The Skeletal System

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Skeletal System
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Functions of the Skeletal System

• Support- framework that supports body and gives
  it shape
• Protection- for delicate organs, heart, lungs,
  brain, any internal organs
• Movement- bones act as levers for muscles
• Mineral storage- calcium phosphate
• Blood cell formation- hematopoiesis

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Skeletal Organization

• There are 206 bones in the adult body and they
  fall into 2 Categories
• 1. Axial Skeleton
• 2. Appendicular Skeleton

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Axial Skeleton

• Consists of the bone and cartilage that supports
  and protects the head, neck and trunk
• Skull
• Vertebral column
• Thoracic cage

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Axial Skeleton
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Bones of the axial skeleton
The skull bones
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Sinal Cavities
Frontal Sinus
Ethmoid Sinus
Sphenoid Sinus
Maxillary Sinus

• Warm and moisten air
• Lighten the skull
• Enhance voice resonance

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Axial Skeleton
The Vertebral Column

• Cervical Vertebrae (7)
• Thoracic Vertebrae (12)
• Lumbar Vertebrae (5)
• Sacrum
• Coccyx

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Axial Skeleton
The Thoracic Cage
Sternum True Ribs (7) False Ribs (3) Floating
Ribs (2)
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Axial Skeleton
Sacrum Coccyx
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Appendicular Skeleton

• Includes
• 1. Pectoral Girdle
• 2. Upper Limbs
• 3. Pelvic Girdle
• 4. Lower Limbs

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Appendicular Skeleton
Bones of the Pectoral Girdle
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Appendicular Skeleton
Bones of the Upper Limbs
Humerus
Ulna
Radius
8 Carpals
5 Metacarpals
14 Phalanges
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Appendicular Skeleton
Bones of the Pelvic Girdle
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Appendicular Skeleton
The Lower Limbs (Legs)

Femur
Patella
Tibia
Fibula
7 Tarsals
5 Metatarsals
14 Phalanges
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Types of Bones

• Long Bones- metacarples, metatarsals, phelangies,
  humerus, ulna, radius, tibia, fibula
• Short Bones- carpals, tarsals
• Flat Bones- rib, scapula, skull, sternum
• Irregular Bones- vertebrae, facial bones
• Sesamoid- patella

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Bone Classification
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What type of bones do you think the following
are?

1. Ribs
2. Phalanges
3. Pelvic bone
4. Skull bones
5. Ulna/ Radius
6. Nasal bone
7. Mandible

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Anatomy of a Long Bone

• Bones are organs which means they are composed of
  many types of tissues
• Fibrous connective tissue.
• Cartilage.
• Vascular tissue.
• Lymphatic tissue.
• Adipose tissue.
• Nervous tissue.

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Bone cells that aid in remodeling
Builds new bone
Osteoblast
Mature bone cell
Osteocyte
Osteoclast
Eats bone
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Anatomy of a Long Bone

• Epiphysis The end of each long bone
• Diaphysis The shaft of the bone
• Hyaline Cartilage on the outer surface of the
  epiphysis to assist growth
• Periosteum Completely encloses or wraps around
  the bone (very tough)
• Compact bone Very thick with no gaps around the
  diaphysis
• Spongy bone numerous branching plates and spaces
  in the epiphysis.
• Marrow Red or yellow in the center of bones.

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Anatomy of a Long Bone
spongy bone
Proximal epiphysis
compact bone
Endosteum
diaphysis
epiphyseal line
yellow marrow
Sharpeys fibers
Distal epiphysis
periosteum
hyaline cartilage
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STOP!!

1. Label the human skeleton worksheet
2. You have 10 minutes to quiz each other on the
   skeleton.
3. With a partner you will then construct out of
   toothpicks and other materials the skeleton.

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Bone Formation

• Most bones develop from masses of hyaline
  cartilage shaped like future bones.

This occurs while still in the uterus as a fetus-
usually the first two months.
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Bone Formation

1. The cartilage begins to break down and disappear
   first in the diaphysis. At the same time the
   periosteum begins to form, the cartilage
   calcifies and blood vessels begin.

periosteum
cartilage
calcified cartilage
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Bone Formation

1. Osteoblasts (bone forming cells) from the
   periosteum begin to develop compact bone around
   the diaphysis. The epiphysis cartilage continues
   to grow and calcify.

