Lecture 2-Osteology Flashcards
How many bones form the skull?
22
What are the two groups of skull bones?
Neurocranium and viscerocranium
How many bones form the neurocranium and what is their function?
8
Encase and protect brain
What is the calvaria?
Skull cap or vault
What do bones of the calvaria begin as and how do they then develop into bones?
Membranes
Intramembranous ossification
What do bones of floor/base begin as and how do they then develop into bones?
Cartilage
Endochondral ossification
How many bones form the viscerocranium?
14 bones
What are the three depressions forming the cranial floor called?
Anterior, middle and posterior cranial fossae
What are the bones of the calvaria?
Outer table (compact bone) Diploic cavity (spongy bone) Inner table (compact bone)
Why is the calvaria tri-laminar?
For protection without extra weight
When does growth at the suture lines stop?
Puberty
What are fontanelles?
Large areas of unossified membranous gaps between flat bones of the calvaria in infants
What do fontanelles allow?
Alteration of skull size and shape and permit growth
When do fontanelles fuse?
Anterior fontanelle - 18 months-2 years and is then called bregma intersection
Posterior fontanelle - 1-3 months and is then called lambda intersection
What is the early fusion of fontanelles called?
Craniosyntosis
