Anatomy_Key Terms_Ch3

Question 1

prenatal period

Answer 1

”"”before birth”” is the time between conception (the union of a egg and a sperm cell) and birth”

Question 2

embryonic period

Answer 2

first 8 weeks of the prenatal period

Question 3

fetal period

Answer 3

remaining 30 weeks of the prenatal period

Question 4

embryo

Answer 4

technically, the stage in prenatal development between the third or fourth and eighth weeks inclusive. However, informally can encompass all stages (the early form of the body)

Question 5

fetus

Answer 5

”"”the young in the womb”””

Question 6

oocyte

Answer 6

immature egg

Question 7

zygote

Answer 7

“fertilized oocyte (““a union””)”

Question 8

cleavage

Answer 8

early division of cells, in which they multiply but grow smaller and smaller due to lack of time for cell growth

Question 9

morula

Answer 9

”"”mulberry””, 12-16 cells generated by cleavage by about 72 hours after fertilization”

Question 10

blastocyst

Answer 10

”"”bud or sprout; bag””, during day 4 the late morula (now ~60 cells) enters the uterus, takes up fluid which gathers into a central cavity–the new fluid-filled struture is called”

Question 11

inner cell mass

Answer 11

cluster of cells on one side of the blastocyst cavity

Question 12

trophoblast

Answer 12

(tropho=nourishment), the layer of cells surrounding the cavity

Question 13

implantation

Answer 13

blastocyst starts to burrow into the wall of the uterus (day 6 for about a week)

Question 14

bilaminar embryonic disc

Answer 14

made up of the epiblast and the hypoblast, 2 sheets of cells whose extensions form two fluid-filled sacs (about 9 days after fertilization)

Question 15

amnion

Answer 15

outer membrane of the amniotic sac (formed by an extension of the eiblast)

Question 16

amniotic sac cavity

Answer 16

“filled with amniotic fluid, buffers the developing embryo and fetus from physical shock until the time of birth (the water in ““water broke””)”

Question 17

yolk sac

Answer 17

formed by an extension of the hypoblast, holds insignificant amount of yolk but the digestive tube forms from part of it; tissue around the ylok sac gives rise to the earliest blood cells and blood vessels

Question 18

gastrulation

Answer 18

embryo grows from a two-layered disk to a three-layered disc during week 3; forms the three primary germ layers (ectoderm, mesoderm, and endoderm), the layers from which all body tissues develop

Question 19

primitive streak

Answer 19

raised groove appears on the dorsal surface of the eiblast days 14-15; epiblast cells migrate inward at this streak

Question 20

endoderm

Answer 20

the first cells that migrate through the primative streak displace the cells of the underlying hypoblast to become the endoderm (day 14-15)

Question 21

mesoderm

Answer 21

(starting on day 16) the ingressing (through primitive streak) epiblast cells form a new layer between epiblast and endoderm, the mesoderm

Question 22

ectoderm

Answer 22

“the epiblast cells that remain on the embryo’s dorsal surface make up the ectoderm”

Question 23

epithelial tissues

Answer 23

or epithelia, sheets of tightly joined cells

Question 24

mescenchyme tissue

Answer 24

”"”middle fluid””, any embryonic tissue with star-shaped cells that do not attach to one another”

Question 25

primitive node

Answer 25

at one end of the primitive streak; cells go to form the notochord

Question 26

notochord

Answer 26

defines the body axis and is the site of the future vertebral column (appears on day 16, and by day 18 it reaches the future head region)

Question 27

neurulation

Answer 27

the forming of the spinal cord and brain

Question 28

induction

Answer 28

the ability of one group of cells to influence the developmental direction of other cells

Question 29

primitive gut

Answer 29

develops into the digestive tube and respiratory structures

Question 30

limb buds

Answer 30

the first rudiments of the limbs appear around day 28

Question 31

premature births

Answer 31

one that occurs before 38 weeks after conception

Question 32

"""before birth"" is the time between conception (the union of a egg and a sperm cell) and birth"

Answer 32

prenatal period

Question 33

first 8 weeks of the prenatal period

Answer 33

embryonic period

Question 34

remaining 30 weeks of the prenatal period

Answer 34

fetal period

Question 35

technically, the stage in prenatal development between the third or fourth and eighth weeks inclusive.  However, informally can encompass all stages (the early form of the body)

Answer 35

embryo

Question 36

"""the young in the womb"""

Answer 36

fetus

Question 37

immature egg

Answer 37

oocyte

Question 38

"fertilized oocyte (""a union"")"

Answer 38

zygote

Question 39

early division of cells, in which they multiply but grow smaller and smaller due to lack of time for cell growth

Answer 39

cleavage

Question 40

"""mulberry"", 12-16 cells generated by cleavage by about 72 hours after fertilization"

Answer 40

morula

Question 41

"""bud or sprout; bag"", during day 4 the late morula (now ~60 cells) enters the uterus, takes up fluid which gathers into a central cavity--the new fluid-filled struture is called"

Answer 41

blastocyst

Question 42

cluster of cells on one side of the blastocyst cavity

Answer 42

inner cell mass

Question 43

(tropho=nourishment), the layer of cells surrounding the cavity

Answer 43

trophoblast

Question 44

blastocyst starts to burrow into the wall of the uterus (day 6 for about a week)

Answer 44

implantation

Question 45

made up of the epiblast and the hypoblast, 2 sheets of cells whose extensions form two fluid-filled sacs (about 9 days after fertilization)

Answer 45

bilaminar embryonic disc

Question 46

outer membrane of the amniotic sac (formed by an extension of the eiblast)

Answer 46

amnion

Question 47

"filled with amniotic fluid, buffers the developing embryo and fetus from physical shock until the time of birth (the water in ""water broke"")"

Answer 47

amniotic sac cavity

Question 48

formed by an extension of the hypoblast, holds insignificant amount of yolk but the digestive tube forms from part of it; tissue around the ylok sac gives rise to the earliest blood cells and blood vessels

Answer 48

yolk sac

Question 49

embryo grows from a two-layered disk to a three-layered disc during week 3; forms the three primary germ layers (ectoderm, mesoderm, and endoderm), the layers from which all body tissues develop

Answer 49

gastrulation

Question 50

raised groove appears on the dorsal surface of the eiblast days 14-15; epiblast cells migrate inward at this streak

Answer 50

primitive streak

Question 51

the first cells that migrate through the primative streak displace the cells of the underlying hypoblast to become the endoderm (day 14-15)

Answer 51

endoderm

Question 52

(starting on day 16) the ingressing (through primitive streak) epiblast cells form a new layer between epiblast and endoderm, the mesoderm

Answer 52

mesoderm

Question 53

"the epiblast cells that remain on the embryo's dorsal surface make up the ectoderm"

Answer 53

ectoderm

Question 54

or epithelia, sheets of tightly joined cells

Answer 54

epithelial tissues

Question 55

"""middle fluid"", any embryonic tissue with star-shaped cells that do not attach to one another"

Answer 55

mescenchyme tissue

Question 56

at one end of the primitive streak; cells go to form the notochord

Answer 56

primitive node

Question 57

defines the body axis and is the site of the future vertebral column (appears on day 16, and by day 18 it reaches the future head region)

Answer 57

notochord

Question 58

the forming of the spinal cord and brain

Answer 58

neurulation

Question 59

the ability of one group of cells to influence the developmental direction of other cells

Answer 59

induction

Question 60

develops into the digestive tube and respiratory structures

Answer 60

primitive gut

Question 61

the first rudiments of the limbs appear around day 28

Answer 61

limb buds

Question 62

one that occurs before 38 weeks after conception

Answer 62

premature births