Osteology

Question 1

How many bones does the dog have?

Answer 1

321 bones

Question 2

What are the 5 functions of Bones?

Answer 2

1) Support - body shape and weight
2) Levers - Long bones have more leverage for work
3) Protection - i.e ribcage
4) Calcium and Phosphate reservoir
5) Red Marrow - source of blood cells

Question 3

What are 3 broad ways you can classify bones?

Answer 3

1) Development
2) Location
3) Shape

Question 4

Developmentally there are two classifications for bones…what are they?

Answer 4

1) Endochondral bones: develop from cartilage

 precursors - \*most bones\* - when in doubt guess endo                       

2) Intramembranous bones - develop directly from meenchyme (fascia) - bones of the calvaria (dorsal brain case) and face

Question 5

Location wise there are 3 ways to classify bones, what are they?

Answer 5

1) Axial skeleton - head, vertebral column (including tail), ribs and sternum
2) Appendicular skeleton - bones of limbs, including scapula and os coxae (hip bone)
3) Heterotropic bones - os penis (carnivore and rodent - os cardis in cattle

Question 6

There are 5 bone classifications by Shape…what are they?

Answer 6

1) Long bones -length greater than diameter
2) Short Bones - apporx equiv dimensions
3) Flat bones - scapula, os coxae, skull bones
4) Irregular bones, short and multiple processes
5) Sesamoid bones - small “seed-like” within tendons ex. patella (knee cap)

Question 7

What is bone made of?

Answer 7

Collagen fibers and Hydroxyapatite crystals

Collagen fibers - 1/3 of the bone by weight

Hydroxyapatite crystals - (Ca) 10 (PO4) 6 (OH)2