Chp 5 Muscloskeletal Development and Adaptation Flashcards
Embryobronic development somites change into what????
what do vertebrae develop from????
what happens at 7 weeks GA age
what about eight weeks
somites change from myotomes and into dermatomes
Sclerotomes turn into vertebrae.
7 weeks - will differnate into type 1 and type2 muscle fibers
week 8 - Ach receptors are made
muscle tendont unit comprises of what???
what factors does the muscle unit get affected by
MTU - comprises of cytoskeletal system, endo and exoscarmic tissue, tendon to the bone. endomyosin, perimysium, epimysium)
firing rate of the motor neuron, recuritment patterns, muscle architecture, the angle of pull the lever arm, and changes in the muscle lengt h
What happens to denervated muscles
they atrophy but type 2 show more atrophy than type 1 and this one type can become predominate in a certain area and mess up the muscles predominate muscle pattern
Skeletal muscle growth what bones don’t grow with the endochrondral ossification
Describe bone development very generally
Tell me what weeks the basic structures of a joint are forming.
clavicle, mandible, and skull dont use endochrodral ossification but others use this and these bones go by the intramembranous ossification
Periosteum is first formed then the primary ossifcation center is formed right in the middle of the bone shaft and then the secondary ossfication center is formed in the bones ends from and the medullary cavity is formed where the bone is hollowed out and the epiphyshyeal plate divides end of the bone from the shaft on both ends and then the periosteum froms around the compact bone while the spongy bone froms on the inside of that and forms the trabecular bone.
basic structures of joints are formed 6-8 in gestination period and then the final touches are made during the first couple of years under the froces of the froces of movement and compression
At what week is the head of the femur deep inside the acetabulum???? What happens at birth??
What position is the child in danger if the hip is dislocated????
When is bone development the most rapid
12 weeks however, during birth the head is less covered and the hip is a very unstable joint
single breech position hips flexed knees extended due to the tight pull of the hamstrings
during the prenatal stage
What factors affect bone growth in prenatal stages
what are somethings seen with bony abnormalities
loading a bone long ways does what
what way do shear froces run in the bones
what is flexure drift
external factors like stretch uterine, aminotic fluid, limited space in the fetus, multiple births, nutrition, genetics, mechnical froces
asymetrical head, plevic obliquity, toricollis
icauses a compression froce or tension and normal changes occur like the tibia is rotated 5 degrees and by maturity it has loaded from 18 to 47 degrees of lateral torsion
shear froces run parallel to the epiphyseal plate
flexure drift- is when a bone is bent and the convex side bone is taken from and deposited on the concave side to help straighten out the bone.
and this is seen in the femur and tibia in a normal developmental pattern.
What factors can lead to prenatal deformities
decreased aminotic fluid, limited space in which the fetus can grow, external froces from slightly stretched uterine, and abdominal walls genetic coding, nutrition and the combo of of various mechanical froces.
Femoral torsion is what
what is Antetorsion and what is it at birth vs an adult
what is antetorision and what is it at birth and what is it at adult hood.
Why do babies have an externally rotated posture.
The line between the femoral condyles and the head and neck of the femur and should be 15 degrees. How upward it is. Then antetorsion is how much the head and the neck are rotated “forward” compared to the condyles.
Antetorsion - at 14-16 reduces from a 30-40 to an about an average of a 16
Anteversion and retroversion are are how the femroal head is in line with the actebulum-
At Birth you 40-60 degrees of Anteversion and about ages 8-10 its 15 to 20 degrees and adult its only about 12.
At birth they are externally rotated because they anterversion of 60 and antertorsion at 30
is weightbearing good for strengthening fractures
yes it is and makes bones more strong.
