1 Embryo

Front 1

Three tasks in early phase development

Back 1

1. Increase the number of cells through cell division

2. Increase the number of cell types of differentiation

3. Generate polarity to allow the establishment of the future body axis

Front 2

Question 1

Back 2

How can an embryo generate different cell types when it starts out as a single cell

Front 3

Question 2

Back 3

Periods and degrees of sensitivity of embryonic organs to teratogens

Front 4

Common Teratogens

Back 4

Alcohol

Retinoic acid

Thalidomide

Dietary deficiencies and malnutrition

Front 5

Congenital or External development

Back 5

Congenital - genetic changes

External - caused by changes in environment

Front 6

Question 3

Back 6

The same set of genes are implicated in embryogenisis and some cancers

Front 7

Zygote

Back 7

Fertilized egg

Front 8

Embryo

Back 8

Developing organism from fertilization through the formation of differentiated tissues

Front 9

Embryology

Back 9

Science which explores embryogenisis (stages: fertilization, cleavage, gastrulation, organogenisis and histogenisis)

Front 10

Developmental Biology

Back 10

Studies the life cycle from embryogenisis to postembryonic development to adulthood

Front 11

Ontogeny

Back 11

Life cycle of an organism from conception to death

Front 12

Histogenisis

Back 12

The formation of tissues from undifferentiated cells

Front 13

Organogenesis

Back 13

The process in which endoderm, ectoderm, and mesoderm form the bodies organs

Front 14

Morphogenesis

Back 14

The process of an organism developing into it's shape

Happens because of cell division, cell growth, changes in membrane composition and secreted products, changes in cell shape, movement, migration and death.

Front 15

Two major developmental biology questions

Back 15

1. How does adult organism develop from one cell

2. How does adult organism produce anouther organism

Front 16

Steps of developmental biology

Back 16

1. Cell differentiation

2. Morphogenesis

3. Growth

4. Reproduction

5. Evolution

6. Environmental integration

Front 17

Comparative embryology

Back 17

Embryonic similarities between different groups of animals

Front 18

Homologous structures

Back 18

Organs which are similar because they derive from a common ancestral structure

Front 19

Analogous structures

Back 19

Organs which are similar because they perform a similar function

Front 20

Embryogenesis Steps

Back 20

1. Fertilization

2. Cleavage

3. Gastrulation

4. Organogenesis

5. Histogenesis

Front 21

Fertilization

Back 21

Union of sperm and egg

Triggers numerous metabolic reactions that influence further development (Ca+, protein synthesis)

Front 22

Egg

Back 22

Large cell, lots of nutrients in the yolk

Two poles; animal (close to nucleus) and vegetal (yolk)

Front 23

Sperm

Back 23

Has to find and fertilize egg, condensed nucleus and flagellum

Front 24

Development Regulation Enforced by:

Back 24

Cytoplasmic maternal determinants & genome of zygote

Front 25

Cleavage

Back 25

Series of mitotic divisions

Blastomeres get smaller to form blastula

Blastula will become hollow with a blastocoel filled with fluid

Majority of cells now have a predictable fate

Front 26

Pattern of embryonic cleavage is determined by

Back 26

Amount of yolk in egg cytoplasm

Distribution of yolk in egg cytoplasm

Front 27

Blastomeres

Back 27

Cells produced by series of mitotic divisions

Front 28

Fate Map

Back 28

Early gastrula stage

More pigment on animal side

Dorsal lip

Dye cells in blastula and watch development

Front 29

Back 29

Front 30

Commitment to cell fate

Back 30

1. Specification - cells fate is reversible, can be affected by environment changes

2. Determination - irreversible, can not be changed by environment, non visible

3. Differentiation - absolutely irreversible, change in biochemistry, structure, appearance, function

Front 31

Cell potency and fate

Back 31

Totipotent - can give rise to a complete individual

Pluripotent - can form more structures than their original fate

Multipotent - similar to pluripotent but fewer structures

Front 32

Epithelial Cells

Back 32

Sheets connected by junctional complexes that act as a barrier

Move in harmony

Clear polar character from one side to anouther

Basal lamina is the foundation that contacts only one surface of the cell

Front 33

Mesenchymal Cells

Back 33

Loosely organized and attached

Can migrate as individual cells

Adhere in 3D clumps

Basal lamina may surround the cells

Epithelial cells can become mesenchymal

Front 34

Cell to cell interactions

Back 34

Induction - one cell or group of cells change the behavior of anouther cell or group of cells

Competence - ability of cells to respond to inductive signal

Signal transduction - different pathways to obtain induction or competence capabilities

Front 35

Gastrulation

Back 35

Series of complex morphogenic movements and activities to form the gastrula

Proliferating cells migrate, rearrange, bend, fold and spread

Front 36

Back 36

Front 37

Back 37

Epiboly

Intercalation

Convergent extension

Front 38

Three germ layers

Back 38

Ectoderm

Endoderm

Mesoderm

Front 39

Ectoderm

Back 39

Forms the outer layer of skin and nervous system

Front 40

Endoderm

Back 40

Forms the inner lining of the digestive tract and its appendages

Front 41

Mesoderm

Back 41

Forms bone and other skeletal structures, muscle, heart, blood vessels, blood cells, kidneys, reproductive organs

Front 42

Back 42

Front 43

Organogenesis

Back 43

Further movements of germ layers, most cells reach final destination

Neurulation - form rudiment CNS

Ectoderm forms neural plate --> neural tube

Endoderm forms gut rudiment - archenteron

Mesoderm - backbone, dorsal muscle, kidneys, heart

Front 44

Histogenesis

Back 44

Happens during organogenesis

Final cell differentiation

Front 45

Ectoderm forms

Back 45

Outer surface, CNS, Neural crest

Front 46

Mesoderm forms

Back 46

Dorsal, paraxial, intermediate, lateral, head

Front 47

Endoderm forms

Back 47

Digestive tube, pharynx, respiratory tube

Front 48

Germ cells form

Back 48

Male sperm and female egg

Front 49

Postembryonic development begins:

Back 49

After hatching for animals

9th week till birth in humans

Front 50

Direct development

Back 50

Developing animal looks like miniature adult

Fetus, juvenile

Front 51

Indirect development

Back 51

Developing animal larva goes through series for events and changes (metamorphosis)

Tadpoles - frogs

Caterpillars - moths

Butterflies/ maggots of flies

Front 52

Adulthood

Back 52

Production of mature sperm and egg (gametogenesis)

Ends with death

Mating and parenting

Maintaining body

Senescence - process of deterioration