Question | Answer |
T-F Ribs develop from sclerotomes | True |
T-F Ribs develop from costal processes which grow out from the mature vertebral mass | False-Grow out from primative vertebral mass |
T-F Ribs develop intersegmentally | True |
T-F Only in the throacic and lower cervical regions do the costal processes become long bar ribs following the body wall | False- Only in the thoracic |
T-F Chondrification center develops at 6 weeks | False- 7 weeks |
T-F Joint plane forms b/t orginal union of costal process and vertebra | True |
T-F Bilateral ossification centers near angle of rib at 8-9 weeks of intrauterine life | False- Single ossification center |
T-F Proximal end of rib remians cartilagenous | False- Distal end remains cart. |
T-F In 15th yr. 2 secondary centers form in the tuberlce and one secondary center in the head | True |
T-F By the 24th year ossification is complete | False- 25th year |
Underdevelopment of a costal process forms what | Rudimentary Rib |
Overdevelopment of a costal process leading to an increased number of ribs | supernumerary rib |
clinically important because it may injure the brachial plexus or subclavian artery | cervical rib |
Splitting of the costal process forms what | Forked or Bifid rib |
T-F sternum does not develop from sclerotomes | True |
T-F A pair of sternal bands develop at 6 weeks; also one presternum and 2 suprasternums | True |
T-F After attachment of ribs sternal bands fuse in caudalcephalo direction | False- fuse in cephalocaudal direction |
UT-F Besides the lower part of the bands the presternum and suprasternums are also incorporated into the manubrium | False- Upper part of the bands |
T-F Sternum becomes cartilagenous during fusion of sternal bands | True |
T-F Clavicals articulate with the suprasternal cartilages which join the manubrium | True |
Fusion of the cartilagenous sternal components completed at; 7 weeks, 8 weeks or 9 weeks | 9 Weeks |
Ossification begins about_____ months of fetal development | 5 |
Segmentation into sternebrae develops secondarily due to the influence of the_____ | Ribs |
Failure of the sternal bands to fuse results in | Cleft sternum |
Hole in the body of sternum due to defect in chondrification | Perforated sternum |
Notched xiphoid process is the result of what | Failure of inferior sternal bands to fuse |
Ossified suprasternal cartilages that failed to attach to manubrium | Suprasternal bones |
T-F Appendicular skeleton develops from unsegmented somatic mesenchyme of lateral plate origin | True |
When do the limb buds of the appendicular skeleton become visible | 5 weeks |
At the apex of limb bud the surface ectoderm is thickened forming the______ | apical ectodermal ridge |
At weeks ____ limbs reach the cartilagenous stage | 6-7 |
Age at which primary centers of ossification appear | Varies depending on the specific bone |
Differentiation is in a______ direction in a limb | proximodistal |
Most epiphyses have fused with diaphysis by the ____ year | 20th |
First of all bones to begin to ossifiy | Clavicle |
Week in which the clavicle begins to ossifiy | week 5 |
Which bone has the last secondary center of ossification to appear and what year | Clavicle, In the 20th year |
What makes the clavicle atypical in its ossification | It has both intramembranous and some endochondral ossification |
Primary ossification center of the scapula forms what...and in what week | Body, spine, and most of the acromion...8th week of intrautrine life |
Secondary centers for _____ appears at one year and fuses at puberty | coracoid process |
where do the primary centers of ossification form for the humerus, radius, and ulna and what week | In the diaphyses, 8th week intrauterine life |
Where do the secondary centers of ossification for the humerus, radius, and ulna form and at what time | In the epiphyses(usally in distal epiphyses first), 1-14 years |
T-F the carpals are all cartilagenous at birth; each forms a primary center of ossification at the same time | False- each forms a primary center at different ages |
What year are all carpals ossified | 15-20 years of age |
Metacarpals and phalanges have single primary ossification centers at_____weeks of fetal development | 8-12 |
Metacarpals have secondary centers of ossification only_____. Phalanges have secondary centers only______. | Distal epiphyses, proximal epiphyses |
Os coxa has three primary centers of ossification where are they and when are they formed | Ilium, Pubis, Ischium, 3-5 months fetal life |
Age in which all three portions of the os coxa are fused | 17 |
Patella is a sesamoid bone which develops within the quadriceps tendon. In what year does it begin to ossify and when is it finished | 4th year completed at puberty |
Permits shoulders to be approximated | Compete or partial absence of the clavicles |
Congential absence of a limb or limbs | Amelia |
Small bone attaches a hand or foot to trunk | meromelia |
Very short limbs | Micromelia |
"Mermaid" deformity | Sirenomelia |
Fusion of one or more fingers or toes | Syndactyly |
Increase in number of fingers or toes | Polydactyly |
Abnormal cleft between the 2nd and 4th metacarpals | Lobster claw |
Sole of foot inverted and plantar flexed | Club foot |
Partial absence of limbs | Hemimelia |
Mesenchyme between developing bones differentiates into | fibrous or cartilagenous tissue |
Synovial joints arise from_____ in the____ month between______ | clefts, 3rd, developing bones |
Ligaments develop from______ in region surrounding the developing joint | Mesenchyme |