Development Of Face And Skeletal System

Question 1

The skull bones:

a) their primordia develop from the head mesenchyme
b) develop from the ectoderm
c) can be divided in the chondrocranium and desmocranium
d) are fully ossified including fontanellae before birth

Answer 1

A,c

Question 2

The skull bones develop from the head mesenchyme which originates from:

a) the mesoderm of the prechordal plate
b) from cranial somites
c) from the neural crest
d) the entoderm of primitive gut

Answer 2

A,b,c

Question 3

Chondrocranium:

a) develops on the basis from cranial somites
b) forms the skull base
c) develops as a continuation of the cervical vertebral column
d) comes from the entodermal lining of the primitive gut

Answer 3

A,b,c

Question 4

Which statements are correct about the chondrocranium development?

a) the first 3–4 cranial somites are transformed in a paired cartilage – parachordalia

b) the frontal ends of the parachordalia surround the pituitary as the catilago
hypophysealis

c) the parachordalia and trabeculae cranii extend caudally
d) it does not ossify

Answer 4

A,b

Question 5

Which statements are correct about the chondrocranium development?

a) it develops into capsules for sense organs
b) it is formed by the entodermal lining of the primitive gut
c) the parachordalia and trabeculae cranii extend cranially and laterally to form a continuous skull base
d) it ossifies in an enchondral way

Answer 5

A,c,d

Question 6

The skeletal derivatives of the branchial (pharyngeal) arches:

a) come from the mesoderm as in the skull base
b) are derivatives of the neural crest
c) come from ectomesenchyme of neuroectodermal origin
d) come mainly from the entoderm

Answer 6

B,c

Question 7

The development of the lower jaw:

a) starts as a cartilaginous jaw
b) starts as the Rathke’s pouch
c) is characterized by desmogenous ossification in the connective tissue around the Meckelian cartilage
d) is completed before the 3rd week of embryonic development

Answer 7

A,c

Question 8

Desmocranium:

a) consists from the bones of the skull vault
b) consists of the facial bones (viscerocranium)
c) consists of the definitive mandible and maxilla
d) comprises the Rathke’s pouch

Answer 8

A,b,c

Question 9

During the development of the desmocranium:

a) the developing bones of the vault including the fontanelles fuses completely
before birth

b) the developing bones of the vault extend and reduce the connective tissue in narrow clefts called sutures
c) the first 3–4 cranial somites are transformed in desmocranium
d) anterior fontanella closes till the end of the 2nd postnatal year

Answer 9

B,d

Question 10

During the development of the desmocranium:

a) the anterior fontanella closes always under normal conditions before birth
b) the posterior fontanella closes by the end of the 1st year
c) the small lateral fontanelles close during the first postnatal months
d) the first 3–4 cranial somites are transformed in desmocranium

Answer 10

B,c

Question 11

Which statements are true about facial structures development?

a) it is influenced by the prosencephalic bulging
b) the eyes are situated at first laterally
c) the pinnas of ears are situated on the top of the head at first
d) the nose develops independently just before birth

Answer 11

A,b

Question 12

Which statements are true about facial structures development?

a) it is influenced by the prosencephalic bulging
b) the pinnas of ears are situated in a low position at the neck level

c) the frontal process bulges over the stomodeal cavity during the 4th week of
embryonic development

d) the presence of the nasal bone is an important sign for ultrasound diagnostics
during the 2nd trimester

Answer 12

A,b,c,d

Question 13

Which statements are true about facial structures development?

a) the absence of the nasal bone is a powerful marker for Down syndrome during the 2nd trimester

b) a short nasal bone is associated with an increased likelihood for fetal Down
syndrome

c) the fetus can swallow the amniotic fluid already before the birth

d) the facial structures are not visible during the ultrasound examination in the
2nd trimester

Answer 13

A,b,c

Question 14

The nose:

a) starts its formation in form of two proliferative thickening of ectoderm
b) develops from the Rathke’s pouch
c) starts its formation on the basis of olfactory placodes

d) is visible during the prenatal ultrasound examination already during the first
trimester screening

Answer 14

A,c,d

Question 15

Which statements about nose development are correct?

a) the olfactory placodes invaginate and form vesicles
b) the olfactory placodes develop in nasal tubes
c) the nasal tubes epithelium blends with the epithelium of the stomodeal roof
d) the development of the nose can be abnormal in cases of CNS malformation

Answer 15

A,b,c,d

Question 16

Which statements about nose development are correct?

