Plastic region

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fracture
Yield point
Plastic region
Stress (force/c.s. area)
Elastic region
Strain (deformation)
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Connective tissues (revisited)

• Extracellular matrix / producing cells High
• ECM
• HOH, Proteins, Carbs.
• Ex. loose fibrous CT, dense CT, Tendon,
  Ligament, Bone, etc.
• Morphology of CT
• Collagen/Elastin ratio
• Arrangement of fibers
• dependent upon forces acting on the material.

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A major components of Loose, fibrous CT B
Molecular structure of the material
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Arrangement of collagen fibers in dense CT A
dense irregular CT (dermis of skin) B layers
of a ligament C cable-like arrangement of a
tendon
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Bone Growthand Joints
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Bone growth and remodeling

• Two (three) types of bone
• Membrane bone bone forming within connective
  tissue (dermal bone)
• Neurocranium (skull), scapula
• Osteoblasts ? osteoid ? trabeculae (small beam)

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Types of bone (continued)

• Cartilage replacement bone
• Endochondral bone bone that forms within
  cartilage
• Perichondral bone forms in CT on surface of
  bone
• Long bones

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Development of the femur in a late embryo or
fetus of a mammal. A original cartilage being
replaced by bone on periphery (perichondral
bone) original cartilage being replaced by bone
within cartilage (endochondral bone) Blue
cartilage Purple calcified cartilage Pink bone
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B enlarged detail of bone formation Blue
cartilage Purple calcified cartilage Pink bone
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Notes on Joints (articulations)

• Structure and function dependent upon
• Degree and direction of movement needed
• Forces acting upon the joint
• Nature of the material at articulation
• C C
• B B
• C B

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Classification based on overall movement and
material

• Synarthroses restricted movement
• Sutures

1. Coronal suture
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Functional synarthroses

• Reinforced

Not synarthroses
nasal
frontal
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• Synchondroses

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• Sympases
• Fibrocartilage
• Some elastin

1.Symphysis mentalis 2.Synchondrosis
sphenooccipitalis3.Synchondrosis
intraoccipitalis anterior4.Fonticulus
posterior5.Synchondrosis intraoccipitalis
posterior
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Diarthroses (synovial joints)

• Lots of movement
• Knee
• Jaw

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Functional Types of Joints Gliding joints
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Cranial and Visceral Skeletons

• Chapter 9

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The cranial skeleton

• Three phylogenetic elements A. Chondrocranium
  ( neurocranium). B. Splanchnocranium (
  visceral skeleton).
• Supports gills (gill arches),
• In gnathostomes
• jaws
• ear
• hyoid apparatus
• C. Dermatocranium. Dermal bones.

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Tetrapod Skull

• Two basic partsA. Braincase (elements touching
  brain). B. Face or Rostrum

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Neurocranium

• Protects brain
• Arises as cartilage (ontogenetically and
  phylogenetically)
• Replaced by bone
• Chondrocranium