EMBRYOLOGY TIMELINE

EMBRYOLOGY TIMELINE

pre-implantation period

"period of unattached conceptus"

{week one}

2) blastocyst forms

...and eventually start having the cutest little teeth:)

1) ovum and sperm unite

to create zygote

And from all that...the true miracle of life.

Cutest little babies started as a microscopic sperm and ovum:)

3) blastocyst implants

into endometrial lining...

p.s. isn't that just the sweetest smile you've ever seen?!?

which brings us to the second stage of development

{week 3}

cont...

-Formation of cephalic and caudal ends as well as stomodeum

-Cephalic=oropharyngeal membrane

-Caudal=cloacal membrane

-CNS begins development

-Neural plate

-Neural groove

-Neural fold

-Neural tube [furthered in week 4]

{week 2}

• Blastocyst forms embryonic cell layer
• Embryonic disc is developed

• Placenta forms from each layer of the embryonic disc

{week 3}

1) bilaminar disk is dvidided

by primitive streak

2) MESENCHYME: new embryonic layer created...

which becomes muscles, vessels, etc..

{week 4}

3) Ectoderm becomes epidermis [skin]

and nervous system

-mandibular arch forms

-neural tube finishes formation

-embryonic folding occurs...which then becomes the foregut, midgut, and hindgut

-primitive face begins development

-tongue begins development

{week 5}

primary palate development

-the 2 medial nasal processes fuse

which gives rise to the primary palate

-the primary palate forms the

anterior 1/3 of the hard palate

-primary palate includes maxillary incisors

-tongue continues to develop

{week 6}

secondary palate formation

-maxillary processes give rise to

lateral palatine processes

-processes grow medially towards each

other to form the median palatine raphe

{week 7}

-Initiation of teeth begins

-formation of primary dental lamina

-induction of teeth continue

1. ectoderm lines stomodeum

2. dentin, pulp, periodontium from mesenchyme

3. embryologic tissues are separated by

basement membrane

-tongue continues devlopment

-tongue and palate continue formation

EMBRYONIC PERIOD

[WEEK 2 THROUGH WEEK 8]

{week 8}

end of embryonic period

-tongue finishes development--->

tuberculum impar, lateral lingual swellings, and copula have merged together

-sulcus terminalis marks the

anterior and posterior portions

-tongue moves anterior in mouth

-intrinsic muscles of the tongue complete

from the four branchial arches

-papillae form--->

circumvallate...foliate...fungiform

-bud stage of teeth--->

dental lamina is further invaginated

into mesenchyme

-proliferation: ectoderm and mesenchyme grow

-primary dentition form

2nd TRIMESTER to BIRTH

{week 40}

-get ready to rumble!!! :)

FETAL PERIOD

{week 25}

-capillaries are forming underneath skin

-lungs developing surfactant

-growing hair

-fun fact

{week 30}

Week 25 Pregnancy Tip: Dental Health

"Want to keep your baby safely inside you until term? Put your dental floss where your mouth is. Surprisingly, research links good dental health and oral hygiene with longer pregnancies. Sounds crazy — doesn't it? Crazy, but true. Something as simple as brushing your teeth at least twice a day and flossing regularly can reduce the risk of gingivitis — a common condition in which your gums become inflamed, red, and even begin to bleed. Untreated gingivitis (that's where the regular dental checkups come in) can progress to periodontitis — a more serious infection of the teeth — which has been linked to premature birth and even an increased risk of preeclampsia. Keep on top of your teeth, and that old (untrue) wives' tale — the one that claims that a woman loses a tooth with each pregnancy — can finally be put to rest"

-What to Expect When you're expecting

-brain is growing daily

-size of cabbage :)

{week 35}

-fully developed kidneys

-rapidly increasing brain

development

-size of honeydew melon :)

FINAL DEVELOPMENT AND MATURATION

THREE MAIN STAGES

OF DEVELOPMENT :)

{WEEK 9}

-nasal septum begins development

-cap stage of teeth

-ectoderm stretches to form a "cap" to create enamel organ

-differentiation and morphogenesis occur

-dental papilla will form future dentin and pulp

-future site of dentoenamel junction exists

-dental sac covers and protects teeth

{week 10}

-nasal septum growth

-filiform papilla form

-cap stage of teeth continue

-successional dental lamina develops...which eventually becomes succedaneous teeth [permanent teeth]

{week 11}

-palate formation continues

-bell stage of tooth development

-enamel organ grows and surrounds dental papilla

-cells differentiate--->

stage 3:

fetal period

{week 15}

outer enamel epithelium

stellate reticulum

stratum intermedium

inner enamel epithelium

-the IEE is what forms the enamel

-amniotic fluid flowing thru nasal and respiratory tracts

-can wiggle fingers and kick legs

-baby is size of an orange :)

-cells of dental papilla differentiate into

inner cells and outer cells

inner cells=dental pulp

outer cells =dentin

{week 20}

-able to swallow

-size of a banana :)

stage 2:

embryonic period

stage 1:

pre-implantation period

{week 12}

-bell stage of tooth development continues

-palate completes development

-oral and nasal cavities are completely separate