PA Development And Adult PA Derivatives Flashcards
What are the embryonic/developmental origin for the head and neck structures
Pharyngeal arches and frontonasal region
What PA and embryonic origin form the face adn pharynx
PA 1 and FN form the face.
PA 2,3,4,6 form pharynx
What germ layer covers the external surfaces and lines oral cavity proper
Ectoderm
What germ layers form the central core mesoderm
PA head mesoderm and ectomesenchyme
What germ layer internal line the lumen of pharynx
Endoderm
What germ layer differentiates into motor and sensory neutrons to innervate each arch
Neuroectoderm/ neural crest
What does each arch contain
Epithelium, CT, muscle, nervous component
What do the germ layers of each specific pharyngeal arch give rise to
Pharyngeal arch derivatives
________ provide motor and sensory innervation to the pharyngeal arch derivatives
Cranial nerves
T/F—each arch is associated with a specific cranial nerve but all the structures arising from that arch do not receive innervation from that CN
FALSE! All structures DO receive innervation from that CN
What CN innervate what arches
PA 1- trigeminal (CN V)
PA 2- facial (CN VII)
PA 3- glossopharyngeal (CN IX)
PA 4/6- vagus (CN X)
What fibers are carried to skeletal muscle by CNs in each arch
motor (SVE)
What fibers are carried to regions of mucosa from the CNs associated with each arch
General sensory (GSA)—pain, temp, touch
What fibers do CN VII, IX, and X carry
Parasympathetic fibers of ANS (GVE). Autonomic neurons control glandular secretion
What CNs carry fibers for taste (SVA)
CN VII, IX, X
SVE
Special visceral afferent. Motor nerves supplying skeletal muscle.
GSA
General somatic afferent and this refers to pain, temp, touch, proprioception
GVE
General visceral efferent refers to autonomic innervation
SVA
Special visceral afferent refers to special sense fibers that transmit taste
T/F—the location of the mucosa or skin in the adult corresponds to where the PA was located
True
The pattern of _______ __________ of the mucosa reflects which PA fave rise to the mucosa
Sensory innervation
Skin will always be ______ derived
Ectoderm
Skin covers what areas of the head and is derived from what arch
Face, ear, external auditory meatus, and is ectoderm from PA 1
What gives sensory innervation to teh skin of the face
Trigeminal (v2, v3) which is the CN of PA 1
What does the V1 division of hte trigeminal nerve innervate
Derivatives of the frontonasal region
What region of mucosa is derived from PA 1
Oral cavity proper—ectoderm
Nasopharynx-endoderm
What region of mucosa is derived from PA 2
Palatine tonsil which is the boundary b/w oral cavity and oropharynx
What region of mucosa is derived from PA 3
Region of the oropharynx and posterior 1/3 of the tongue
What region of mucosa is derived form PA 4
Region of the laryngopharynx/larynx which is the area from the epiglottis to the region above the vocal cords
What region of mucosa is derived from PA 6
Region of the larynx—vocal cords and below
What accessory structures are derived form PA
Tonsils (all 4), auditory tube, thymus, parathyroid, thyroid, external auditory meatus
What germ layer will all structures of the pharynx be from
Endoderm
Floor and roof derivatives __________________
Develop from endoderm in the midline of the tube. Adult structures may migrate to final position
Pouch derivatives develop from ______________________
Walls of tube—adult structures that develop may migrate to final position
What three things migrate to their final position
Thyroid epithelial cells, thymus epithelial reticular cells, parathyroid epithelial cells (chief/oxyphil)
What is the developmental precursor for the ant 2/3 of the tongue and PA
Lateral lingual swellings
Floor of PA 1
What is the developmental precursor and PA for tongue mucosa of post 1/3
Hypobranchial eminance
Floor of PA 3
What is the developmental precursor and PA for the lingual tonsil mucosa
Hypobranchial eminence and floor of PA 3
What is the developmental precursor and PA for the auditory tube
No precursor
PA 1 pouch
What is the developmental precursor and PA for the palatine tonsil mucosa
No precursor
PA 2 pouch
What is the developmental precursor and PA for pharyngeal tonsil mucosa
no precursor
PA 1 roof
What is the developmental precursor and PA for
What is the developmental precursor and PA for thyroid epithelial cells
Foramen cecum
Floor PA 2 btwn 1st and 3rd arch
What is the developmental precursor and PA for thymus epithelial reticular cells
No precursor
PA 3 pouch
What is the developmental precursor and PA for parathyroid epithelial cells
PA 3 and 4 pouch
What is the developmental precursor and PA for epiglottis laryngeal mucosa and cartilage
Epiglottic swelling, aryepiglottic swelling
Floor region of PA4
Floor region of PA 6
What are all floor/roof derivatives and pouch/ wall derivatives
Midline structures
Bilateral structures
What is a developmental precursor
An intermediate structure that transiently develop that may disappear of give rise to adult structures
Do all adult structures have developmental precursors
No
____________ is the germ layer in each PA that gives rise to a specific group of muscles (in head)
Head mesoderm
Does muscle migrate ?
Yes! So the final location of muscle may be diff than where its PA originated
Muscle of PA 1
Muscles of mastication. Ant digastric, mylohyoid, tensor tympani, tensor veli palatini
Muscles of PA 2
Muscles of facial expression, post digastric, stampedius, stylohyoid
Muscles of PA 3
Stylopharyngeus
Muscles of PA 4
Palatial, pharyngeal, or constrictors , adn cricothyroid m
Muscles of PA 6
Laryngeal muscles—-vocalis, or arytenoid is part of name
What muscles in the head do not come from head mesoderm and are not considered a muscle derivative of PA
Tongue muscles ! And they are innervated by CN XII which is not a PA nerve. They come from parasail mesoderm
T/F—if the CN innervation to a muscle is not provided by V, VII,IX, Or X it can still be considered a PA derivative
FALSE! It CANNOT be a PA derivative if not innervated by one of the PA CN’s
What germ layer gives rise to all CT, bone, and cartilage
Ectomesenchyme
How do bones ossify vs cartilage
Bones- intramembranous
Cartilage- endochondral or stays as cartilage
Cartilaginous precursors form what PA’s ossify to form bones
1,2,3
Bones originating form __________ contribute to membranous viscerocranium
Frontonasal region
Cartilaginous precursors of the PA which ossify contribut to waht
Facial skeleton. Many bones form PA 1,2,3 are also classified as [art of membranous viscerocranium
List the PA’s and their associated bones, cartilage, CT of face and neck
PA1–facial skeleton (14 bones0
PA2/3–hyoid bone, stapes, styloid
PA4–epiglottis/thyroid cartilage
PA6–cricoid and laryngeal cartilages
