embryology

Question 1

what is the name for a fertilised ovum?

Answer 1

zygote

Question 2

what is a morula?

Answer 2

mass of cells

Question 3

how many days in to a pregnancy is a morula formed?

Answer 3

4-6

Question 4

what is a blastocyst?

Answer 4

hollow ball of cells with inner cell mass

Question 5

when during pregnancy is a blastocyst formed?

Answer 5

6-10 days

Question 6

how is the baby and mothers blood mixing prevented?

Answer 6

they are separated by a thin barrier known a the placenta

Question 7

what is the placenta permeable to?

Answer 7

most molecules other than cells

Question 8

when the embryonic inner cell mass forms 2 layers it is referred to?

Answer 8

bilaminar embryo

Question 9

at how many days does the embryo become a bilaminar embryo?

Answer 9

10-12

Question 10

what are the 2 layers of the bilarminar embryo called?

Answer 10

epiblast and hypoblast

Question 11

what us the function of the epiblast in the bilaminar embryo?

Answer 11

gives rise to embryonic ectoderm

Question 12

what us the function of the hypoblast in the bilaminar embryo?

Answer 12

participates in formation of endoderm and extra embryonic mesoderm

Question 13

which twins are formed by splitting before fertilisation?

Answer 13

fraternal

Question 14

which twins are formed from 1 egg?

Answer 14

identical

Question 15

what is gastrulation of the embryo?

Answer 15

it forms an axis and 3 embryonic layers

Question 16

what is the groove formed during gastrulation known as?

Answer 16

primitive streak

Question 17

which 2 layers form the endoderm?

Answer 17

mesoderm and hypoblast

Question 18

which cells form the mesoderm?

Answer 18

ectodermal cells

Question 19

what is the name given to the early 3 layered embryo?

Answer 19

trilaminar embryo

Question 20

what does the primitive streak develop into?

Answer 20

neural tube

Question 21

when does the neural tube develop?

Answer 21

3-8 weeks

Question 22

what is the name given to the development of organs from the 3 basic germ layers?

Answer 22

organogenesis

Question 23

what is one of the 1st organs to form in an embryo?

Answer 23

CNS

Question 24

what embryonic structure forms the CNS?

Answer 24

neural tube

Question 25

what is the name of the 4th embryonic layer?

Answer 25

ectomesenchyme

Question 26

which layer forms the ectomesenchyme?

Answer 26

ectoderm

Question 27

which layer of the embryo is important for the development of the head?

Answer 27

ectomesenchyme

Question 28

when in the development of an embryo does it start to take shape?

Answer 28

4 weeks

Question 29

at which point in the development of a foetus does it have developed organs ?

Answer 29

9 weeks

Question 30

when does an embryo become a foetus?

Answer 30

9 weeks

Question 31

name the 3 cell types that all body cells come from

Answer 31

ectoderm (outer covering) mesoderm (middle) and endoderm (inner lining)

Question 32

what structures does the ectoderm produce?

Answer 32

skin, mucous membrane, brain, spinal cord, TOOTH ENAMEL

Question 33

what structures does the mesoderm produce?

Answer 33

connective tissue, muscle, blood vessels, kidneys, urinary system, reproductive system, serous membranes

Question 34

what structures does the endoderm produce?

Answer 34

alimentary canal, respiratory system, urogenital organs

Question 35

which stem cells are totipotent?

Answer 35

embryonic

Question 36

which stem cells are pluripotent?

Answer 36

adult

Question 37

what structures does the ectomesenchyme produce?

Answer 37

PNS, melanocytes, adrenal medulla, mesenchyme in head, DENTIN, PULP, PDL, JAW BONES

Question 38

which period of pregnancy is of greatest sensitivity?

Answer 38

week 3-12

Question 39

at which point of pregnancy do most developmental abnormalities occur?

Answer 39

week 3-12

Question 40

which structure dives the ectoderm to proliferate to form the neural tube?

Answer 40

notochord

Question 41

during development of the neural tube 2 clusters form above, these are known as?

Answer 41

neural crest

Question 42

what tissue is the neural crest derived from?

Answer 42

ectoderm

Question 43

what does the neural crest form?

Answer 43

ectomessenchyme

Question 44

are stem cells from the 3 germ layers totipotent or pluripotent?

Answer 44

pluripotent