Embryology II

Question 1

After the notochordal process approaches the prechordal
plate, the floor of the process “fuses” with the endoderm it is now called ___

Answer 1

notochordal plate

Question 2

what is the opening that allows communication between the amniotic cavity and the umbilical vesicle

Answer 2

neurenteric canal

Question 3

the neurenteric canal is formed where the ____ opened into the notochordal canal

Answer 3

primitive pit

Question 4

the notochordal plate progress to the ____

Answer 4

notochord

Question 5

which direction does the notochord transition go from

Answer 5

cranially –> caudally

Question 6

when is there no longer a neurenteric canal

Answer 6

after full development of the notochord

Question 7

notochordal plate cells proliferate and fold
inwards, forming the fully-developed ___

Answer 7

notochord

Question 8

The notochord is no longer a ___ canal

Answer 8

hollow

Question 9

what is between the notochord and the umbilical vesicle

Answer 9

embryonic endoderm

Question 10

the ectoderm above the notochord develops into ___

Answer 10

neural plate

Question 11

what is the stop signal for notochord development anteriorly

Answer 11

prechordal plate

Question 12

what develops into the oropharyngeal membrane

Answer 12

prechordal plate

Question 13

what is special about the oropharyngeal and cloacal membranes

Answer 13

they only have ecto and endoderm layers

Question 14

what does the cloacal membrane become

Answer 14

anus

Question 15

Small, vascularized diverticulum (outpouching) from the caudal wall of umbilical vesicle, extending into connecting stalk

Answer 15

allantois

Question 16

what day is the allantois formed

Answer 16

day 18

Question 17

Allantois functions in development of what

Answer 17

early blood formation
bladder development
uranchus

Question 18

what does the uranchus become in adults

Answer 18

median umbilical ligament

Question 19

Notochord induces overlying ectoderm to form
the neural plate is what process

Answer 19

neurulation

Question 20

what is special about neuroectodermal cells

Answer 20

tall and columnar

Question 21

what does the neuroectoderm give rise to

Answer 21

CNS
retina
other tissues from neural crest

Question 22

on day __ the neural plate invaginates to form the neural groove – neural folds are found on either side of the groove

Answer 22

18

Question 23

the neural tube is formed by ____ fusing together

Answer 23

neural folds

Question 24

the neural tube is primordium of what

Answer 24

CNS

Question 25

when does neurulation end

Answer 25

when the tube is completely closed end of week 4

Question 26

which direction do the neural crest cells migrate

Answer 26

dorso-laterally

Question 27

what CN ganglia do neural crest cells help develop

Answer 27

CN V, VII, IX, X

Question 28

what NS do the neural crest cells help develop

Answer 28

Autonomic nervous system ganglia

Question 29

neural crest cell derivatives form the _____ and ____ matter

Answer 29

arachnoid and pia

Question 30

melanocytes are derivatives of ___

Answer 30

neural crest cells

Question 31

craniofacial bone and cartilage are derivatives of ____ cells

Answer 31

neural crest

Question 32

Intraembryonic mesoderm proliferates to form a thick column of mesoderm on either side of the notochord beside the axis is called what

Answer 32

paraxial mesoderm

Question 33

cuboidal masses of mesoderm on either side of the notochord, visible along the dorso-lateral surface of the embryo on each side of the neural tube

Answer 33

somite

Question 34

somites give rise to:

Answer 34

axial skeleton, musculature and dermis of area

Question 35

cardiogenic mesoderm gives rise to __

Answer 35

embryonic heart primordia

Question 36

on day __ the embryonic heart primorda is formed

Answer 36

20

Question 37

primordium of _____ appears as isolated spaces in the lateral mesoderm and cardiogenic mesoderm

Answer 37

intraembryonic coelom

Question 38

what shape is the intraembryonic coelom formed into

Answer 38

single horseshoe

Question 39

what are the 2 layers that the intraembryonic coelom divides the lateral mesoderm into

