chapter 11 terms

Question 1

bone forms directly from mesenchyme&raquo_space; flat bones

Answer 1

intramembranous ossification

Question 2

cartilage model converted to bone&raquo_space; long and short bones

Answer 2

endochondrial ossification

Question 3

highly invasive slow growing tumor resulting from persistent remnant of the notochord&raquo_space; high rate of mortality

Answer 3

chordoma

Question 4

forms the base of the skull

Answer 4

cartilaginous neurocranium

Question 5

forms the calvaria

Answer 5

membranous neurocranium

Question 6

bones held together by fibrous joints

Answer 6

sutures

Question 7

large fibrous regions where sutures meet

Answer 7

fontanels

Question 8

forms bones of the middle ear plus hyoid bone&raquo_space; derived from pharyngeal arches 1-3

Answer 8

cartilaginous viscerocranium

Question 9

primarily forms bones associated with the mouth

Answer 9

membranous viscerocranium

Question 10

over 5% of the population has an abnormal number or abnormal distribution pattern

Answer 10

variation in vertebra number

Question 11

chondrification center fails to form on one side of vertebral body&raquo_space; half of vertebra never forms

Answer 11

hemivertebra

Question 12

failure of the calvaria to develop&raquo_space; other severe anomalies concurrent

Answer 12

acrania

Question 13

deformities resulting from premature closure of sutures

Answer 13

craniosynostosis

Question 14

occurs in ~1% of infants but asymptomatic until adulthood

Answer 14

anomalies of the craniovertebral junction

Question 15

autosomal dominant trait resulting in lack of long bone elongation

Answer 15

achondroplasia

Question 16

excessive secretion of growth hormone resulting in

Answer 16

congenital hyperpituitarism

Question 17

result of hypersecretion of growth hormone after epiphyseal plate has closed&raquo_space; major characteristics include large mandible, hands, feet, nose and ears

Answer 17

acromegaly

Question 18

caused by severe hyposecretion of thyroid hormone

Answer 18

cretinism

Question 19

myoblasts fuse together during fetal development&raquo_space; syncytium that may contain several hundred nuclei&raquo_space; skeletal muscle fiber

Answer 19

histogenesis

Question 20

innervated by dorsal rami of spinal nerves (slide 15)

give rise to deep extensor muscles of neck and spine

Answer 20

epaxial division

Question 21

innervated by ventral rami of spinal nerves

give rise to ventral and lateral trunk muscles, limb muscles plus back muscles acting on scapula or humerus

Answer 21

hypaxial division

Question 22

derived from pharyngeal arches

Answer 22

muscles of mastication and facial expression

Question 23

derived from preotic myotomes

Answer 23

extrinsic eye muscles

Question 24

derived from myotome regions occipital somites

Answer 24

tongue muscles

Question 25

shortened sternocleidomastoid

Answer 25

congenital torticollis (wry neck)

Question 26

failure of one or more digital rays to develop&raquo_space; results in hand/foot being divided into two parts that oppose each other

Answer 26

ectrodactyly (cleft hand/foot)

Question 27

shortness of phalanges&raquo_space; autosomal dominant trait

Answer 27

brachydactyly

Question 28

supernumerary digits&raquo_space; common autosomal dominant trait

Answer 28

polydactyly

Question 29

two or more digits fused together

Answer 29

syndactyly

Question 30

foot turned medially and inverted

Answer 30

congenital talipes (clubfoot)

Question 31

capsule of hip relaxed and underdevelopment of head of femur&raquo_space; dislocation occurs during birth

Answer 31

congenital hip dislocation

Question 32

complete and partial absence of limb&raquo_space; extremely rare other than due to thalidomide

Answer 32

amelia and meromelia