Reiter 2 Flashcards
Cartilage type determined by composition of
_______ and ______.
- matrix components
- fiber type
Cartilage is ______ (nutrients and waste via diffusion)
avascular
(in prichondrium) synthesize ECM
Chondroblasts
(in lacunae) synthesize and maintain ECM
Chondrocytes
glycoaminoglycans (polysaccharides) and proteoglycans (glycosylated proteins)
Extracellualar matrix
Collagen and elastic describe types of _____.
Fibers
- Most common
- Articular surfaces of joints, trachea and bronchi, end of ribs and epiphyses of long bones
- forms supporting structure for nose
Hyaline cartilage
several chondrocytes in one lacuna
Isogenous nests (IS)
- Least common
- External ear (auricle), external auditory canal, eustachian tube, epiglottis, cuneiform cartilage of larynx
- Abundant elastic fibers (requires special stain)
- Strong and highly flexible
Elastic cartilage
- Combination of hyaline cartilage and dense connective tissue; lacks typical perichondrium
- Intervertebral discs and pubic symphysis
Fibrocartilage
All cartilage growth occurs as a result of the synthesis of matrix by chondroblasts and chondrocytes. Chondroblasts cause _______. Chondrocytes cause _______.
- appositional growth
- interstitial growth
Varieties of bones
- Long bone (humerus)
- Short bone (trapezoid)
- Flat bone (sternum)
- Irregular bone (vertebra)
- Sesamoid bone (patella)
All the bones of the face and skull are
______.
flat bones
Flat bones, short bones, irregular bones
and sesamoid bones use the same process
of formation, called _______; long bones form by _______.
- intramembranous formation
- endochondral formation
Haversian system (basic unit of compact bone)
Osteon
Calcified extracellular material
Bone matrix
Three cell types
- Osteoblasts (osteoid formation)
- Osteocytes (bone maintenance)
- Osteoclasts (bone destruction)
Osteoblasts locate
in _______.
periosteum/endosteum
Osteocytes survive
in ______; communicate
via ______.
- Lacunae
- canaliculi
______ is always between layers of dense bone and
never on the surface of bone
Spongy or cancellous bone
Spongy bone made up of _______; space between these is occupied by bone marrow.
spicules (trabeculae)
Bone is _____, unlike cartilage.
vascularized
Central canal = _______; perforating canal = _______
- Haversian canal
- Volkmann’s canal
from osteoprogenitor cells (form osteoid & collagen)
Osteoblasts
from osteoblasts
Osteocytes
from monocytic cells
Osteoclasts
______ secrete osteoid which undergoes calcification (mineralization)
Osteoblasts
dissolve bone
Osteoclasts
Osteoblasts and osteoclasts located in __________.
periosteum and endosteum
_______ lies between osteoblasts and bone matrix (calcified)
Osteoid (uncalcified)
maintain boney matrix; death is followed by matrix resorption
Osteocytes
______ have relatively little RER and small Golgi apparatus.
Osteocytes
Space between ruffled border and bone is acidified by ______ in osteoclast cell membrane along with release of ______ leading to dissolution of bone
- proton pump
- hydrolytic enzymes
- _______ (with blood vessels)
- _______ (connects Haversian canals)
- _______ (in lacunae)
- _______ (projections from lacunae)
- Haversian canals
- Volkman’s canals
- Osteocytes
- Canaliculi
_______ cover bone surfaces. In epiphyses of long bone, most bone is of ____ variety.
- Periosteum or endosteum
- spongy
________ are morphologically identical. Spicules (trabeculae)
of spongy bone have _____.
- Periosteum and endosteum
- endosteum
- Cartilage model of bone forms first
- At specific periods during embryogenesis, this cartilage is replaced by true bone
- Most bones
- Three ossification centers
Endochondral ossification
- Direct ossification of mesenchymal cells without an intermediate cartilaginous state
- Superficial bones of face and skull
- One or more ossification centers
Intramembranous bone formation
______, (also known as fibrous bone) which is characterized by a haphazard organization of collagen fibers and is mechanically weak. ______, which has a regular parallel alignment of collagen into sheets (“lamellae”) and is mechanically strong.
- Woven bone
- Lamellar bone
_______ is non-lamellar bone; first bone formed and is usually replaced by lamellar bone
Woven bone
The ______ calcifies but is dissolved; it is replaced by bone.
cartilage
When ______ (growth plate) closes, vertical growth is complete (around age 20)
epiphyseal plate
Cartilage covering articular surface is ______.
hyaline cartilage
primary ossification center is in _______; secondary
ossification centers in ______
- Diaphysis
- Epiphysis
Zones of growth
- Zone of resting cartilage
- Zone of proliferating cartilage
- Zone of hypertrophic cartilage
- Zone of calcified cartilage
Zones of growth:
Anchors growth plate to bone
Zone of resting cartilage
Zones of growth:
Rapid cell division (stacked coins)
Zone of proliferating cartilage
Zones of growth:
Cells enlarged and remain in columns
Zone of hypertrophic cartilage
Zones of growth:
- Thin zone, cells mostly dead since matrix calcified
- Osteoclasts removing matrix
- Osteoblasts & capillaries move in to create bone over calcified cartilage
Zone of calcified cartilage
Intramembranous Ossification produces _____ of skull and clavicle, including _____ and _____.
- Flat bones
- Maxilla and mandible
Spongy bone of flat bones called _____.
diploe
Eventually ______ forms over spongy bone.
compact bone
The alveolar process is
continually being ______ like all other bones.
remodeled
Alveolar process is composed of ________.
both compact and spongy bone
The mandible articulates with only one bone, the ______, at the condyle which is covered by _______.
- temporal bone
- hyaline cartilage
The articular disc is composed of _________.
dense fibrous connective tissue (collagen and fibroblasts)
