All of the essential features
of the external body form are completed by the end of the _____ week.
Thirth
Fourth
Fifth
Sixth
Eight
eight
"Quickening" or the
period when fetal movements are commonly first felt by mother occurs:
Near the end of the first trimester.
Around the middle of the second trimester.
At the end of the second trimester.
At the end of the embryonic period.
At the end of the fetal period.
middle of the second semester.
5th month of pregancy
but they start at the end of the 1st trimester
Mesoderm lateral to the notochord :
is derived from the hypoblast
differentiates into ganglia
migrates cranial to prochordal plate
induces endoderm differentation
arises from invagination of the epiblast at the primitive streak
arises during the 3rd week
Migrates cranial to the prochordal plate
arises from the invagination of the epiblast at the primitive streak
arises during the 3rd week
The following organs are
derived from mesoderm except:
Skeletal musculature.
Musculature of blood vessels.
Cardiac musculature.
Suprarenal cortex.
Suprarenal medulla.
suprarenal medulla
suprareanl medulla or adrenal medulla arises from what?
neural crest cells and they are ectodermal
Paraxial (somatic) mesoderm gives rise to:
Muscles in the stomach.
Vertebrae.
Muscles of mastication.
Musculature of the trunk and extremities.
vertebrae
musculature of trunk and extremeties
muscles of mastication arise from the 1st pharyngeal arch
muscles of stomach arise from the lateral plate mesoderm
The endodermal germ layer gives rise to the epithelium and wall of the gastrointestinal tract.
True.
False.
false
epithelium of the wal of gastrointestinal tract comes from endoderm BUT the wall of the tract arises from the visceral layer of the lateral plate mesoderm
During the fourth week of
development, the growth of head, tail and lateral folds transforms the flat germ disc into a tubular embryo.
True.
False.
true
Somites:
Differentiate into myotomes which give rise to skeletal muscle in trunk and limbs
Differentiate into sclerotomes which give rise to vertebrae
Arise from segmentation of the paraxial mesoderm
Differentiate into myotomes which give rise to skeletal muscles of the limbs.
Differentiate into dermatomes which give rise to dermal skin components
Differentiate into myotomes which give rise to skeletal mucle in trunk and limbs
Differentiate into scleretomes which give rise to vertebrae
Arise from segmentation of the paraxial mesoderm
Differentiate into myotomes which give rise to skeletal muscles of the limbs
Differentiates into dermatomes which give rise to dermal components of the skin
Following are four structures
together with a germ layer. Identify the INCORRECT association.
Epithelium of the pancreas –endoderm.
Hair – ectoderm.
Bone – mesoderm.
Epithelium of the lung –mesoderm.
epithelium of the lung -mesoderm
the epithelium of the lung and pancreas is endodermal indicating origin from the primitive gut
Of the following, which is derived from endoderm?
Muscle.
Kidneys.
Gonads.
Tonsils
Hair.
tonsils
tonsils arise from endodermal epithelium lining the 2nd pharyngeal arch
kidneys and gonads arise from the intermediate mesoderm
hair is ectodermal
skeletal mucle comes from somites and somitomeres
cardiac and most smooth muscle comes from splanchnic mesoderm.
some smooth mucle comes from neural crest
Which of the following structures is NOT derived from mesenchyme?
Muscle fiber.
Cartilage of the limbs.
White blood cell precursor.
Epidermis.
Blood vessel
epidermis
what's the origin of dermis?
mesenchyme
Of the following, which is derived from endoderm?
Hypophysis.
Epithelium of the pharynx.
Epithelium of anal canal.
Enamel of teeth.
Muscle
epithelium of pharynx
Epithelium of the anal canal is derived from what?
lower part - ectoderm
upper part- endoderm
how do we call the border between the ectodermal and endodermal lining in the anal canal?
Pectinate line
During the period of development of the major organ systems, development of the major organ systems,
development and differentiation appears first in what region?
Head.
Tail.
Mid-embryo.
Distal third.
Mid-third
head
At the beginning of the fourth week, day 22, there are about 7-10 somites present. About how many are there at
the end of the fourth week, day 28?
7-10.
10-13.
20-23.
26-29.
42-44
26 to 29
Almost all internal organs are well laid down at ______ months:
1.
2.
3.
4.
5.
2 months
The space between the split
layers of mesoderm is the:
Amniotic cavity.
