Chapter 3 Terms

Question 1

The name given to the organism for approximately the first two months after fertilization

Answer 1

embryo

Question 2

By the end of the second month the embryo is now called a

Answer 2

fetus

Question 3

the prenatal period of development

Answer 3

gestation

Question 4

What happens during the first trimester

Answer 4

the embryo develops cell layers that are precursors to organ systems.

Question 5

What happens during the second trimester

Answer 5

growth, length, and mass gain and the appearance of functional organ system

Question 6

What happens during the third trimester

Answer 6

all organs prepare or are functional

Question 7

The specialization of cells in the developing fetus and migration of those cells to produce form and function

Answer 7

morphogenesis

Question 8

occurs when the spermatozoon and ovum join to produce a zygote

Answer 8

fertilization

Question 9

when sperm increase mobility

Answer 9

capacitation

Question 10

Layers of the follicular cells still encase the ovulated oocyte and now constitute a layer called

Answer 10

corona radiata

Question 11

sexual reproduction involving the fusion of two different gametes to form a zygote.

Answer 11

amphimixis.

Question 12

division that results in 2 cells

Answer 12

cleavage

Question 13

each cell after division is called a

Answer 13

blastomere

Question 14

an organized blastomere into a solid ball of identical cells

Answer 14

morula

Question 15

Around day 6 the morula has entered the uterus and changes into a hollow ball ofr cells

Answer 15

blastocyst

Question 16

the internal cavity in a blastocyst

Answer 16

blastocoele

Question 17

cells on the outside of the blastocyst that burrow into the uterine lining and form the placenta

Answer 17

trophoblast

Question 18

cells clustered in the blastocoele

Answer 18

inner cell mass

Question 19

begins on day 7 or 8 when the blastocyst touches the spongy uterine lining.

Answer 19

implantation

Question 20

When the cell membrane of the trophoblast cell disolves and the cells mass together as as cytoplasmic layer of multiple nuclei called

Answer 20

syncytial trophoblast

Question 21

space created in the endometrium from eroding villi

Answer 21

lacunae

Question 22

on the 9th or 10th dat the icm moves to the next layer of the cellular trophoblast this forms what cavity

Answer 22

amniotic cavity

Question 23

the inner cell mass is organized into a

Answer 23

blastodisc

Question 24

the 2 layers of the blastodisc

Answer 24

the superficial epiblast and the deep blastocoele facing hypoblast

Question 25

cells migrate in the process of (blank) to form primative streak

Answer 25

gastrulation

Question 26

the medial plane of the blastodisc is called

Answer 26

the primitive streak

Question 27

what does the epiblast become

Answer 27

ectoderm

Question 28

what does the hypoblast become

Answer 28

endoderm

Question 29

cells between endo and ectoderm

Answer 29

mesoderm

Question 30

What are the meso, ecto, and endo derm called

Answer 30

the germ layers

Question 31

Forms the nervous system, skin, nails ,hair.

Answer 31

ectoderm

Question 32

contributes to the development of the skeletal and muscular system

Answer 32

mesoderm

Question 33

forms part of the lining of the respiratory and digestive system

Answer 33

endoderm

Question 34

embryonic precoursors of skeletal muscles

Answer 34

somites

Question 35

the first membrane to appear after the 10th day.

Answer 35

yolk sac

Question 36

membrane that lines the inner surface of the amniotic cavity "water bag"

Answer 36

amnion

Question 37

forms part of the embryonic urinary bladder and forms some of body stalk

Answer 37

allantois

Question 38

tissue between embryo and developing chorion

Answer 38

body stalk

Question 39

outer extraembryonic membrane

Answer 39

chorion

Question 40

area of endometrium in contact with placenta

Answer 40

decidua basalis

Question 41

The rest of the endometrium where villi is absent isolates the embryo from the uterine cavity

Answer 41

decidua capsularis

Question 42

the endromitruim on othe wall opposite the embryo is called

Answer 42

decidua parietalis

Question 43

birth

Answer 43

parturition

Question 44

The embryonic period of prenatal development is the first ________ weeks.

Answer 44

8

Question 45

The splanchnic mesoderm forms next to this layer.

Answer 45

endoderm

Question 46

The epiblast develops a primitive streak during days 14-15, the initial cells that ingress through the primitive streak become this germ layer.

Answer 46

endoderm

Question 47

Embryonic epiblast cells that remain on the surface of the trilaminar disc are ultimately called

Answer 47

ectoderm

Question 48

The ribs and vertebrae form from this primary germ layer.

Answer 48

mesoderm-somites

Question 49

Blood vessels and the heart arise from this primary germ layer.

Answer 49

mesoderm-lateral plate

Question 50

Division of cells in a zygote is called

Answer 50

cleavage

Question 51

somites differentiate into

Answer 51

myotomes

Question 52

conception occurs in the

Answer 52

lateral (upper) third of the uterine tube

Question 53

The embryonic layer that invades the lining of the uterus and forms the placenta is the

Answer 53

trophoblast

Question 54

Which of the following does not distinguish mesoderm from either endoderm or ectoderm? _____

Answer 54

It is derived from the epiblast.

Question 55

The term bilaminar disc refers to the ________ and ________ layers of the blastocyst (zygote).

Answer 55

epiblast; hypoblast

Question 56

The amniotic sac is derived from the epiblast, while the placenta develops from the

Answer 56

trophoblast

Question 57

The ability of one cell to influence the development of its neighboring cells is called

Answer 57

induction

Question 58

Limb buds emerge in the human embryo about

Answer 58

day 28

Question 59

. epidermis . mouth .cloaca/ anus

Answer 59

epidermal ectoderm

Question 60

-central nervous system . forebrain .midbrain .hindbrain .spinal cord

Answer 60

neural plate ectoderm

Question 61

. peripheral nervous system . melanocytes/chromophores .visceral skeleton

Answer 61

neural crest ectoderm

Question 62

i. Somite 1. Dermatome a. Dermis 2. Myotome a. Axial and Limb Muscles 3. Sclerotome a. Vertebral Column

Answer 62

a. mesoderm: Paraxial (Epimere)

Question 63

. kidney .urogenital ducts

Answer 63

b. Intermediate Mesoderm

Question 64

i. Somatic hypomere (mesodermal part of Somatopleure) 1. Fin/Limb Buds (and fins and limbs in adults) ii. Splanchnic hypomere (mesodermal part of Splanchnopleure) 1. Blood and Blood Vessels 2. Extra-embryonic Membranes

Answer 64

Lateral plate mesoderm

Question 65

mouth esophagus lungs

Answer 65

endoderm: foregut

Question 66

stomach liver pancreas intestines

Answer 66

endoderm: midgut

Question 67

bladder cloaca/anus

Answer 67

endoderm: hindgut