Chapter 6 Flashcards
Bones of the Head devided into four groupes.
8 which form the cranial vault around the brain (neurocranium), 14 form the skeleton of the face (viscerocranium), 6 auditory ossicles, and the hyoid bone at the base of the toung
Define skull
22 bones forming the neurocranium and viscerocranium are collectively the skull.
Difine calvaria
superior aspect of the skull. made up of parts of four bones (frontal bone, left and right parietal bones, and occipital bone)
Define fontanels
Connective tissue proper membranes between developing calvaria in new borns that has not yet been ossified.
Define foramen magnum
Larg neurovascular passageway which transmit s the spinal cord
Define zygomatic arch
The most obvious landmark on the side of the skull
Which of the neurocranium and viscerocranium contribute to the orbit?
- Neurocranium: frontal bone, ethmoid bone
- Viscerocranium:zygomatic bone, maxilla, lacrimal bone, palatine bone, sphenoid bone
What 3 bones fuse to form the sternum?
The manubrium, sternal body, and xiphoid process
Primary vs secondary centers of ossification
Primary center of ossification: first area in developing bones where the 4 steps of Endochondral ossification take place.
secondary centers of ossification: Ossification at the epphysis of each bone (atleast in long bones)
Both sites are part of Endochondral ossification.
How do long bones continue to grow?
epihyseal cartilages. plates of hyaline cartilage continues to grow, new cartilage is mineralized, reabsorbed, and as it’s reabsorbed cells differentiate into osteoblasts, then they do thier business.
What is the first step of Endo chondral ossification?
Hyaline cartilage model of bone forms from tissues from mesoderm, Model resembles it is to become in shape.
what is the 2nd step of Endochondral ossification?
Cartilage mineralizes to become calcified cartilage.
What is the 3rd step of Endochondral ossification?
The mineralized cartilage is reabsorbed by chondroclasts.
what is the fourth step of Endochondral ossification?
As the cartilage is reabsorbed, cells differentiate into osteoblasts, secrete osteoid, and then bone salts percipitate onto collagenous fibers forming finally the complete definitive bone tissue.
