Development of Musculoskeletal System and Skin Flashcards
What sclerotomal structure develops to allow the nerves to reach the nearby myotomes and dermatomes?
Von Ebner’s fissure
What is the only mature remnant of the notochord?
Nucleus pulposus
What is the last region of the vertebrae to ossify?
Spinous process
Regional differences between vertebrae and ribs are influenced by the expression of what family of genes?
Hox genes
Failure of inferior fusion of the sternal bars results to what sternal deformity?
Bifid xiphoid process
The epimere gives rise to what muscle group?
Intrinsic muscles of the back
Failure of muscle development during embryogenesis results in several sets of developmental anomalies. What muscle fails to form in Poland syndrome?
Pectoralis muscle
Prune belly syndrome is a developmental anomaly that presents as a failure to form which muscle?
Abdominal muscles
One of the malformations of the tail segment is fusion of rear limb buds. What is this condition called?
Sirenomelia
Failure of apoptosis on interdigital tissues of the hands and feet results to what type of congenital defect?
Syndactyly
The limb bone arises from which type of mesoderm?
Lateral plate mesoderm
What is the first step in endochondral ossification?
Artery invades the middle of the cartilage
The secondary ossification centers are found in what area of the long bones?
Epiphysis
What condition is caused by a mutation of the FGFR3 protein, which results in early failure of endochondral ossification due to premature closure of the epiphyseal plates?
Achondroplasia
What condition arises when there is excessive growth hormone released after the growth plates have closed?
Acromegaly
With regards to outgrowth of the limb buds, which structure is on the tip of the bud and what signal is produced in it?
The apical epidermal ridge (AER), the signal produced is fibroblast growth factor 8 (FGF8), which interacts with mesenchyme to keep the limb growing. Implanting FGF8 into an embryo could induce the formation of additional limbs
What is the molecular marker that signals for medio-lateral patterning? Where is it localized?
The protein Sonic Hedgehog (Shh)
It is localized in the medial region of the developing limb, the zone of polarizing activity (ZPA)
What congenital anomaly arises due to disruption of limb initiation and presents with normal looking hands or feet but without the intervening long bones?
Phocomelia
What anti nausea medication was previously prescribed to pregnant patients, which resulted in offspring with underdeveloped or absent limbs?
Thalidomide
Which components do skin come from?
Both ectoderm and mesoderm
Where do the epidermis and dermis originate from?
The epidermis is the outermost layer derived from ectoderm that covers the embryo
The dermis is the inner layer derived from mesoderm. The lateral plate mesoderm and dermatome of the somites contribute to the dermis in different parts of the body
The basal later of the epidermis proliferates and creates what layer of cells that protects the growing embryo?
The periderm
What is the vernix caseosa?
The waxy or cheese like substance found coating the skin of newborn human babies. It keeps the embryo safe from amniotic fluid
What is the innermost layer of the mature epidermis?
Stratum germinatum
