Ch. 12 Book Questions Flashcards Preview

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Flashcards in Ch. 12 Book Questions Deck (11)
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1

Which of these cell and tissue types arises from cranial, but not trunk, neural crest cells?
a. Sensory ganglia
b. Adrenal medulla
c. Melanocytes
d. Schwann cells
e. None of the above

e. None of the above

2

Which molecule is a poor substrate for migrating neural crest cells?
a. Laminin
b. Chondroitin sulfate
c. Fibronectin
d. Type IV collagen
e. Hyaluronic acid

b. Chondroitin sulfate

3

Neural crest cells arise from the:
a. Somite
b. Dorsal non-neural ectoderm
c. Neural tube
d. Splanchnic mesoderm
e. Yolk sac endoderm

c. Neural tube

4

A 6-month-old infant exhibits multiple congenital defects, including a cleft palate, deafness, ocular hypertelorism, and a white forelock but otherwise dark hair on his head. The probable diagnosis is:
a. CHARGE association
b. von Recklinghausen’s disease
c. Hirschsprung’s disease
d. Waardenburg’s syndrome
e. None of the above

d. Waardenburg’s syndrome

5

What molecule is involved in the migration of neural crest cells from the neural tube?
a. Slug
b. BMP-2
c. Mash 1
d. Norepinephrine
e. Glial growth factor

a. Slug

6

Which is not a derivative of the neural crest?
a. Sensory neurons
b. Motoneurons
c. Schwann cells
d. Adrenal medulla
e. Dental papilla

b. Motoneurons

7

What maintains the competence of neural crest cells to differentiate into autonomic neurons?
a. Sonic hedgehog
b. Acetylcholine
c. Mash 1
d. Glial growth factor
e. Transforming growth factor-β

c. Mash 1

8

If trunk neural crest cells are transplanted into the cranial region, they can form all of the following types of cells except:
a. Pigment cells
b. Schwann cells
c. Sensory neurons
d. Cartilage
e. Autonomic neurons

d. Cartilage

9

How does the segmental distribution of the spinal ganglia occur?

Along the length of the spinal cord, migrating neural crest cells are funneled into the anterior sclerotomal region of the somites and are excluded from the posterior half. This results in the formation of a pair of ganglia for each vertebral segment and space between ganglia in the craniocaudal direction.

10

What are three major differences between cranial and trunk neural crests?

Cranial crest cells can form skeletal elements; trunk crest cells cannot. Migrating cranial neural crest cells have more morphogenetic information encoded in them than trunk crest cells do. (For example, craniocaudal levels are specified in cranial crest, whereas they are not fixed in trunk crest cells.) Cranial crest cells form large amounts of dermis and other connective tissues, whereas trunk crest cells do not.

11

A newborn is diagnosed as having an incomplete separation between the aorta and the pulmonary artery (a mild form of persistent truncus arteriosus). Later, after corrective heart surgery, she has more colds and sore throats than her siblings. After testing, the physician tells the parents that there is evidence of immunodeficiency. The physician also tells the parents that it would be a good idea to check her levels of parathyroid hormone.
What is the basis for this suggestion?

With the diagnosis of immunodeficiency along with the infant’s outflow tract defect of the heart, the pediatrician’s differential diagnosis included DiGeorge’s syndrome. This was confirmed when the blood levels of parathyroid hormone were found to be low. The cause of the infant’s problem probably goes back to the fourth week of pregnancy or possibly earlier, when the cranial neural crest supplying the outflow tract of the heart and pharynx was migrating or preparing to migrate into the affected regions.