Deck 9: Development of the Musculoskeletal System

Question 1

As the limb myogenic precursors migrate into the limb,they are bipotential; that is,they are not yet committed to the myogenic lineage and can give rise to another cell lineage.What is this other cell lineage?

A) Schwann cells
B) Smooth muscle cells
C) Chondrocytes
D) Osteoblasts
E) Osteoclasts
F) Endothelial cells

Answer 1

F

Question 2

During endochondral bone development,the hypertrophic zone of the cartilaginous elements becomes vascularized.Which growth factor is essential for vascularization?

A) Ihh
B) Vegf
C) Wnt
D) Bmp
E) Fgf

Answer 2

B

Question 3

In humans,there are a spectrum of syndromes,including spondylocostal dysostosis and Klippel-Feil anomaly,that are characterized by vertebral and rib abnormalities.Genetic mapping studies have identified mutations in several genes that affect one growth factor signaling pathway.Which is the pathway affected?

A) FGF
B) BMP
C) WNT
D) Retinoic acid
E) NOTCH

Answer 3

E

Question 4

The vertebrae are patterned by the Hox complex of transcription factors,which are expressed in nested domains along the cranial-caudal axis.How would gain of Hox function be expected to affect the developing vertebrae?

A) Cranialize them.
B) Caudalize them.

Question 5

Neural crest cells and motor axons can only migrate through/over one-half of the somite,and this migration is controlled by inhibitory and permissive interactions through factors expressed by the somite and neural crest cells/motor axons.In which half of the somite do neural crest cells/motor axons migrate through?

A) Lateral
B) Medial
C) Caudal
D) Cranial
E) Dorsal
F) Ventral

Question 6

The skeletal structures of the face develop from which tissue?

A) Neural crest cells
B) Mesoderm
C) Neuroepithelium
D) Endoderm

Question 7

Researchers have identified transcription factors that specify different cell lineages.Which transcription factor is essential for formation of chondrocytes?

A) Runx2
B) Myf5
C) MyoD
D) Sox9
E) Pax7

Question 8

Jansen-type metaphyseal chondrodysplasia is caused by mutations in which gene?

A) IHH
B) SOX9
C) PTHRP RECEPTOR
D) SOX6
E) SOX5
F) PTHRP

Question 9

Duchenne muscular dystrophy,a debilitating X-linked muscular disease,is due to mutations in which gene?

A) PABPN1, Polyadenylate-binding protein, nuclear 1
B) Dystrophin
C) MYOR
D) MYOD
E) MYOSIN

Question 10

The vertebrae are patterned by the Hox complex of transcription factors,which are expressed in nested domains along the cranial-caudal axis.Hox gene expression is regulated by retinoic acid. How would gain of retinoic acid function be expected to affect the developing vertebrae?

A) Cranialize them.
B) Caudalize them.

Question 11

The tendons of the limb arise from which structure?

A) Lateral plate mesoderm
B) Neural crest cells
C) Myotome
D) Dermatome
E) Sclerotome

Question 12

Butterfly vertebrae are characteristic of which syndrome?

A) Alagille syndrome
B) Spondylocostal dysostosis
C) Klippel-Feil anomaly
D) VATER/VACTERL

Question 13

During the process of endochondral bone differentiation,chondrocytes differentiate to ultimately form the hypertrophic chondrocytes.Each stage of chondrocyte differentiation is characterized by the expression of distinct matrix molecules.Which matrix molecule defines and is characteristic of the hypertrophic chondrocyte?

A) Aggrecan
B) Collagen Type X
C) Collagen Type II
D) Hyaluronan
E) Collagen Type I

Question 14

The dermis of the ventral body wall arises from which structure?

A) Dermatome
B) Neural crest cells
C) Somatopleuric lateral plate mesoderm
D) Splanchnopleuric lateral plate mesoderm
E) Notochord

Question 15

Belgian Blue and Piedmontese cattle have enlarged muscles.Which gene is mutated in these breeds of cattle? A mutation in this gene has also been found in a human.

A) Frek
B) Scleraxis
C) Myostatin
D) MyoD
E) Pax7

Question 16

A child is diagnosed with mutations in the gene encoding the growth factor GDF5.Which region of the body would show developmental abnormalities?

A) Cranial vault
B) Vertebrae
C) Ribs
D) Limbs
E) Face

Question 17

Genetic inactivation of MyoR and Capsulin in mice affects the development of which structures?

A) All striated musculature
B) Limb musculature
C) Epaxial musculature
D) Hypaxial musculature
E) Jaw musculature

Question 18

When Runx2 (or Cbfa1) is genetically inactivated in mice,which cell lineage does not form?

A) Striated muscles
B) Chondrocytes
C) Osteoblasts
D) Osteoclasts

Question 19

Researchers have recently identified a new compartment within the somite,which contains the tendon progenitors.Which transcription factor is expressed in this "tendon" compartment?

A) Scleraxis
B) Pax3
C) Pax7
D) Pax1
E) Tbx18

Question 20

The nucleus pulposus of the intervertebral disc arises from which structure?

A) Sclerotome
B) Notochord
C) Myotome
D) Dermomyotome
E) Lateral plate mesoderm

Question 21

In Poland anomaly,which muscle is absent?

A) Transverses abdominis
B) Pectoralis major
C) Quadratus lumborum
D) External oblique
E) Superficial transverse perineal muscle

Question 22

Multiple synostoses syndrome type I is due to mutations in which gene?

A) GDF5
B) BMP5
C) LRP5
D) NOGGIN
E) BMPR1A