Exam 2

Question 1

Define ontogenesis:

Answer 1

the growth of an organism from its early stages to maturity

Question 2

define odontogenesis:

Answer 2

the process of tooth formation

Question 3

define morphogenesis:

Answer 3

the process of size and shape formation

Question 4

define growth:

Answer 4

the proliferation of new cells

Question 5

define development:

Answer 5

the changing of cells into specific tissue types

Question 6

define tissue:

Answer 6

a group of cells with specialized functions

Question 7

define organ:

Answer 7

a structure comprised of 2 or more tissues

Question 8

define germ layer:

Answer 8

a group of embryonic cells that interact with each other to contribute to the formation of different organs and tissues

Question 9

What are the components of the germ layer?

Answer 9

1. endoderm
2. mesoderm
3. ectoderm
4. neural crest cells
5. ectomesenchyme cells

Question 10

define endoderm:

Answer 10

the inner germ layer that differentiates into the lining of the tracts and organs

Question 11

define mesoderm:

Answer 11

the middle germ layer that differentiates into connective tissues

Question 12

define ectoderm:

Answer 12

the outer germ layer that differentiates into epithelial tissue and nervous tissue

Question 13

when the ectoderm differentiates into epithelial tissue what part of the tooth does it eventually produce?

Answer 13

the ameloblasts

Question 14

define neural crest cells:

Answer 14

cells from the ectoderm that contributes to the smooth muscle, peripheral nervous system

Question 15

what do neural crest cells occasionally induce into?

Answer 15

ectomesenchyme cells

Question 16

What do cells from the ectoderm eventually become in reference to the germ layer?

Answer 16

neural crest cells

Question 17

define ectomesenchyme cells:

Answer 17

cells that produce the dentin, pulp, cementum, periodontal ligament, gingiva, and the alveolar bone

Question 18

define induction:

Answer 18

a group of cells will direct the development of a second group of cells

Question 19

define diferentiation:

Answer 19

when the second group of cells from induction changes from one type to another

Question 20

True or False: In the process of odontogenesis tissues will always affect each other unidirectionally

Answer 20

False

Question 21

In the process of odontogenesis how is induction carried out?

Answer 21

through molecular signaling (i.e. enamel knot)

Question 22

true or false: in the process of odontogenesis induction includes the process of differentiation

Answer 22

true

Question 23

define epithelium:

Answer 23

tissues on the outer layer from the ectoderm germ cells

Question 24

define mesenchyme:

Answer 24

connective tissue from the mesoderm germ cells

Question 25

True or false: The epithelium and mesenchyme have reciprocal molecular signaling

Answer 25

true

Question 26

what are some examples of what the signaling between the epithelium and mesenchyme form?

Answer 26

teeth, hair, feathers, breasts

Question 27

When does the fertilization of an egg occur and where does it usually happen?

Answer 27

it occurs when the sperm penetrates the outer ovum layer in the fallopian tube

Question 28

How is a zygote produced?

Answer 28

the combining of the nuclei of the male and female germ cells

Question 29

define morula:

Answer 29

a ball of cells

Question 30

what occurs at about 3-4 days after fertilization?

Answer 30

the zygote undergoes cell division producing a morula

Question 31

define blastocyst:

Answer 31

a group of cells that becomes an embryo

Question 32

what occurs at about 5-7 days after fertilization?

Answer 32

cell division continues and forms a blastocyst

Question 33

what occurs at about 7-10 days after fertilization?

Answer 33

implantation occurs as the blastocyst penetrates the inner layer

Question 34

When does the blastocyst phase occur?

Answer 34

at about 10-13 days after fertilization

Question 35

What occurs during the blastocyst phase?

Answer 35

inner mass cells begin to flatten and differentiate into the formation of the endoderm and ectoderm, while the amniotic cavity forms

Question 36

when does the gastrula phase begin?

Answer 36

at about 16 days after fertilization

Question 37

what occurs during the gastrula phase?

Answer 37

the cells migrate inward while further differentiation occurs causing the formation of the mesoderm between the endoderm and ectoderm

Question 38

when does the neurulation phase occur?

Answer 38

at about 30 days after fertilization

Question 39

what occurs during the neurulation phase?

Answer 39

three germ layers, mesoderm, ectoderm, and neural crest cells, develop into organs and associated tissues

Question 40

during the neurulation phase how is the mesoderm germ layer affected?

Answer 40

the cells in the mesoderm form a notochord and become a verbal column

Question 41

during the neurulation phase how is the ectoderm germ layer affected?

Answer 41

the ectoderm layer folds inward (pitches off -> neural tube -> spinal cord)

Question 42

during the neurulation phase how are the neural crest cells affected?

Answer 42

the cells differentiate after neural tube creatin a unique embryonic tissue in vertebrates

Question 43

true or false: the differentiation of neural crest cells during the neurulation phase is hugely important for the peripheral nervous system and teeth

Answer 43

true

Question 44

What two tissues does odontogenesis focus on?

Answer 44

Epithelium
Ectomesenchyme cells