Embryology Flashcards
When does the development of the head and neck begin?
4th and 5th week
What is mesenchymal tissue?
Connective tissue
Where are the pharyngeal clefts?
Ectodermal surface of the pharyngeal arches
Where are the pharyngeal pouches?
Endodermal surface of the pharyngeal arches
What are the components of each pharyngeal arch?
Cranial nerve
Muscular component
Cartilaginous supporting element
Vascular component
What is the 1st pharyngeal arch comprised of?
Maxillary prominence (dorsal portion)
Mandibular prominence (ventral portion)
What cranial nerve is the 1st pharyngeal arch associated with?
Mandibular branch of trigeminal nerve (CNV)
What does the artery of the 1st arch become?
Maxillary artery (branch of ECA)
What muscles does the 1st pharyngeal arch give rise to?
Muscles of mastication
What is the fate of the 1st pharyngeal cartilage?
Mandible
Maxilla
Zygomatic bone
Part of temporal bone
What cranial nerve is the 2nd pharyngeal arch associated with?
Facial nerve (CNVII)
What 2 arteries are associated with the 2nd arch?
Stapedial artery (regresses before birth)
Hyoid artery
What muscles does the 2nd pharyngeal arch give rise to?
Muscles of facial expression
What is the fate of the 2nd pharyngeal cartilage?
Stapes
Styloid process
Stylohyoid ligament
Upper body and lesser horn of hyoid bone
What cranial nerve is the 3rd pharyngeal arch associated with?
Glossopharyngeal arch (CNIX)
What does the artery of the 3rd arch become?
Common carotid artery
Proximal portion of internal carotid artery
What muscle does the 3rd pharyngeal arch give rise to?
Stylopharyngeus
What is the fate of the 3rd pharyngeal cartilage?
Lower body and greater horn of hyoid bone
What cranial nerve is the 4th pharyngeal arch associated with?
Superior laryngeal branch of Vagus nerve (X)
What does the artery of the 4th arch become?
Right- subclavian artery
Left- aortic arch
What muscles does the 4th pharyngeal arch give rise to?
Muscles of larynx
What is the fate of the 4th pharyngeal cartilage?
Laryngeal cartilages:
Thyroid cartilage
Corniculate cartilage
Cuneiform cartilage
What cranial nerve is the 6th pharyngeal arch associated with?
Recurrent laryngeal branch of Vagus nerve (X)
What does the artery of the 6th arch become?
Right- pulmonary arteries
Left- ductus arteriosus
What muscles does the 6th pharyngeal arch give rise to?
Muscles of larynx
What is the fate of the 6th pharyngeal cartilage?
Lower thyroid cartilage
Cricoid cartilage
What other structures develop from the pharyngeal arches?
Tongue
Thyroid gland
Parathyroid glands
Part of pituitary gland
What is the oropharyngeal membrane comprised of?
Ectoderm externally
Endoderm internally
What prominences do the face develop from?
Fronto nasal
Mandibular
Maxillary
What is the stomatodeum?
A space between the maxillary prominences, covered by the oropharyngeal membrane
It is the precursor to the mouth and pituitary gland
What are the derivatives of the frontonasal prominence?
Forehead
Bridge of nose
Medial nasal prominence
Lateral nasal prominence
What are the derivatives of the medial nasal prominence?
Philtrum
Primary palate
Upper 4 incisors and associated jaw
What are the derivatives of the lateral nasal prominence?
Sides of nose
What are the derivatives of the maxillary prominence?
Cheeks
Lateral upper lip
Secondary palate
Lateral upper jaw
What are the derivatives of the mandibular prominence?
Lower lip
Lower jaw
What forms the primary palate?
Fusion of the medial nasal prominences
What forms the secondary palate?
Palatine shelves from the maxillary processes
How do the flat bones of the cranial vault form?
Membranous ossification
How to the irregular bones of the base of the skull form?
Endochondral ossification
