Practice Quiz - Limb Development
  1. Hair arises from which type of tissue?
    ectoderm
    mesoderm
    epidermis
    dermis
    more than one of the above
  2. Congenital absence of hair is called:
    hypertrichosis
    anonychia
    athelia or amastia
    pili torti
    atrichia or alopecia
  3. The breast develops along the mammary line/ridge, or the milk line. Which of the following is a possible site for accessory nipples or breasts?
    cubital fossa or anterior elbow
    popliteal fossa or behind the knee
    groin
    lower lateral neck above clavicle
    mid-axillary line at the 5th intercostal space
  4. Which of the following is NOT considered a "birthmark"?
    angioma
    hemangioma
    port wine stain
    ichthyosis
  5. Failure of the brain to grow may result in:
    plagiocephaly
    craniostenosis
    acrocephaly
    scaphocephaly
    microcephaly
  6. Which of the following is NOT true concerning skeletal development?
    Membrane bones include the clavicle and the bones of the cranial vault and face.
    During membrane bone formation, no cartilaginous model is formed.
    Endochondral bone formation involves calcification of cartilage, which is later replaced by true bone.
    Membrane bone lacks periosteum.
  7. Lobster claw deformity is characterized by:
    ectrodactyly
    brachydactyly
    syndactyly
    polydactyly
    more than one of the above
  8. Klippel-Feil syndrome is characterized by:
    short neck due to small cervical vertebrae
    torticollis
    high forehead
    restricted movements of the neck
  9. Somitomeres, paraxial mesoderm cranial to the somites, give rise to much of the skeletal muscle in the head EXCEPT:
    extrinsic muscles of the eye
    temporalis
    tongue muscles
    muscles of facial expression
    muscles of mastication
  10. The sphenoid bone is derived from which portion of the embryonic skull?
    cartilaginous neurocranium
    membranous neurocranium
    cartilaginous viscerocranium
    membranous viscerocranium
    branchial cartilage
  11. Which of the following is NOT true with respect to the development and growth of bones:
    Primary centers of ossification appear before the end of the third month of development.
    Almost all secondary ossification centers appear after birth.
    Longitudinal growth of a long bone occurs in the areas of the epiphyseal plates.
    Membrane bones can be recognized by their typical histological structure.
  12. Achondroplasia is characterized by all of the following EXCEPT:
    inferior sexual development
    short limbs
    average intelligence
    broad, flat face
    undershot jaw
  13. Digits which are abnormally short are called:
    syndactyly
    polydactyly
    dichuris
    amelus
    none of the above
  14. The nerve supply to a muscle can be used as an indicator of:
    the time of differentiation of a particular muscle
    the primary germ layer from which a given muscle arose
    the time of myofibril formation in the muscle
    the level of origin and path of migration of the muscle
  15. The notochord is replaced by the:
    ependyma
    vertebral column
    spinal canal
    dorsal roots
    spinal cord
  16. What gene or factor in the dorsal ectoderm is responsible for the dorsoventral axis formation of the limbs?
    Wnt-7a
    En-1
    Hox
    FGF-8
  17. What gene or factor is responsible for proximodistal axis formation of limbs?
    Wnt-7a
    En-1
    Hox
    FGF-8
  18. A newborn baby is found to have her 3rd and 4th digits fused. What is the term for this condition?
    Ectrodactyly
    Brachydactyly
    Polydactyly
    Syndactyly
    Hemimelia