Flashcards in Axial and Developmental Osteology Deck (26)
Divide the bones of the head into four groups and list and enumerate the bones in each group.
1. 8 which form the neurocranium (cranial vault around the brain)
2. 14 which form the viscerocranium (the skeleton of the face)
3. 6 auditory ossicles (tiny bones located within the air-filled cavity of the middle ear)
-malleus (in each middle ear)
4. Hyoid bone (embedded in the muscles at the base of the tongue)
Define skull, clavaria, fontanel, foramen magnum, and zygomatic arch.
1. Skull - the 22 bones forming the neurocranium and viscerocranium
2. Zygomatic arch - most obvious landmark on the side of the skull; composed of the temporal bones and zygomatic bones
3. Foramen Magnum - transmits the spinal cord; largest hole in skull
4. Clavaria - superior aspect of the skull; consists of the frontal bone, left and right parietal bones, and occipital bone
5. Fontanels - "soft spots"; there are six fontantels
- anterior fontanel
- posterior fontanel
- anterolateral fontanel
- posterolateral fontanel
State which bones of the neurocranium and which ones of the viscerocranium contribute to the orbit.
1. Frontal bone - superior portion
2. Ethmoid bone - part of medial wall
3. Sphenoid bone - posterior wall
1. Zygomatic bone - inferolateral aspect
2.Maxilla - inferomedial aspect
3. Lacrimal bone - part of medial wall
4. Palatine bone - part of inferior aspect
List the three bones that fuse to form the sternum.
3. xiphoid process
1. a hyaline cartilage model of the bone forms from tissues derived from the mesoderm. this model resembles the bone it is to become in shape
2. the cartilage mineralizes to become calcified cartilage (only time cartalage has mineral in it)
3. the mineralized cartilage is reabsorbed by chondroclasts
4. as the cartilage is reabsorbed, cells differentiate into osteoblasts, secrete osteoid, and then bone salts (minerals) precipitate onto the collagenous fibers to complete the formations of definitive bone tissue (laying down of bone tissue)
What does endochondral ossification contribute to skeletal development?
it is the mechanism by which the majority of bones in the body initially develop (how we get linear growth in bone)
fibroblasts within c.t. proper membranes simply undergo metaplasia and differentiate into osteoblasts. these osteoblasts then form osteoid to complete the process.
What does intramembranous ossification contribute to skeletal development?
it is involved in the original formation of some flat bones of the body and also is the major mechanism by which most bones grow diametrically
Primary centers of ossification
first area in a developing bone where the 4 steps of endochondral ossification are completed (near the center of the bone)
Secondary centers of ossification
days or weeks later, other areas in the same bone will complete the same four steps. these areas are known as secondary centers of ossification. (in each epiphysis)
Explain how the medullary cavity gets larger in a growing long bone.
State how the inferior nasal conchae differ from the superior and middle nasal conchae.
The superior and middle nasal conchae are parts of the ethmoid bone. The inferior nasal concha is a separate bone. Note that both left and right maxillae and both palatine bones contribute to the bony palate.
Be able to sketch a typical vertebra. What are the parts common to each?
1 - vertebral foramen
1 - spinous process
2 - superior articular process
2 - transverse process
What is the human vertebral formula? Be able to sketch a curved line representing the vertebral column in lateral perspective and label the cervical, thoracic, lumbar, and pelvic curvatures. Note which two are concave and which two are convex anteriorly.
What ribs are true ribs?
What ribs are false ribs?
What ribs are floating ribs?
What do most typical ribs contain?
head, body, neck, tubercle, angle, and costal groove
What ribs lack a tubercle?
How many intercostal spaces are in the ribs?
Indicate the meaning of the following terms in describing fractures: open, closed, transverse, longitudinal, oblique, epiphyseal, diaphyseal, metaphyseal, physeal, greenstick, displaced, overriding, comminuted.
Skin penetration: open (does penetrate), closed (doesn't penetrate)
Orientation of fracture line (the way the fracture is going): transverse, longitudinal, oblique
Part of bone involved: epiphyseal, diaphyseal, metaphyseal and physeal (in young bones)
Degree of break: green stick (incomplete separation of fragments)
Position of fracture fragments relative to eachother: displaced, overriding
Comminuted: the bone has been broken into a number of pieces
refers to a fracture that takes an exceptionally long time to heal
some fractures never heal and form false joints
measurements of the diameters of the pelvis
List the paired and unpaired bones in the neurocranium.
- parietal bones
- temporal bones
- frontal bone *
- sphenoid bone * (touches more surfaces than any other bone)
- ethmoid bone *
- occipital bone
(* means part of orbit)