embryology Flashcards
where do pharyngeal (or branchial) arches develop?
in all vertebrates
what order do the pharyngeal (or brachial) arches develop?
from head to neck
begin to develop between week 4 and 5
Arch 1- day 22
arch 2+ 3- day 24
Arch 4+ 6- day 29
when do the pharyngeal (or brachial) arhes develop?
begin to develop between week 4 and 5
Arch 1- day 22
arch 2+ 3- day 24
Arch 4+ 6- day 29
what are the three components of the pharyngeal apparatus?
- core pharyngeal arch (mesenchymal tissue)
- external pharyngeal cleft (ectoderm)
- internal pharyngeal pouch (endoderm)
what separates the pharyngeal arches?
clefts and pouches
what do each pharyngeal arch consist of?
- core of mesenchyme derived from paraxial and lateral plate mesoderm
- neural crest cells
- cranial nerve compartment
- artery (aortic arch arteries)
what does the musculature in ENT derive from?
-core of mesenchyme derived from paraxial and lateral plate mesoderm
what does smooth muscle and connective tissue in ENT derive from?
neural crest cells
what processes are part of the 1st arch?
- maxillary process
- mandibular process
what does the maxillary process (cranial portion) or the 1st arch go on to form?
- maxilla
- zygomatic
what does the mandibular process (caudal portion) or the 1st arch go on to form?
- Meckel’s cartilage
- incus and malleus (ear ossicles)
- mandible
- squamous portion of temporal bone
what is the cartilage within the 2nd cartilage called?
Reichert’s cartilage
what does the 2nd arch go on to form?
- stapes
- styloid process of temporal bone
- stylohyoid ligament
- lesser horn of hyoid
- upper part of hyoid
what does the 3rd arch go on to form?
- greater horn of hyoid bone
- lower part of hyoid bone
what do the 4th and 6th arches go on to form?
-laryngeal cartilages
what nerve supplies any structure made from the 1st arch?
Trigeminal nerve CN V
what nerve supplies any structure made from the 2nd arch?
Facial nerve (CNVII)
what nerve supplies any structure made from the 3rd arch?
Glossopharyngeal nerve (CNIX)
what nerve supplies any structure made from the 4th and 6th arch?
Vagus nerve (CN X)
where do all the muscles by CNV (trigeminal nerve) come from?
1st arch
which is the only motor component of trigeminal nerve?
V3 mandibular nerve
where do all the muscles supplied by CNVII (facial nerve) come from?
2nd arch
what are the muscles supplied by Trigeminal nerve CNV3?
- muscles of mastications
- tensor veli palatini
- tensor tympani
- mylohyoid
- anterior belly of digastric
what muscles are supplied by facial nerve CNVII?
- muscles of facial expression
- posterior belly of digastric
- stylohyoid
- stapedius
- auricular muscles
