#6 External Ear (Elastin Stain)

Where else does elastic cartilage occur in the body? Eustachian tube and epiglottis.


1. What are the mechanisms of cartilage growth? Appositional and interstitial growth

2. What is the distribution of blood vessels in cartilage, and how does this relate to the nutrition of cartilage? Blood vessels are found only in the perichondrium. Nutrition by diffusion through ground substance

#11 Rib, Cross Section. (H & E)

The cementing lines that delimit the Haversian systems may appear refractile or slightly basophilic. What accounts for this basophilia? Proteoglycans.


1. What structures are found within Haversian canals? Capillaries and nerves
2. Is the osseous lamella adjacent to the Haversian canal the youngest or the oldest lamella of a particular osteon? The youngest

Be sure you know how cartilage and bone differ morphologically, functionally, and with respect to blood supply.

#97 Finger, human, 2 mos. (H&E)

What structure in mature bone is created by the zone of resportion? The marrow canal


1. What are the differences between intramembranous ossification and endochondral ossification?
Intramembranous ossification: does not use a cartilage framework, bone develops directly on or within mesenchyme. Bone growth is appositional. Found in irregular bones such as the bones of the skull.
Endochondral ossification: replaces a preexisting cartilage framework. The bone lengthens through interstitial growth and changes diameter through appositional growth. Found in long bones