Plastic region Stress (force/c.s. area) Strain (deformation) Elastic region Yield point fracture.
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Transcript of Plastic region Stress (force/c.s. area) Strain (deformation) Elastic region Yield point fracture.
Plastic region
Str
ess
(for
ce/c
.s.
area
)
Strain(deformation)
Ela
stic
regi
on
Yield point fracture
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.
A – major components of Loose, fibrous CTB – Molecular structure of the material
Arrangement of collagen fibers in dense CTA – dense irregular CT (dermis of skin)B – layers of a ligamentC – cable-like arrangement of a tendon
Bone Growthand Joints
Bone growth and remodeling
• Two (three) types of bone:
1. Membrane bone – bone forming within connective tissue (=dermal bone)
– Neurocranium (skull), scapula
Osteoblasts osteoid trabeculae (small beam)
Types of bone (continued)
2. Cartilage replacement bone
1. Endochondral bone – bone that forms within cartilage
2. Perichondral bone – forms in CT on surface of bone
– Long bones
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 = cartilagePurple = calcified cartilagePink = bone
B – enlarged detail of bone formation
Blue = cartilagePurple = calcified cartilagePink = bone
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
Classification based on overall movement and material
• Synarthroses – restricted movement– Sutures
Sutural ligamentPeriosteum
Dermal bone Dermal bone 1. Coronal suture
Functional synarthroses
• Reinforced
frontal nasal
Not synarthroses
• Synchondroses
• Sympases– Fibrocartilage– Some elastin
1.Symphysis mentalis
2.Synchondrosis sphenooccipitalis3.Synchondrosis intraoccipitalis anterior4.Fonticulus posterior5.Synchondrosis intraoccipitalis posterior
Diarthroses (synovial joints)
• Lots of movement– Knee– Jaw
Functional Types of Joints
Gliding joints
Cranial and Visceral Skeletons
Chapter 9
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.
Tetrapod Skull
• Two basic partsA. Braincase (elements touching brain). B. Face or Rostrum
Neurocranium
• Protects brain
• Arises as cartilage (ontogenetically and phylogenetically)
• Replaced by bone
• Chondrocranium