Chapter 9 Questions Flashcards
(11 cards)
A pediatrician notices that a new patient, a 1 1/2 y.o. boy, has a shorter that normal neck and hair farther down the neck than usual. A family history produces no evidence of other similarly affected relatives. X-ray examination reveals that the boy’s neck contains only six cervical vertebrae. The pediatrician then askes whether the mother remembers taking or being exposed to certain compounds during early pregnancy.
Which of the following does the pediatrician suspect as possibly being related to the boy’s condition?
A. Folic acid
B. Retinoic acid
C. Cocaine
D. Thalidomide
E. Alcohol
A disturbance in what class molecule is suspected to underlie this condition? A. Hox genes B. Pax genes C. Myogenic regulatory factors D. Fibroblast growth factor E. Hedgehog proteins
B. Retinoic acid
A. Hox genes
Satellite cells of muscle are activated under which of these conditions? A. Normal muscle fiber growth B. Muscle fiber regeneration C. Muscle fiber hypertrophy D. All of the above E. None of the above
D. All of the above
Which cellular component of the epidermis is a peripheral outpost of the immune system and functions to present antigens to other immune cells? A. Merkel cells B. Keratinocytes C. Basal cells D. Melanocytes E. Langerhans' cells
E. Langerhans’ cells
Which structure is mesodermal in origin? A. Hair shaft B. Mammary duct C. Sebaceous gland D. Arrector pili muscle E. None of the above
D. Arrector pili muscle
Craniosynostosis is caused by an abnormal developmental course of the: A. Foramen magnum B. Cranial structures C. Basicranium D. Jaws E. None of the above
B. Cranial structures
Which myogenic regulatory factor is expressed latest in the development of a muscle fiber? A. Myogenin B. MyoD C. MRF-4 D. myf-5 E. Pax-3
C. MRF-4
In the let down of milk during lactation, the myoepithelial cells contract in response to: A. Progesterone B. Oxytocin C. Estrogens D. Lactalbumin E. Casein
B. Oxytocin
What component of the developing skin determines the nature of the hairs that form or the thickness of the epidermis in the fetus?
The dermis.
A male patient has 2 bilaterally symmetrical brownish spots about 8mm in diameter located on the skin about 3 inches below each nipple. What is one explanation for them?
They may be supernumerary nipples located along the caudal ends of the embryonic milk lines.
Why is cranial bone typically not found over an area where part of the brain is missing?
The inductive interaction does not occur.
How was is determined that the limb musculature arises from somites?
In experiments involving the use of the quail nuclear marker, quail somites were grafted in place of the original somites in chick embryos. The muscles in the developing limbs all contained quail and not chick nuclei.