Blastocele.
Foregut.
Hindgut
Intraembryonic coelom
intraembryonic coelon
Which of the following are NOT distinctive characteristics of the fourth week of development?
Neuropores.
Somites.
Branchial arches.
Lower limb buds.
Hand plates
Foot plates
Hand plates
Foot plates
6th weeks
Which of the following are distinctive characteristics of the fourth week of development?
Neuropores.
Somites.
Branchial arches.
Lower limb buds.
Hand plates.
neuropores
somites
branchial arches
lower limbs buds
During human embryonic development:
The inner cell mass develops into fetal portion of the placenta.
The yolk sac stores nutrients for the first four weeks of development.
The allantois stores waste products.
The location of cells in the morula dictates their fate.
the location of thecells in the morula dictates their fate
During the human embryonic development, the inner cell mass develops into what?
embryo proper
During the human embryonic development, what's the nutritive function of the yolk sac?
none
During the human embryonic development, the allantoins serves for what?
in humans nothing
in animals stores waste products
Which of the following structures does not turn under onto the ventral surface of the embryo during folding of the head?
Prechordal plate.
Heart.
Notochord.
Pericardial cavity.
Septum transversum
Notochord - it remains dorsal
Which of the following structures turn under onto the ventral surface of the embryo during folding of the head?
Prechordal plate.
Heart.
Notochord.
Pericardial cavity.
Septum transversum.
buccopharyngeal membrane
prechordal plate
heart
pericardial cavity
septum transversum
buccopharyngeal membrane
At birth, the crown-rump length
of the newborn averages __ cm
19.
28.
35.
44.
52.
35
the crown-rump lenght of the fetus measures what?
fetus sitting heigh.
most of the fetus growth in lenght occurs early in the fetal period .
most of the fetal growth in weight occurs late in the fetal period
The embryo is called a fetus after
the:
Third week.
Second month.
Third month.
Fourth month.
Fifth month.
second month
Lanugo covers the body, some head hair show, and fetal movements are felt by the mother when the fetus is about how many moths old?
5.
6.
7.
8.
9
5th month
what's the vernix caesosa?
greasy, whittish film covering the skin of the fetus
protects the fetal skin from maceration by the amniotic fluid.
Which of the following statements about fetal age and weight shows a normal relationship?
8 weeks - 10g
12 weeks - 300g
20 weeks - 800g
26 weeks - 1000g
38 weeks - 4600g
26 weeks -1000g
full term fetus -300-3400 g
Which of the following structures is derived from paraxial mesoderm of the cervical region?
Enamel of the teeth.
Smooth muscle of the gut.
Mucous linning of the larynx.
Sympathetic chain ganglia.
Ureter.
Suprarenal medulla.
Patella.
Skeletal muscle of the upper limb.
Parietal peritoneum.
Linning of the lungs.
Spinal cord.
Parenchyma of the pancreas.
Eleventh thoracic vertebra.
Aortic arch.
skeletal muscle of the upper limb
the paraxial mesoderm forms somites which give rise to axial skeleton and CT of trunk, all skeletal muscle and dermis.
in the lower cervical regions , the somitic myotomes form the skeletal muscle of the developing upper limb
Which of the following is derived from the splanchnic layer of the layer of the lateral plate mesoderm?
Enamel of the teeth.
Smooth muscle of the gut.
Mucous linning of the larynx.
Sympathetic chain ganglia.
Ureter.
Suprarenal medulla.
Patella.
Skeletal muscle of the upper limb.
Parietal peritoneum.
Linning of the lungs.
Spinal cord.
Parenchyma of the pancreas.
Eleventh thoracic vertebra.
Aortic arch.
smooth muscle of the gut
Which of the following is derived from the intermediate mesoderm?
Enamel of the teeth.
Smooth muscle of the gut.
Mucous linning of the larynx.
Sympathetic chain ganglia.
Ureter.
Suprarenal medulla.
Patella.
Skeletal muscle of the upper limb.
Parietal peritoneum.
Linning of the lungs.
Spinal cord.
Parenchyma of the pancreas.
Eleventh thoracic vertebra.
Aortic arch.
Kidneys
ureter
kidneys
paraxial mesoderm - somites abd their derivatives
somatic layer of lat plate mesoderm - CT of body wall and limbs
splanchnic layer of lat plate mesoderm - CT of gut wall