a) the nasal tubes epithelium blends with the epithelium of the stomodeal roof
b) the nasal tubes epithelium contributes to the epithelial fin that separates the lateral mesenchyme of the future maxilla from the middle mesenchyme of pre- maxilla
c) the Rathke’s pouch develops into nasal tubes
d) Meckelian cartilage forms the olfactory placodes

Answer 16

A,b

Question 17

Which statements about nose development are correct?

a) the final form of the nose develops through lifting of a triangular “nasal field”
above the circumnasal ridges

b) the nasal wings arise from the lateral parts of the circumnasal ridges

c) the nostrils point at first ventrally and then turn down after the development
of the nasal skeleton

d) Meckelian cartilage forms the olfactory placodes

Answer 17

A,b,c

Question 18

The primary palate:

a) is formed by the maxilla and premaxilla,
b) the epithelial fin between maxilla and premaxilla colapses due apoptosis
c) the mesenchyme of maxilla and premaxilla fuses
d) the Rathke’s pouch has to double to form the palate

Answer 18

A,b,c

Question 19

Cleft lip and jaw:

a) is caused by the Rathke’s pouch anomalies

b) appear in cases when the apoptosis does not destroy the epithelial fin between
maxilla and premaxilla

c) can be unilateral or bilateral

d) is always (in 100% of cases) associated with the central nervous system malfor-
mations

Answer 19

B,c

Question 20

Primitive choane:

a) connects the olfactory tube with the stomodeum
b) is formed at the 3rd week of embryonic development
c) is formed by fontanelles
d) appears after a collapse of the oronasal membrane due to apoptosis

Answer 20

A,d

Question 21

During facial development:

a) eyes are shifted from their lateral position ventrally
b) the primary palate is formed by maxilla and premaxilla
c) the primitive choane develop from Rathke’s pouch
d) ears are shifted from the neck region to the level of mouth

Answer 21

A,b,d

Question 22

The definitive palate:

a) is formed from the palatal processes that grow from the maxillary and prema-
xillary processes

b) the palatal processes stay isolated and do not connect
c) is formed during the 3rd week of embryonic development

d) becomes replaced during the 4th week of embryonic development by the oronasal
membrane

Answer 22

A

Question 23

Holoprosencephaly:

a) is a cephalic disorder in which the prosencephalon fails to develop properly

b) can be associated with cyclopia, an abnormality characterized by the develop-
ment of a single eye

c) can be associated with the proboscis, a tubular appendage located above the
eye

d) can be treated surgically

Answer 23

A,b,c

Question 24

Cleft lip:

a) the cleft affects the palate structure
b) is formed in the top of the lip as either a small gap or an indentation in the lip
c) occurs always together with central nervous system malformations
d) it is caused by failure of fusion of the maxillary and medial nasal processes

Answer 24

B,d

Question 25

Cleft lip:

a) the cleft does not affect the palate structure
b) is formed in the top of the lip as either a small gap or an indentation in the lip
c) can occur as a one sided (unilateral) or two sided (bilateral)
d) it is caused by failure of primary palate formation

Answer 25

A,b,c,d

Question 26

The limbs develop:

a) in the blastocyst stage from the syncytiotrophoblast primordium
b) as folds of the body wall in form of buds
c) from the 4th week of embryonic development
d) during the morula formation

Answer 26

B,c

Question 27

The fore-limb buds:

a) develop as folds of the body wall
b) develop two days later than the hind ones
c) are formed by mesenchyme covered by ectoderm
d) are covered by entoderm

Answer 27

A,c

Question 28

The fore-limb buds:

a) develop as folds of the body wall
b) develop two days earlier then the hind ones
c) are formed by trophoblast
d) are covered by the ectoderm

Answer 28

A,b,d

Question 29

The surface epithelium of limb buds:

a) is originally simple
b) is of ectodermal origin
c) becomes stratified on the tip of the bud to form the apical ectodermal ridge

d) forms the epidermis which consists of simple squamous epithelium in the adul-
thood

Answer 29

A,b,c

Question 30

The upper limb bud:

a) contains mesenchyme and is covered by the ectoderm
b) is vascularized from the 7th intersegmental artery
c) develops at the 2nd week of embryonic development
d) develop two days later then the lower ones

Answer 30

A,b

Question 31

The lower limb bud:

a) contains mesenchyme and is covered by the entoderm
b) is vascularized from the 5th lumbar artery
c) develops at the 2nd week of embryonic development
d) develop two days later then the upper limb bud

