Embryology

Question 1

Q* What is incorrect regarding the primitive steak?

Answer 1

It gives origin to the neural tube

It appears on epiblast

gives origen to endoderm

gives origin to mesoderm

Question 2

What type of connection is between mother and fetus?

Answer 2

Indirect-no direct blood contact

Question 3

The germ layer that gives rise to the organs and structures that maintain contact with outside world

Answer 3

Ectoderm

Question 4

What are the layerts of the ectoderm

Answer 4

CNS, PNS, Sensory-eyes,nose,eye

skin, hair and nails

pituitary, mammary and sweatglands and teeth enamel

Question 5

Neurolation

Answer 5

formation of neural tube and neural crest

gives orgin to all nervous tissues

CNS(spinal cord and brain)comes from neural tube

Ganglia and peripheral nerves from neural crest

Question 6

CNS(spinal cord and brain)

Answer 6

comes from neural tube

Question 7

Ganglia and peripheral nerves from

Answer 7

neural crest

Question 8

The primitive streak makes what germ layers

Answer 8

Mesoderm and Endoderm

Question 9

The ectoderm originates from what tissue

Answer 9

epiblasts

Question 10

Urinary system, what germ layer

Answer 10

mesoderm

Question 11

Reproductive system, what germ layer

Answer 11

Mesoderm

Question 12

cardiovascular system

Answer 12

mesoderm

Question 13

digestive system

Answer 13

endoderm

Question 14

skeletal system

Answer 14

mesoderm

Question 15

Tissue of the Adrenal Medulla

Answer 15

*ectoderm, (neural crest)

it is an exception

adrenal cortex is epithelial tissue and is mesoderm, but the medulla is from the neural crest

Question 16

what are neural crest derivitives

Answer 16

some bones of face

c-cells in thyroid

conotruncal septum in heart(conduction system)

ondontoblasts-teeth

Dermis of face and neck

part of meninges(forebrain only)

malanocyts

smooth muscle cells of blood vessels to face

**neural crest comes from Ectoderm

Question 17

caudal end of fetus

Answer 17

tail end

Question 18

somites on embryo forms

Answer 18

bones and muscles of back

Question 19

Anencephaly

Answer 19

neural tube fails to close in the cranial region

Question 20

what is failure of closure from the cervical region caudally on embyo

Answer 20

spina bifida

Question 21

notochord is derived from what germ layer

Answer 21

mesoderm and becomes the intervertebral disks (only place where we still have reminants)

Question 22

What is rapid division of zygote

Answer 22

cleavage

Question 23

The derivitives of the somites (what the somites evolve into)

Answer 23

myotome(muscles), sclerotome(bones&cartilage), dermatome (dermis of skin)

*somites came from the mesoderm

Question 24

urinary bladder is derived from what germ layer

Answer 24

endoderm

*small area trigon? is mesoderm

Question 25

what germ layer makes up the thyroid gland

Answer 25

endoderm

Question 26

what germ layer makes up the trachea, lungs, pancreas, liver

Answer 26

endoderm

of course the digestive tract also

Question 27

what germ layer makes the typmanic cavity and auditory tube

Answer 27

endoderm

tympanic cavity(middle ear cavity)

Question 29

once sperm enters oocyte, what occurs

Answer 29

meosis II

Question 30

Sperm survives how long

Answer 30

72 hrs

Question 31

Ovum survives how long

Answer 31

24 hrs

Question 32

When is the zygote called a blastocyst

Answer 32

when a cavity forms

day 5 implants on uterine wall, vascularization occurs now

Question 33

what marks the end of embryonic period

Answer 33

trilaminar embryonic discs form (3 germ layers)

Question 34

what are the 4 extraembryonic membranes

Answer 34

amnion-innermost layer, bag of water

Yolk sac-from hypoblasts-

allantois-forms unbilical cord

chorion-outermost-forms fetal portion of placenta and produces HCG

Question 35

what forms the ectoderm

Answer 35

epiblasts

The epiblasts form the ectoderm and the primitive streak

(the prim streak forms the mesoderm and endoderm)

(the hypoblasts dissappear)

tropoblasts-responsible for nutrients(placenta)

Question 36

what is joining of the gametes called

Answer 36

fertilization

Question 37

Sperm and oocyte have how many chromosomes

Answer 37

haploid so 23

Question 38

zygote has how many chromosomes

Answer 38

diploid, so 46