1. What bones are formed in the embryo as cartilage? How do they become bone?
    Long bones

    Bone replaces cartilage via endochondral ossification
  2. What bones are formed from membranous sheaths? How do they become bone?
    Flat bones

    Intramembranous ossification
  3. Main cell type of cartilage
  4. True / False:
    Cartilage is a vascularized tissue?
    False! Avascular
  5. What specifically give cartilage its strength yet pliability?
    Glycosaminoglycans (GAG) & Type II Collagen in the ECM
  6. Types of cartilage
    Hyaline cartilage

    Elastic cartilage

  7. Where is Hyaline Cartilage found?
    Articular ends of long bones

    Respiratory tract (trachea)

    Ventral ends of ribs

    Temporary skeleton for endochondral bone development of long bones
  8. What type of cartilage appears glassy and bluish in live tissue?
    Hyaline cartilage
  9. Most abundant cartilage type?
    Hyaline cartilage
  10. Composition of Hyaline Cartilage
    Has a perichondrium (except articular cartilage of long bone)

    • Extracellular Matrix (ECM)
    • - Type II collagen (Type IX / Type XI less abundant)
    • - GAGs & multiadhesive glycoproteins
    • - Proteoglycans (aggrecan molecules)

    Chondroitin sulfate & Keratin sulfate chains (each GAGs) attach to a core protein, which then attach via linker proteins to hyaluronine to make up aggrecan (a proteoglycan)
  11. What is significant about ECM of Hyaline Cartilage? Why?
    Matrix is highly hydrated (60-80% of net weight is intercellular water)

    Much of this water is tightly bound to aggrecan-hyaluronan aggregates (imparts resilience)

    Some of the water is bound loosely (allows diffusion / transfer of metabolites thru ECM)
  12. Function and location of isogenous groups
    Mitotic division of cells in ECM of hyaline cartilage.

    Isogenous groups produce the surrounding ECM material
  13. How does the ECM stain in hyaline cartilage? Why?
    Matrix is basophilic due to sulfated proteoglycans
  14. How does the perichondrium stain in hyaline cartilage? Why?
    Perichondrium is eosinophilic (acidophilic) due to type I collagen
  15. What cell types are found in hyaline cartilage?
    Chondrocytes (ECM)

    Fibroblasts (outer perichondrium)

    Formative chondrocytes (inner perichondrium)
  16. Interstitial vs. Appositional growth in hyaline cartilage
    • Appositional growth occurs in growing cartilage (adjacent to perichondrium)
    • - Differentiation of chondroblasts from the perichondrium into elliptical chondrocytes

    • Interstitial growth occurs deep within cartilage matrix
    • - mitotic division of rounded chondrocytes
  17. Degeneration of cartilage
    Chondrocytes hypertrophy and die -> matrix calcifies

    Normal process of endochondral bone formation (increases w/ age)
  18. Cartilage bone model of the fetus is _________
    Hyaline Cartilage
  19. Location of elastic cartilage
    External ear (auricle & external auditory meatus)

    Eustacian (auditory) tube


    Cartilage of the larynx
  20. Composition of elastic cartilage
    Perichondrium is present

    ECM contains type II collagen and elastic fibers
  21. What stain must be used to differentiate elastic cartilage from hyaline cartilage?
    Orcein / resorcein-fuchsin
  22. Location of fibrocartilage
    Intervertebral discs (annulus fibrosa)

    Pubic symphysis

    Meniscus of the knee

    Insertions of tendons and ligaments on the epiphyseal hyaline cartilage
  23. What type of cartilage can be viewed as a hybrid between dense CT and cartilage?
  24. Composition of fibrocartilage
    No perichondrium

    Numerous type I collagen fibers (in addition to type II)
  25. What is significant about the appearance of fibrocartilage?
    Chondrocytes in lacunae are arranged in long rows

    Type I collagen fibers form parallel bundles in directions of stress
Card Set
Exam 1