H&N 2.2 branchial arches Flashcards
(39 cards)
When does the neural tube form?
Week 3
How does the neural tube form?
notochord signals for overlying ectoderm to thicken, causing a slipper shaped elevation of neurectoderm. This rolls up to from the neural tube
What does the anterior neural tube become?
The future brain, therefore it rapidly proliferates
What are the 3 vesicle stages of the brain development?
prosencephalnon- forebrain
mesencephalon- midbrain
rhombencephalon- hindbrain
Where does the pharynx extend from and to?
What are it’s divisions?
From the base of the skull to the inferior border of the cricoid cartilage.
Nasopharynx
Oropharynx
Laryngopharynx
What are the pharyngeal arches?
Mesenchymal proliferations in the neck region of the embryo
how many pharyngeal arches are there?
5 in total,
1,2,3,4, and 6
What 2 distinct portions does the first pharyngeal arch split into?
Maxillary prominence and the mandibular prominence
What cells are crucial for the development of the head and neck?
Neural crest cells, which migrate from elsewhere.
Which nerves are derived from the pharyngeal arches?
Ph arch 1- trigeminal nerve
Ph arch 2- facial nerve
Ph arch 3- glossopharyngeal nerve
Ph arch 4 and 6- vagus nerve
What muscles are derived from Ph arch 1?
Muscles of mastication
What muscles are derives from Ph arch 2?
Muscles of facial expression
What muscles are derived from Ph arch 3?
What’s its function?
The stylopharyngeus only- aids in elevating pharynx and larynx during swallowing.
What muscles are derived from Ph arch 4?
Cosntrictors of the pharynx,
What muscles are derived from Ph arch 6?
Intrinsic muscles of the larynx.
What nerve gives special sensation to the anterior 2/3 of the tongue?
Chorda tympani, a branch of the facial nerve
What nerve gives special sensation to the posterior 1/3 of the tongue?
The glossopharyngeal nerve.
What are the 2 divisions of the vagus nerve, and from which Ph arches are they derived?
Ph arch 4- superior laryngeal nerve
Ph arch 6- recurrent laryngeal nerve.
What’s the function of the superior laryngeal nerve?
innervates constrictors of the phayrnx
What’s the function of hte recurrent laryngeal nerve?
Innervates the intrinsic muscles of the larynx
What cartilage is derived from Ph arch 1?
Meckel’s cartilage, derived from the mandibular prominence.
What are the derivatives fo the cartilage bar fromed from Ph arch 1?
Template for the mandible (membranous ossification)
malleus, incus.
What cartilage is derived from Ph arch 2?
Reichert’s cartilage.
What are the derivatives of the cartilage bar formed from Ph arch 2?
The superior hyoid bone,
The styloid process
The stapedius.