Answer 39

1. somatic /parietal layer 2. splanchnic / visceral layer

Question 40

what layer of lateral mesoderm covers the amnion

Answer 40

somatic or parietal layer

Question 41

what layer of the lateral mesoderm covers the umbilical vesicle

Answer 41

splanchnic or visceral layer

Question 42

on day ___ the coelomic spaces are a continuous cavity

Answer 42

21

Question 43

the somatic mesoderm and the overlying ectoderm later forms the body wall

Answer 43

somatopleure

Question 44

the splanchnic mesoderm and the underlying intraembryonic endoderm later forms the embryonic gut

Answer 44

splanchnopleure

Question 45

what is between the somatopleure and splanchnopleure

Answer 45

intraembryonic coelom

Question 46

intraembryonic coelom develops into 3 main body cavities which are

Answer 46

1. pericardial cavity 2. pleural cavity 3. peritoneal cavity

Question 47

The bilaminar embryonic disc is converted into a trilaminar embryonic disc during

Answer 47

gastrulation

Question 48

the ___ results from migration of epiblastic cells to the median plane of the disc

Answer 48

primitive streak

Question 49

Invagination of epiblastic cells from the primitive streak gives rise to mesenchymal cells that migrate ventrally, laterally, and cranially between the

Answer 49

epiblast and hypoblast

Question 50

As soon as the primitive streak begins to produce mesenchymal cells, the epiblast is known as

Answer 50

embryonic ectoderm

Question 51

Some cells of the epiblast displace the hypoblast and form

Answer 51

embryonic endoderm

Question 52

the anterior and posterior ends of the embryo move ventrally. Also known as cranial-caudal folding

Answer 52

median plane

Question 53

the lateral edges of the embryonic disk move ventrally. Also known as lateral folding * The edges “roll” ventrally towards the umbilical vesicle

Answer 53

horizontal folding

Question 54

when does embryonic folding occur

Answer 54

start in end of 3rd week see at 4th week

Question 55

As it folds ___, the brain vesicles first begin to appear, and a few somites are obvious

Answer 55

cranially

Question 56

As it folds ___, the body wall is formed

Answer 56

laterally

Question 57

Part of the endoderm of the umbilical vesicle is incorporated into the embryo as the

Answer 57

foregut

Question 58

what is the foregut between

Answer 58

brain and heart

Question 59

the primordium of the mouth

Answer 59

stomedeum

Question 60

what separates the foregut form the stomodeum

Answer 60

oropharyngeal membrane

Question 61

develops into the central tendon of the diaphragm and separates the abdominal cavity from the thoracic cavity

Answer 61

spetum transversum

Question 62

the location of the heart changes based on what

Answer 62

head fold

Question 63

what is primordium of the umbilical cord

Answer 63

connecting stalk

Question 64

after lateral folding, the connection between the midgut and umbilical vesicle is reduced to an ___ duct

Answer 64

omphaloenteric duct

Question 65

connective tissue; cartilage; bone * striated and smooth muscles; heart, blood, and lymphatic vessels; kidneys; * ovaries; testes; genital ducts; serous membranes lining the body cavities (pericardial, pleural, and peritoneal); spleen; and cortex of suprarenal glands

Answer 65

mesoderm derivatives

Question 66

epithelial lining of the digestive and respiratory tracts, parenchyma of the tonsils * thyroid and parathyroid glands, thymus * liver, and pancreas, epithelial lining of the urinary bladder and most of the urethra * epithelial lining of the tympanic cavity, tympanic antrum, and eustachian tube

Answer 66

endoderm derivatives

Question 67

CNS, PNS; sensory epithelia of the eyes, ears, and nose * epidermis and its appendages (hair and nails); mammary glands; subcutaneous glands; enamel of teeth; pituitary gland * Neural crest cells – discussed previously

Answer 67

ectoderm derivatives

Question 68

on day __ the neural plate can be seen

Answer 68

19

Question 69

on day __ neurulation is complete with closure of neuropores

Answer 69

27

Question 70

on day __ the cranial 2/3 of the neural tube makes the brain and the caudal 1/3 makes the spinal cord

Answer 70

22

Question 71

The neural folds fuse at the level of the ___ somite, proceeds cranially and caudally

Answer 71

5th