Development and Growth of the Musculoskeletal System Flashcards
What does sclerotome form?
What does dermomyotome form?
bones
skeletal muscles, nerves and skin
What develops first, the upper or lower limb buds?
Upper limb buds develop 2 days earlier
What is the stage of limb development at the following times?
- 28 days
- 42 days
- 48 days
- 56
- limb buds
- limb and paddle
- digital rays
- end of embryonic period, articulated limbs, growth only
What does the notochord become?
nucleus pulposus of IVD’s
What are 4 spinal anomalies?
spinal bifida
accessory ribs –> throcic outlet syndrome
hemi-vertebrae –> scoliosis
rachischisis
What induces limb mesenchyme?
apical ectodermal ridges
As the limb buds grow outwards, cells in the progress zone proliferate and acquire a positional value.
When the cells leave the progress zone, cartilage can begin to differentiate, and other elements gain their positional information
Describe the development of joints.
Interzonal cells differentiate into fibroblastic tissue in 3 layers
- Cartilage at future articulating surfaces
- Central zone - menisci, enclosed ligaments, vacuolisation forms cavity
- Capsule from sheath surrounding the interzone
What which 3 axes must growth be regulated?
Which molecules are crucial in this?
What does ZPA induce?
proximodistal - FGF-4 and FGF-8
anteroposterior - rentinoic acid and sonic hedgehog
dorsoventral?
ZPA induces mirror impage limb (chicken)
What anchondroplasia a disorder of>
hyaline cartilage
normal cranial base and vault but face is smaller
normal torso, shorter long bones
Not GH related!
What is amelia/meromelia?
lacking one or more limbs
lacking part of a limb
What are the 4 problems of immature bones?
growth plate fracture
greenstick fracture
buckle or torus fracture
plastic deformative
