Ch. 9 Book Questions Flashcards
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 sutures
c. Basicranium
d. Jaws
e. None of the above
b. Cranial sutures
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. Recombination experiments have clearly shown that the dermis confers regional morphogenetic information on the epidermis and instructs it to form, for example, cranial hair or abdominal hair.
A male patient has two bilaterally symmetrical brownish spots about 8 mm 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?
In the early embryo, brain tissue induces the formation of the surrounding membranous skeletal elements. If a significant region of the brain is missing, the inductive interaction does not occur.
How was it determined that the limb musculature arises from the 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.
What happens in the vertebral column when you knockout all Hox 10 paralogues?
Ribs form on all the lumbar and sacral vertebrae
Individual mammary placodes form from aggregation and proliferation of ectodermal cells of the milk line under the inductive influence of which signaling molecule?
neuregulin-3
In the adult hair cycle, when does the hair follicle regress to only a fraction of its original length?
Catagen
Expression of ____ via the signaling pathway involving Edar receptor stimulates formation of dermal papilla below epidermal placode.
SHH
__________ contributes to the hair follicle, hair shaft, sebaceous glands, nails (plate), eponychium (cuticle), hyponychium (tip of finger/toe), and secretory and duct components of the mammary glands.
Ectoderm
