Embryo Flashcards
pharyngeal arches: which parts are muscles, arteries, bone, and CT derived from?
muscles, arteries: somitomeric mesoderm
bone, CT: neural crest cells
what are the pharyngeal pouches?
evaginations of endoderm lining foregut
what are the pharyngeal grooves?
invaginations of ectoderm b/w each arch
which nerve is associated with each arch?
arch 1: trigeminal (5) arch 2: facial (7) arch 3: glossopharyngeal (9) arch 4: vagus (10) - superior laryngeal arch 6: vagus (10) - recurrent laryngeal
what is derived from arch 1? (5 muscles/groups of muscles, 8 bones, 1 ligament, 1 cartilage)
- muscles of mastication
- mylohyoid
- anterior digastric
- tensor veli palatini
- tensor tympani
- maxilla
- mandible
- incus
- malleus
- zygomatic
- squamous part of temporal
- palatine
- vomer
- sphenomandibular ligament
- Meckel’s cartilage
what is derived from arch 2? (4 muscles/groups, 3 bones, 1 ligament, 1 cartilage)
- facial expression muscles
- posterior digastric
- stylohyoid
- stapedius
- stapes
- styloid process
- stylohyoid ligament
- lesser horn/upper body of hyoid
- Reichert’s cartilage
what is derived from arch 3? (1 muscle, 2 vessels, 1 bone)
- stylopharyngeus
- common carotid aa.
- internal carotid aa.
- greater horn/lower body of hyoid
what is derived from arch 4? (4 muscles/ groups, 1 cartilage, 2 vessels)
- soft palate muscles (except tensor veli palatini)
- pharynx muscles (except stylopharyngeus)
- cricothyroid
- cricopharyngeus
- laryngeal cartilages
- R subclavian a.
- arch of aorta
what is derived from arch 6? (2 muscles/groups, 1 cartilage, 2 vessels)
- intrinsic larynx muscles (except cricothyroid)
- upper esophageal muscles
- laryngeal cartilages
- pulmonary aa.
- ductus arteriosus
what is derived from pouch 1?
- epithelial lining of auditory tube and middle ear cavity
- mastoid air cells
what is derived from pouch 2?
epithelial lining palatine tonsil crypts
what is derived from pouch 3?
- inferior parathyroid gland
- thymus
what is derived from pouch 4?
- superior parathyroid gland
- ultimobranchial body
what is derived from groove 1?
epithelial lining of external auditory meatus
what is derived from grooves 2,3,4?
obliterated
what is derived from membrane 1?
tympanic membrane
what is derived from membranes 2,3,4?
obliterated
embryonic origin of thyroid
endoderm - thyroid diverticulum
embryonic origin of tongue?
- ant 2/3: median tongue bud + 2 distal tongue buds (associated w/ arch 1)
- post 1/3: copula + hypobranchial eminence (associated w/ arches 2,3,4)
embryonic origin of face
from 3 swellings:
- frontonasal prominence
- maxillary prominence (arch 1)
- mandibular prominence (arch 1)
embryonic origin of mouth
stomodeum (ectoderm) + cephalic end of foregut (endoderm) - these meet at oropharyngeal membrane
embryonic origin of olfactory epithelium
thickening of ectoderm of nasal placode in roof of each nasal cavity
which epithelium comes from ectoderm?
- oral part of tongue
- hard palate
- sides of mouth
- lips
- parotid gland + ducts
- Rathke’s pouch
- enamel
which epithelium comes from endoderm?
- pharyngeal part of tongue
- floor of mouth
- palatoglossal fold
- palatopharyngeal fold
- soft palate
- sublingual gland + duct
- submandibular gland + duct
