Development Of Pharyngeal Arches Flashcards
What does the pharyngeal apparatus consist of?
J
J
J
J
J
____ cells migrate from the forebrain, midbrain, and hindbrain.
Hindbrain populates the _____ and is divided into segments called _____.
Pharyngeal arch 1 streams from ____.
PA 2 streams from _____.
PA 3/4 streams from ____.
Pa 3 and 5 produce few ____.
NCC
Pharyngeal arches
Rhombomeres
R1-2
R4
R6-6
NCC
Each arch consists of a core of ____ covered externally by ____ and internally by ______.
Mesenchyme
Ectoderm
Endoderm
Mesenchyme is derived from ____ that migrate into arches during the _____ week.
Arches support the lateral walls of the ____.
NCC migration into the arches and differentiation into mesenchyme becomes the ______ and ______.
NCC; 4th
Primordial pharynx
Maxillary and mandibular prominences
____ arch separates into the maxillary and mandibular prominences.
During ____ week the PA2 overgrown PA3/4 to form the ____.
By end of 7th week the ____ disappears.
1st
Cervical sinus (ectodermal depression)
Cervical sinus
N
N
J
J
J
J
Meckel’s cartilage is the cartilage of _____.
PA 1
Riechert’s cartilage is the cartilage of ____.
Riechert’s plus the dorsal anlage form the ____ and ____.
Cartilage between the styloid and hyoid regress and the ____ forms the styloidhyoid L.
Ventral end of Riechert’s ossifies and forms the _____.
PA 2
Stapes and styloid process of temporal bone
Perichondrium
Lesser cornu/horn of hyoid bone
Third arch
J
4th and 6th arch cartilages
J
Muscular components of the PA are derived from ____ and _____.
What muscles do PA1- PA6 form? (Not PA5)
What CN go with each arch?
Paraxial mesoderm and prechordal plate
PA1: muscles of mastication (CN V)
PA2: stapedius and muscles of facial expression (CN VII)
PA3: stylopharyngeus m (CN IX)
PA4: cricothryroid, levator veli palatini, and constrictors of pharynx (CN X)
PA6: intrinsic muscles of the larynx (CN X)
Special visceral efferent supply ____ derived from the arches.
Special visceral afferent supply the ____ and ____ of the head and neck.
Muscles
Dermis and mucous membranes
Trigeminal N
J
Facial N
CN IX
J
Vagus
J
Primordial pharynx is derived form the ____. It widens cranially and joins the ____ but narrows as it joints the esophagus.
____ of the pharynx lines the internal aspects of the arches and the pharyngeal pouches.
Foregut; stomodeum
Endoderm
J
J
The ____ appear in the floors of the pharyngeal grooves. They form where epithelial of the grooves and pouches meet. They quickly are infiltrated and separated by ____.
The 1st pharyngeal membrane plus the intervening mesenchyme forms the _____.
Pharyngeal membranes
Mesenchyme
Tympanic membrane
The _____ of the pouches forms organs in head/neck.
The 1st pharyngeal pouch expands into the ____.
Endoderm
Tubotympanic recess
Y
Y
The 2nd pharyngeal pouch is obliterated as the ____ develops; but part of cavity remains as the ___, a depression between the palatoglossal and palatopharyngeal arches.
Palatine tonsil
Tonsillar sinus
J
J
The 3rd pharyngeal pouch separates into two regions?
By ____ week, the dorsal bulbar part differentiates into the _____.
Epithelium of elongated ventral parts proliferate and obliterate the cavities. The two parts come together forming the ____.
Solid, dorsal, bulbar part
Hollow, elongated, ventral part
Inferior parathyroid gland
Thymus
The 4th pharyngeal pouch expands into two parts?
By 6th week, the epithelium of the dorsal bulbar parts differentiate into the _____ and lies on the dorsal surface of the thyroid gland.
Dorsal, bulbar part
Elongated, ventral part
Superior parathyroid gland
____ separates the pharyngeal arches and are separated externally.
They arise during the ____ weeks.
The first pair become the ____.
Grooves 2-4 lie in the ____; all are obliterated by ____ week as the neck develops. Birth defects of ____ groove are common.
Pharyngeal grooves
4-5th
External acoustic meatus
Cervical sinus; 7th week; 2nd groove
Cervical (brachial) cysts are remnants of the ____ or ____.
Cysts lie free in neck, inferior to the angle of the mandible.
Cervical sinus; 2nd groove
The thyroid gland is the first endocrine gland to develop from ____.
It forms a median endothermal thickening in the floor of the ____.
It descends in the neck with tongue growth and passes ventral to developing hyoid bone and laryngeal cartilages. It connects to the tongue by a narrow tube called the ____.
Thyroid primordium
Primordial pharynx
Thyroglossal duct
During the ____ week, a solid mass of endodermal cells is broken up into epithelial cords by vascular ____.
____ has degenerated and disappeared.
Proximal opening of the duct persists as ____ on the dorsal tongue.
____ extends superiorly from the isthmus.
7th
Mesenchyme
Thyroglossal duct
Foramen cecum
Pyramidal lobe
During the ____ week, the cords have divided into cellular groups and a lumen.
The cells are arranged in a single layer around the ____.
10th
Thyroid follicles
During the ____ week, the colloid appears and synthesis of TH occurs.
During ____ week the levels of TSH and thyroxine increase.
During _____ fetal TSH and thyroxine reach adult levels.
11th
20th
35th
Elongated ventral part of each 4th pouch develops into an _____ and fuses with the thyroid gland.
Cells disseminate within the thyroid and form _____ that will produce calcitonin. These cells form from ____.
Ultimopharyngeal body
Parafollicular cells
NCC
____ is abnormal development of the components of the 1st arch.
Causes malformation of eyes, ear, mandible, and palate.
This results from insufficient migration of ____ into first arch during ____.
First pharyngeal arch syndrome
NCC; 4th week
Treacher-Collins syndrome
J
____ is associated with hypoplasia of the mandible, cleft palate, and defects of eyes and ears.
Initiating defect is a small mandible called ____; results in posterior displacement of the tongue
Pierre robin sequence
Micrognathia