Answer 31

B,d

Question 32

During limb development:

a) the mesenchyme inside limb buds condenses from the proximal to the distal end
in chondroblasteme of the limb skeleton

b) the superficial entoderm forms the apical ridge
c) the upper limb bud is vascularized from the 7th lumbar artery
d) the lower limb bud is vascularized from the 5th lumbar artery

Answer 32

A,d

Question 33

Which statements are correct about limb development?

a) the proximal segment is formed by a single bone
b) the middle segment is called the zeugopodium
c) the distal segment gives rise to only one bone

d) the chondroblastems of all five digital rays begins to be separated during 6th to
7th month by cell apoptosis of the interdigital mesenchyme

Answer 33

A,b

Question 34

Which statements are correct about limb development?

a) the proximal segment is called the stylopodium
b) the proximal segment is formed by a single bone
c) the humerus develops in the proximal segment
d) the ulna develops in the proximal segment

Answer 34

A,b,c

Question 35

Which statements are correct about limb development?

a) the middle segment is called the zeugopodium
b) the middle segment is always formed by a pair of bones
c) the radius and ulna or the tibia and fibula develop in the middle segment

d) if the middle segment regresses completely, the other two segments, proximal
and distal, develop in complete healthy extremity with no malformation

Answer 35

A,b,c

Question 36

Which statements are correct about limb development?

a) the distal segment gives rise to femur or humerus
b) the distal segment is called autopodium
c) the distal segment represents the hand or foot with five digits
d) ulna develops in the distal segment

Answer 36

B,c

Question 37

Which statements are correct about finger development?

a) the chondroblastema of all five digital rays begin to be separated during 6th to
7th week of the embryonic development

b) the chondroblastema begin to be separated by cell apoptosis of the interdigital
mesenchyme

c) they develop in the middle limb segment
d) they develop from the stylopodium

Answer 37

A,b

Question 38

Which statements are correct about limb development?

a) primary ossification centres appear in cartilaginous models of the limb skeleton
during the 8th week of embryonic development

b) the secondary centers develop after birth
c) there have to be all three segments develop to form a normal extremity
d) apoptosis is one of the necessary mechanisms during limb development

Answer 38

A,b,c,d

Question 39

Syndactyly:

a) is the multiplication of digits,

b) is a malformation caused by the faults of apoptosis in the interdigital mesen-
chyme

c) syndactyly of the border digits has too be treated at early age to prevent the
larger digit from curving towards the smaller digit with growth

d) syndactyly is treated usually at 6 to 24 months of age

Answer 39

B,c,d

Question 40

Which statements are correct about limb development?

a) the upper limbs are innervated from the Th7 nerve
b) the lower limbs are innervated from L1–S2 nerves,
c) the upper limb bud is vascularized from the 7th intersegmental artery
d) the lower limb bud is vascularized from the 1st lumbar artery

Answer 40

B,c

Question 41

Which statements are correct about limb development?

a) the upper limbs are innervated from the C5–Th1 nerves
b) the lower limbs are innervated from L1–S2 nerves
c) the upper limb bud is vascularized from the 5th intersegmental artery
d) the lower limb bud is vascularized from the 5th lumbar artery

Answer 41

A,b,d

Question 42

The nails:

a) begin to develop in the 3rd month of fetal development
b) before delivery, they reach to the tips of digits
c) their size and status are one of the signs of newborn maturity
d) are fully developed before the 3rd week of embryonic development

Answer 42

A,b,c

Question 43

The vertebral column:

a) develops around the notochord

b) develops from the paraxial mesoderm that starts to be segmented during the
4th week of embryonic development

c) develops from the Rathke’s pouch
d) develops from the stylopodium, zeugopodium and autopodium

Answer 43

A,b

Question 44

Which statements are correct about somite development?

a) there are 18 somites during the development
b) the somites do not correspond to the vertebral segmentation completely
c) some somites are contribute to the the skull basis development
d) the mesodermal tissue of the somite disintegrates later into mesenchyme

Answer 44

B,c,d

Question 45

Which statements are correct about somite development?

a) there are 38–40 somites during the development
b) somites mesenchyme divide into dermatome, myotome and sclerotome

c) the medially situated mesenchymal cells of sclerotome migrate towards the no-
tochord and gradually surround it

d) each sclerotome divides in two halves – the cranial and caudal ones

Answer 45

A,b,c,d