Term
| When does the face begin to form, and when is it completed? |
|
Definition
|
|
Term
| What layers of the embryo are involved in facial development? |
|
Definition
| Ectoderm, Mesoderm, Endoderm |
|
|
Term
|
Definition
| fusion of swellingsor tissues on the same surface of an embryo. Cleft groove seperates but is taken over by messenchyme and a smooth surface is created. |
|
|
Term
| What is oral epithelium and to what does it give rise to? |
|
Definition
| Lines the oral cavity derived from ectoderm and gives rise to teeth |
|
|
Term
Oropharyngeal membrane
seperates what? |
|
Definition
| consists of ectoderm and endoderm. Seperates stomodeum from primitive pharynx. |
|
|
Term
| What is the term for primitive mouth? What is its lining? |
|
Definition
| Stomodeum, Oral Epithelium |
|
|
Term
| What is Primitive Pharynx? |
|
Definition
| cranial portion of the foregut, the begining of future digestive tract |
|
|
Term
| What are the mandibular processes and how do they form portions of the lower face? |
|
Definition
| core of messenchyme (formed in part by neural crest cells), outer ectoderm and endoderm inside. Paired mandibular processes fuse at midline to form mandibular arch |
|
|
Term
| What is the first branchial arch and meckels cartilage? |
|
Definition
| Mandibular arch,the cartilage that forms on each side of the arch is meckels cartilage and is removed over time. |
|
|
Term
| What is the frontonasal process and to what portion of the face does it give rise to? |
|
Definition
| buldge of tissue in upper facial area at cephalic end of embryo cranial boundry of stomodeum. Upper face, forhead, bridge of nose, primary palate, nasal septum |
|
|
Term
| Define Placodes, and describe the location of the lens, otic and nasl placodes |
|
Definition
| Rounded areas of specialized, thickened ectoderm. 1. side of the frontonasal process - future eyes 2. Laterally posterior - forms middle ear. 3. superior to stomodeum - olfactory cells for smell. |
|
|
Term
| Describe the further development of the nasal placodes and there relationship to the oronasal membrane. |
|
Definition
| form a depression in the center of each placode, nasal pits form which later develop into nostrils. nasal sacs develop and internally and are seperated from stomodeum by oronasal membrane. Oronasal membrane will go away leaving nasal and oral cavity in communication |
|
|
Term
| Describe the medial and lateral nasal processes on an embryo |
|
Definition
| middle portion and lateral portion between the nasal pits. Will form middle of nose from root to apex. |
|
|
Term
| What is the intermaxillary segment? To what does it give rise to? |
|
Definition
| medial nasal process that gre inferiorly. gives rise to maxillary incisor teeth, primary palate, nasal septum |
|
|
Term
| What happens to mandibular arch during fourth week. To what does this new process give rise to? |
|
Definition
| adjacent swelling from mandibular process grows out and becomes the maxillary process. Maxillary process forms future midface upper lip, cheeks, secondary palate |
|
|
Term
| Describe the embryological development of the upper lip. |
|
Definition
| 4th week. each maxillary process fuses with each medial nasal process as a result of underlying messenchyme. |
|
|
Term
| What occurs wit failure of fusion during the development of the upper lip and what is its ramifications orally? |
|
Definition
| Cleft Lip. Failure of messenchyme to grow beneathe the ectoderm. Speech development, appearance, oronasal infection. |
|
|
Term
| How does primitive pharynx develop? |
|
Definition
| the beginings of the embryos hollow tube are derived from the anterior portion of the foregut. |
|
|
Term
| What is the brachial apparatus? |
|
Definition
| consists of branchial arches, branchial grooves and membranes, and pharyngeal pouches. |
|
|
Term
| Name Arch and what it gives rise to. |
|
Definition
Mandibular arch - 1st - messenchyme (neural crest and ectoderm/endoderm)Meckels cartilage - Lower face, mandible.
Hyoid Arch - 2nd - reicherts cartilage - middle ear, temporal bone, hyoid bone - 7th cranial nerve
3rd - formation of portions of hyoid and 4th brachial arches - Tongue. 4th and 6th arch - laryngeal cartilages - muscles of larynx and pharynx. 9-10th cranial nerve
|
|
|
Term
| what is a branchial arch? |
|
Definition
| u shaped bar with messenchyme core formed by neural crest cells that migrate to the neck region. |
|
|
Term
| What are branchial grooves? |
|
Definition
| external grooves noted on each side of the embryo. 1st groove forms external auditory meatus. It is eventually obliterated leaving smooth neck contour. |
|
|
Term
| Name the tissues associated with the pharyngeal pouches? |
|
Definition
1st pouch - tympanic membrane, tympanic cavity, auditory tube, mastoid antrum
2nd pouch - crypts and lymphatic nodules of the palatine tonsils
3rd and 4th - Parathyroid and thymus glands |
|
|
Term
| What are cervical cysts? and how can they be present? |
|
Definition
| Left over branchial grooves that did not disappear. can remain free in neck or inferior to mandible along sternocleidomastoid muscle. Produce slowly enlarging painless swelling. |
|
|