Compact bone
This is called the primary ossification center-
just before birth
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Bone Formation

1. The secondary ossification center begins to form
   spongy bone in the epiphysis but is not complete.
   The medullary cavity forms which will later house
   the marrow. The diaphysis elongates.

Medullary cavity
Secondary ossification (Spongy bone)
After birth and into childhood
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Bone Formation

1. The diaphysis elongates further. Spongy bone
   forms and compact bone thickens until length and
   structure is complete. The epiphyseal plates
   (growth plate) tell the bone when to stop
   growing.

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Bone Formation

1. Adult bone everything is fully grown! Cartilage
   is only left at the ends of the epiphysis. Marrow
   is now fully formed also

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Endochondral Ossification
Fetus 1st 2 months
2o ossification center
bone
cartilage
calcified cartilage
Just before birth
epiphyseal line
epiphyseal plate
Adult
Childhood
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Use the cut outs to create the steps of bone
formation.
STOP!!

1. You may create a book, foldable, etc.
2. Place each step in the correct order.
3. Label all the appropriate parts in each step.
4. Give a brief description in your own words about
   what is happening in each step.

Use page 130-131 for more help HW project
Children's story to illustrate
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Repair of bone fractures

• Types of bone breaks
• Simple- skin is not pierced (most breaks)
• Compound- skin is pierced
• Complete- bone is broken in half
• Partial- broken lengthwise but not two parts
• Comminuted- broken into several pieces
• Spiral- twisted

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What kind of fracture is this?
Its kind of tough to tell, but this is a _ _ _ _
_ _ fracture.
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Repair of bone fractures
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Bone Repair

• Electrical stimulation of the fracture site
• Increases speed and completeness of healing
• The e- stimulation inhibits PTH and slow
  osteoclasts down from reabsorbing bone
• 2. Ultrasound treatment
• Daily treatments reduce healing time of broken
  bones by 25-35
• 3. Free vascular fibular graft technique
• Transplant fibula in arm
• Gives good blood supply not available in other
  treatments
• 4. Bone substitutes
• Crushed bone from cadaver- but risk of HIV and
  hepatitis
• Sea bone- coral
• Artificial bone- ceramic

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STOP!!

• Discuss these questions with a partner
• What type of bones break the easiest? Why?
• What type of bones do not break easily, why?
• Why are blood vessels important in bones and in
  repairing them?

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Bone strength lab
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Bones and movement

• Bones and muscles interact to cause movements
• Joints are the junction between bones that allow
  movement.
• Three types of joints
• Fibrous joints
• Cartilaginous joints
• Synovial joints

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Immovable Joints (formed by a thin layer of dense
connective tissue)
Fibrous Joints
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Slightly Movable Joint (Hyaline and
fibrocartilage found in-between vertebrae, end of
long bones and between ribs and sternum
Cartilagenous Joints
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Synovial Joints
Freely moveable (includes most joints contain
ligaments, tendons and synovial fluid for smooth
movement
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Knee Joint (Synovial)
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Bones and movement

• Types of freely movable joints
• Saddle carpal and metacarpal bones of thumb
• Ball and socket shoulder and hip joints
• Pivot- rotation only proximal end of radius and
  ulna
• Hinge- up and own movement in one plane knee and
  elbow
• Gliding- sliding and twisting wrist and ankle
• Condyloid- movement in metacarpals and phalanges

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Gliding
Hinge
Pivot
Condyloid
Saddle
Ball and socket
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Diseases of the Skeletal System

• Osteoporosis- bone reabsorption outpaces bone
  deposit bones become lighter and fracture easier
• Factors
• age, gender (more in women)
• hormone decrease
• insufficient exercise (or too much)
• diet poor in Ca , protein, or vitamin D
• smoking

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Osteoporosis
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Diseases of the Skeletal System
Rickets- vitamin D deficiency Osteomalacia- soft
bones, inadequate mineralization in bones, lack
of vitamin D Pagets Disease- spotty weakening in
the bones, breaks down old bone faster than it
rebuilds new bone. Common in old age. Rheumatoid
arthritis- autoimmune reaction effecting the
joints surrounding bones and movement.
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Case study and research
Finish children story
Book work and practice labeling and worksheets
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