
Protection

• From injury by skeleton
• Ex skull protects brain
• vertebrae protects spinal cord
• Rib cage protects heart lungs
• Pelvic bones protect
  reproductive organs

4
Movement Facilitation

• Bones serve as levers to which muscles are
  attached, when muscles contract movable joints
  acting as fulcrums cause movement

5
Storage

• Calcium Phosphorus essential for many
  homeostatic balances
• Blood Cells red marrow stores and produces
  RBCs, some white blood cells, and platelets
  (hematopoesis)
• Energy yellow marrow stores lipids for chemical
  energy

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Hematopoiesis

• heme meaning blood
• poiesis meaning to make
• Done in the Red marrow.

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Types of Bones

• Long Bones ex humerus
• Short ex carpals
• Flat ex frontal
• Irregular ex vertebrae

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Structure of Long Bones

• Diaphysis bone shaft
• Medullary Canal hollow area inside bone,
  contains marrow
• Epiphysis ends of bone
• Articular Cartilage covers the epiphysis
• Periosteum fibrous covering, except at joints
• Endosteum thin membrane lines the medullary
  canal

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Spongy vs. Compact

• Spongy contains a network of needle like
  threads of bone tissue that is surrounded by
  marrow. This network is called trabeculae
• Compact outer layer, hard and dense, contains
  osteons (Haversian Systems) which are
  concentric circles of hard bone tissue

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Cartilage

• Made up of cells called chondrocytes
• Lacks blood vessels, so nutrients must diffuse
  through the matrix of gel to reach the cells

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Bone Formation Growth

• In utero skeletal tissue is made up of cartilage
  and fibrous material, so
• Babys bones are cartilage until calcification
  occurs,.
• By birth, many of the long bones,skull bones, and
  bones of the hands and feet are calcified.

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Remodeling

• Replacing of cartilage with calcified bone
  matrix.
• Osteoblasts bone forming cells that do the work
  of remodeling.
• Osteoclasts bone resorbing cells.
• Combined action of these 2 cells allows the
  sculpting of bones .

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Divisions of Skeleton

• Axial Skeleton bones of the center or axis of
  the body ex Cranium, Spine, Thoracic bones,
  Hyoid Bone
• There are a total of 80 Axial Skeletal Bones

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Divisions of Skeleton

• Appendicular Bones of the upper and lower
  extremities or appendages
• Ex Humerus, radius, ulna, carpals etc. Femur,
  Tibia, Fibula, tarsals etc.
• There are a total of 126 appendicular bones

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Skull

• Consists of
• Cranium 8 bones
• Face 14 bones
• Ear 6
• Sutures immovable joints in the skull

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Spine

• Vertebral Column series of vertebrae
• 5 sections Cervical, Thoracic, Lumbar, Sacrum,
  Coccyx
• Cervical 7 vertebrae, 1st cervical vertebrae is
  called the atlas, 2nd cervical vertebrae is
  called the axis.
• Thoracic 12 vertebrae
• Lumbar 5 vertebrae
• Sacrum Coccyx 1 of each

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Appendicular Skeleton

• Humerus Radius Ulna
• Carpals Metacarpals Phlanges
• Ilium Ishium Symphysis Pubis
• Femur Patella Tibia
• Fibula Tarsals Metatarsals
• Phlanges

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Conclusion

• Study Skeletal SystemKnow sections of long bones
  and label skeletal bones