Embryology Development Flashcards
When is the preimplantation period?
Week 1
When is the embryonic period?
Week 2 to 8
When is the fetal period?
Month 3-9
What are the 3 layers of the trilaminar disc?
Ectoderm (outer layer) , mesoderm, and endoderm (inter layer)
What do the Neural crest cells responsible for (there are 12)?
- ) Face
- ) Neck
- ) Oral tube
- ) Nervous System
- ) Pigment Cells
- ) CT proper
- ) Cartilage
- ) Bone
- )Pulp
- ) Dentin
- ) Cementum
- ) PDL
What dental structure does ectoderm give rise to?
Tooth Enamel
What dental structure does mesoderm give rise to?
Dentin, pulp, cementum, and PDL
What dental structure does endoderm give rise to?
No dental structures are from the endoderm
What is ectodermal dysplasia?
Abnormal development of ectodermal structures such as teeth, hair, skin, nails, sweat glands, eyes, and sometimes ears. “Little old men”
What does the ectoderm give rise to (8 items)?
Epidermis of the skin Hair and nails Nervous system Epithelium of oral cavity, nasal cavity, anal cavity Salivary, cutaneous, mammary, pituitary, adrenal glands Epithelium lining of paranasal sinuses Tooth enamel Special sensory epithelium (eyes, ears, nose)
What does the mesoderm give rise to (7 different areas)?
Dermis of the skin CT Cartilage, bone Lymphoid tissue and vessels Muscle Tissue (mastication, CNV) Blood and blood vessels, heart Dentin, pulp, cementum, and PDL Kidneys
What does the endoderm give rise to (7 different areas)?
Gastrointestinal tract Pharynx, larynx, Eustachian tubes Trachea, bronchi, lungs Urinary bladder, gallbladder, liver Thyroid, parathyroid, pancreas, thymus, prostate glands Vagina, urethra, and associated glands Epithelial lining of respiratory tract
What is the process of stomodeum formation?
The stomodeum shares a wall between the oropharyngeal membrane & foregut. The ectoderm gets a depression and is positioned between the frontonasal process and developing heart. Mandibular arch forms 1st.
When does the stomodeum form and when is it complete?
Week 3 to 4, Opens at 4.
Explain the origin of the nueral crests?
Comes from the ectoderm. Forms along with neural tube and migrates into the mesenchyme (embryonic CT) region (mesoderm) .
What does Nueral Crests have to do with the embryonic development of the Head and Neck?
They migrate to those areas and contribute to the formation of the head and neck.
What does the embryonic CT develop into?
fibroblasts, osteoblasts, and chrondroblasts.
What are the structures that arise from the branchial (pharyngeal) ARCH 1?
Mandibular Arch: Anterior 2/3 of tongue (body), lower lip, mandible teeth and tissues
Mesoderm-5th trigeminal nerve, muscles of mastication
Two maxillary and two mandibular processes: zygomatic bone, palatine bones, and upper jaw.
What are the structures that arise from the branchial (pharyngeal) ARCH 2?
Hyoid Arch: Posterior 1/3 of tongue
Innervated by Facial nerve #7
Mesoderm form muscles of facial expression, suprahyoid muscles
What cartilage is in branchial arch 1 and what does it do?
Meckel’s; disappears during development.
What cartilage is in branchial arch 2 and what does it do?
Rietchert only stays in hyoid, ear, and temporal bone. Most of it disappears.
What are the structures that arise from the branchial ARCH 3?
Nerve: IX glossopharyngeal
Posterior 1/3 of tongue, pharyngeal muscle
What are the structures that arise from the branchial ARCHES 4 to 6?
Nerves: IX glossopharyngeal and X vagus
Root of tongue and epiglottis