Chapter 18 Flashcards
Development of the Orofacial Complex
How long is the period of ovum
2 weeks of gestation
How long is the period of embryo
3-8 weeks of gestation
How long is the period of fetus
9-36 weeks
What are the 3 germ layers of the body
Endoderm, Mesoderm, Ectoderm
Describe the Endoderm layer
respiratory epithelium, digestive system, liver, pancreas
Describe the Mesoderm layer
muscle, blood vessel, lymphatics, connective tissue, bone and cartilage
Describe the Ectoderm layer
oral cavity, teeth, nails, skin, eye tissue, nervous system
Early stages of the face begin developing at………
3 weeks
From head to tail the embryo measures…..
3-4 mm
From a lateral view what 3 features are present?
umbilical cord, heart bulge, pharyngeal arch
The lower end of the tube is the development of the…..
digestive tract
What does the foregut form?
The digestive tract from the throat region of the duodenum
What does the midgut form?
the rest of the small intestine, cecum, ascending colon, most of transverse colon
What does the hindgut form?
the descending colon, sigmoid colon to the rectum of the large intestine
What does the stomodeum form?
The oral cavity and the oral pharynx
What separates the stomodeum from the primitive pharynx?
the buccopharyngeal membrane
Where the foregut and stomodeum share a wall
buccopharyngeal membrane
What happens at the 4 1/2 week mark with the buccopharyngeal membrane?
It connects the oral cavity to the digestive tract
There are __ pharyngeal arches. They are __ shaped
6, U
Pharyngeal arches surround the _____
Form between the ____ and the _____
foregut of the embryo,
brain and the heart
What cells form the pharyngeal arches
ectoderm, mesoderm, endoderm
What is the 1st pharyngeal arch called?
mandibular arch
The 1st pharyngeal arch gives rise to the _____ and ______
mandible and the maxillary process
In the 1st arch, what does the mandibular process form?
mandible, lower lip, anterior of tongue
In the 1st arch, what does the maxillary process form?
The maxilla (upper jaw), zygomatic bone (cheek), palatine bone, upper lip
What cartilage is the 1st arch associated with?
Meckel cartilage & muscle of mastication
In the 1st arch, what does the cleft/groove give rise to?
the external auditory meatus
In the 1st arch, what does the pouch give rise to?
auditory tube, tympanic cavity, middle ear
What nerve is associated with the 1st arch
trigeminal nerve
What is another name for the 2nd arch?
hyoid arch
What does the 2nd arch form?
hyoid bone, styloid process of the temporal bone, assists in forming front and side of the neck.
What cartilage is the 2nd arch associated with?
Reichart’s Cartilage
Does the 2nd arch cleft give rise to anything?
NO
In the 2nd arch, what does the pouch give rise to?
palatine tonsils
What nerve is the 2nd arch associated with?
Facial nerve and muscle of facial expression
What does the 3rd arch form
hyoid bone and styloid process of temporal bone
in the 3rd arch, what does the pouch give rise to?
Endocrine gland, parathyroid gland, thymus, stylopharyngeus muscle
What nerve is associated with the 3rd arch
glossopharyngeal nerve
Does the 3rd arch have a cartilage derivative and a cleft groove?
NO
What cartilage is the 4th and 6th pharyngeal arch associated with?
epiglottic, arytenoid, thyroid, and cricoid cartilage
In the 4th/6th pouch, what does the pouch give rise to?
internal parathyroid gland
What nerve is associated with the 4th/6th arch?
vagus nerve
Muscles of the 4th/6th arch
Larynx, Levator palatine, and constrictors of the pharynx
What arch forms the anterior of the tongue?
1st
What arch forms the posterior body of the tongue
2nd and 3rd
What structures make up the tongue?
tuberculum impar, two lateral lingual swellings and copula
How does the tongue separate from the floor of the mouth?
down growth of ectoderm around its periphery
What is the function of the lingual sulcus?
Gives tongue mobility
Depression located in the middle of the tongue
foramen cecum
Lingual thyroid
forms into a big red lump if the thyroid gland does not grow downward
What does the foramen cecum give rise to?
thyroid gland
Rathke’s pouch
upward growth of tissue that breaks loose from the oral cavity. Comes into contact with downward growth of the brain.
Where is the rathke’s pouch located?
palate region
The rathke pouch also forms what?
the anterior part of the pituitary gland (pars intermedia)
What is the pituary gland
forms the hormones
When does the face usually development
4-8 weeks
What part of the face is the first to form
mandible
what does frontonasal prominence form? What bone does it use?
forms the bridge of the nose and the forehead. Uses frontal and nasal bone
What does the maxillary prominence form? What bones does it use
forms the upper cheek regions and the upper lip. maxilla, zygomatic bone, secondary palate.
What does the mandibular prominence form and fuse?
mandible (lip, cheek, and chin)
What does the lateral nasal prominence form
alae of the nose
What does the medial nasal prominence fuse and form?
intermaxillary segment
When does palatal development begin and end
begins at the end of the 6th week and completes by the 12th week
The palate develops from 2 primordia
primary and secondary palate
When does the cleft lip develop
3rd-6th week (period of embryo)
Definition of cleft lip
lack of connective tissue migration between maxillary process and fuses the medial nasal process.
