Fun Trivia : Skeletal System

Structure Sub-topic of: Human Body Quizzes Interesting Questions, Facts and Information There are a total of 10 general entries. Special Topics Bones, Bones and More Bones It's All About Bones Bones of The Human Body! All About Knees Bones Are Our Levers And Pulleys Them Bones, Them Bones Bone Trivia Foot Fetish? Our Detailed Skull and Facial Bones Bones of the Human Body Medical Meanings: Names of Bones

Interesting Questions, Facts, and Information

Skeletal System

What is the main substance (a protein) secreted by the main cells in cartilage that makes up the extra-cellular matrix?

Cartilage and Bone - The Facts


Collagen secreted by chondrocytes. Chondrocytes are matured chondroblasts but the terms are often interchangeable. Fibroblasts are cells found in connective tissue and secrete collagen along with other proteins. Astrocytes are a type of neuroglia cell that support the neurons of the nervous system.



What is endochondral ossification?

Cartilage and Bone - The Facts


Bone growth within an area of hyaline cartilage. Ossification is simply the making of bone. When bones grow without a cartilage model or precursor, they grow by intramembranous ossification. This happens when short bones (e.g. the ones in your wrists and ankles) grow and when any bone thickens laterally (to the side). Endochondral ossification occurs at the primary centre of ossification - the diaphysis (shaft) of long bones. The secondary centre of ossification is at the epiphyses (ends) of the bone.



Cartilage can grow interstitially or appositionally. What is the principle difference between the two processes?

Cartilage and Bone - The Facts


Appositional growth involves growth from the surface of the cartilage only, whereas interstitial growth occurs from inside it. Neither of these processes are confined to a certain region of the body as implied by one of the above answers. Interstitial growth is only involved in the early development of cartilage formation and occurs by mitotic division of pre-existing chondrocytes. Appositional growth is the more important process where the cartilage can grow in girth by cells differentiating from fibroblasts in the perichondrium (a dense layer of connective tissue surrounding areas of cartilage), becoming chondrocytes.



How does cartilage get its nutrients?

Cartilage and Bone - The Facts


Through diffusion of the nutrients into the ground substance surrounding the cells making up the cartilage. Cartilage is completely avascular. There are blood vessels that supply the perichondrium around the cartilage, and nutrients can diffuse from here, or from the synovial fluid found in joint cavities. Articular cartilage (that covers uniting bones) is without a perichondrium and therefore gains oxygen and nutrients purely from diffusion from the synovial fluid.