General Embryology 1/12/17

Question 1

What is embryology?

Answer 1

-Study of prenatal development

Question 2

When does prenatal development occur?

Answer 2

Start with pregnancy until birth

Question 3

What two periods of prenatal development occur during the first trimester?

Answer 3

• Perimplantation

- Embryonic

Question 4

What period constitutes the last two trimesters?

Answer 4

-Fetal period

Question 5

Each craniofacial structure has a ____ the earliest indication of a tissue or an organ during prenatal development.

Answer 5

-Primordium (fore runner for structure)

Question 6

From the zygote what does mitosis lead to the formation of?

Answer 6

-blastocyst

Question 7

What does the blastocysts contain?

Answer 7

-a fluid filled vesicle that implants in the uterine wall

Question 8

The blastocyst will then give way to a disc and begin to differentiate into what?

Answer 8

3 distinct germ layers

Question 9

What are three ways that growth factors can work?

Answer 9

• Autocrine
• Paracrine
• Endocrine

Question 10

What are three changes that can be induced by growth factors?

Answer 10

• Proliferation
• Differentiation
• Apoptosis

Question 11

What is a critical growth factor in craniofacial development?

Answer 11

-Bone morphogenic protein (BMP)

Question 12

At gastrulation what happens with BMP?

Answer 12

-Switches between epidermal vs neural fate

Question 13

What is a Negative regulator of myogenesis? (makes bone instead of muscle)

Answer 13

BMP

Question 14

What type of genes code for transcription factors that make cells pattern into one tissue organ type or another?

Answer 14

-Homeobox genes

Question 15

What type of genes are involved in bodily segmentation during embryonic development?

Answer 15

-Homeobox genes

Question 16

What type of genes help regulate which end is going to be which?

Answer 16

-Homeobox genes

Question 17

What cell adhesion molecules are calcium dependent?

Answer 17

-Cadherins

Question 18

What cell adhesion molecules are calcium independent?

Answer 18

-CAM

Question 19

What molecules are responsible for specific cell aggregation and sorting?

Answer 19

-Cell adhesion molecules

Question 20

Nuerectoderm progenitors express what adhesion molecule?

Answer 20

-N-CAM

Question 21

Skin ectoderm progenitors express what adhesion molecule?

Answer 21

-L-CAM

Question 22

What is the first period of embryological development?

Answer 22

-Perimplantation period

Question 23

What does the perimplantation period occur?

Answer 23

-During the first week after conception

Question 24

To form a blastocyst what must occur?

Answer 24

-Cell division (mitosis)

Question 25

After fertilization, the zygote undergoes mitosis, or individual cell divsion or ______?

Answer 25

Cleavage

Question 26

After the initial cleavage of the zygote what is the solid ball of cells known as?

Answer 26

-Morula

Question 27

When the blastocyst stops and implants in the thickened uterine wall or endometrium it is known as what process?

Answer 27

-Implantation

Question 28

What invades the uterine wall that ultimately becomes the placenta?

Answer 28

-Trophoblast cells

Question 29

When does the embryonic period occur?

Answer 29

Beginning of week 2 to end of week 8

Question 30

During the embryonic period what are important spatial and temporal events called?

Answer 30

-Patterning

Question 31

When starts to form during the embryonic period?

Answer 31

- Pharyngeal arches - Somite development - Face development - Palate and tongue formation

Question 32

T/F | During the embryonic phase axial specification occurs.

Answer 32

True

Question 33

When does the development of dentition begin?

Answer 33

-Embryonic phase

Question 34

When one group of cells tells another groups of cell that are competent what to do is called what?

Answer 34

-Induction

Question 35

What is the term for cell division and increase in number and accumulation of cell products?

Answer 35

-Proliferation

Question 36

What is differentiation?

Answer 36

-Development of specific structures and or functions by individual cells or group of cells

Question 37

What is morphogenesis?

Answer 37

-Cell migration, interactions, and proliferations causing the development of specific structures

Question 38

What is gastrulation?

Answer 38

-Formation of the 3 germ layers

Question 39

What is the origin of the Ectoderm?

Answer 39

-Epiblast layer

Question 40

What is the origin of the Mesoderm?

Answer 40

-Migrating cells from epiblast

Question 41

What is the origin of the endoderm?

Answer 41

-Hypoblast layer

Question 42

What are the future systemic tissues from the ectoderm?

Answer 42

- Epidermis - Sensory epithelium of eyes - ears - nose - nervous system - neural crest - mammary and cutaneous glands

Question 43

What are future systemic tissues from the mesoderm?

Answer 43

- Dermis - Muscle - Bone - Lymphatics - Blood cells and bone marrow - cartilage - reproductive and excretory organs

Question 44

What are the future systemic tissues from the endoderm?

Answer 44

- Respiratory and digestive system linings | - Liver and pancreatic cells

Question 45

After the blastocyst implants the embryoblast differentiates into what two layers?

Answer 45

- Dorsal cells (epiblast) | - Ventral cells (hypoblast)

Question 46

The Epiblast layer (dorsal cells) reorganize to form what?

Answer 46

-amniotic cavity

Question 47

The ventral cells (hypoblast layer forms what?

Answer 47

-The roof of the secondary yolk sac

Question 48

The bilaminar germ disc layer that is superior and has high columnar cells is which layer?

Answer 48

-Epiblast

Question 49

The bilaminar germ disc layer that is inferior and has small cuboidal cells is what layer?

Answer 49

-Hypoblast

Question 50

After the formation of the bilaminar disk a structure called what forms?

Answer 50

-Primitive streak

Question 51

T/F | The primitive streak is the future bilateral symmetry along a rostral-caudal axis.

Answer 51

-True

Question 52

What layer folds to form the primitive streak?

Answer 52

-Epiblast

Question 53

What cells invaginate at the primitive mode forming the primitive pit?

Answer 53

-Ectodermal cells

Question 54

What cells actually form the true embryonic endoderm and mesoderm?

Answer 54

Mesoblast

Question 55

The notochord and mesoderm separate the ectoderm and endoderm everywhere except where?

Answer 55

- Prochordal plate | - Cecal plate

Question 56

The fold at the prochordal plate form what membrane?

Answer 56

-Oropharyngeal (buccopharyngeal)

Question 57

What layer cells give rise to tooth enamel?

Answer 57

-Ectodermal

Question 58

What oral structures are derived from mesodermal cells?

Answer 58

- Dentin - pulp - cementum - periodontal ligament (though all of these come from the neural crest)

Question 59

What three events occur after week 3 or gastrulation?

Answer 59

- Differentiation of nervous system - formation/migration of neural crest - Embryo folding

Question 60

The paraxial portion of the mesoderm is responsible for forming what?

Answer 60

- Cartilage | - segmented muscle

Question 61

The intermediate portion of the mesoderm is responsible for forming what?

Answer 61

- Kidneys | - Gonads

Question 62

The lateral plate of the mesoderm is responsible for forming what?

Answer 62

- Heart | - Gut

Question 63

What do differentiated mesoderm germ rise to?

Answer 63

-Somites

Question 64

What does the neural tube expand to form?

Answer 64

- Forebrain - midbrain - hindbrain

Question 65

What does the neural crest develop from?

Answer 65

-Neuroectoderm

Question 66

What disease occurs when there is a failure of neural crest cells to migrate to the facial region?

Answer 66

-Treacher Collins syndrome

Question 67

What is the term for the primitive mouth?

Answer 67

-Stomodeum

Question 68

What gives rise to the primitive pharynx?

Answer 68

-Foregut