2nd semester: Embryology of EAR, NOSE, TONGUE Flashcards
Internal arises from thickening of surface ______ at level of developing brainstem in myencephalon
Ectoderm
Thickening of ectodermal surface -> ______ -> Otic pit
Otic placade
What portion will become the membranous labyrinth?
Otic vesicle
The Otic Vesicle will have 2 compartments. The VENTRAL component will become the _______
A. Saccule [Receptor for STATIC EQUILIBRIUM -> linear motion -> MACULA]
B. Cochlear duct [Receptor for HEARING -> ORGAN OF CORTI]
The Otic Vesicle will have 2 compartments. The DORSAL component will become the _______
A. Utricle [saccule w/ macula -> linear motion]
B. Semicircular ducts [receptor for CIRCULAR MOTION -> crista ampullaris]
C. Endolymphatic duct [diverticulum as otic vesicle DISENGAGE from ectoderm]
Middle arises from _____
Endoderm [1st pharyngeal pouch]
The 1st phrayngeal pouch is divided into 2. The DISTAL part forms the ______
tympanic cavity
The formation of the ossicles and muscles are derived from _____
mesoderm
The 1st phrayngeal pouch is divided into 2. The PROXIMAL part forms the ______
auditory tube/eustachian tube [connects to the nasopharyngeal part]
The ____ is directly connected to the tympanic membrane while ____ is to the oval window of entry to inner ear
Malleus
Stapes
Stapes arises from the cartilage of ______
2nd pharyngeal arch
Skeletal muscles and their attachment:
Tensory tympani: ________
________: attached to stapes
attached to malleus
stapedius muscle
The eardrum/tympanic membrane is the boundary between ______
OUTER and INNER ear
The pinna/auricle is the external portion of the ear.
The pharyngeal cleft -> gives rise to the ____
The pharyngeal arch -> gives rise to ____
skin [ectoderm]
elastic cartilage [mesoderm]
The ____ solid component of pharyngeal cleft and will disintegrate. IF NOT, will form congenital conductive deafness.
Meatal plug
The ____ will communicate with middle ear through tympanic membrane
Meatal plug
The eardrum is made of
epithelial lining from -> 1st pharyngeal cleft
endothelial lining from -> 1st pharyngeal pouch
Layer of CT -> ___ and ___ pharyngeal arches
1st
2nd
The nose arises from ___
surface ectoderm
When will the nose start to develop?
5th week of gestation
The developing ____ will eventually become the oral cavity
stomodeum
The developing telencephalon will become the ______
cerebrum
nasal placode -> depression -> ___ -> nasal sac -> ______
nasal pit
nasal cavity
nose: The MEDIAL nasal swelling will become the _____
nasal septum
The nasal septum will be continuous with ____
columella
nose: The LATERAL nasal swelling will become ______
ALA OF NOSE [nostrils]
What is the special type of lining that covers the nasal cavity?
Ectodermal epithelium [arises from nasal placode and becomes the olfactory epithelium; olfactory placode]
The tongue arises from what germ layer?
ENDOdermal layer [1st pharyngeal arch]
When does the tongue start to develop?
4th week of gestation
Tongue: The medial swelling from the 1st phrayngeal arch will become the _______
Tuberculum impar
Tongue: swellings on the lateral side of tuberculum impar will merge and form the _____ of the tongue
Anterior 2/3
The point of fusion of the 2 lateral lingual swelling is ______
median sulcus of the tongue
what are the 5 pharyngeal arches?
1,2,3,4,6
no 5 kasi mag disintegrate lang siya or hindi mag develop
The posterior 1/3 of the tongue will arise from
hypobonchial eminence
What is the fate of the 2nd pharyngeal arch associated with the tongue?
Capula
Majority of the 3rd and 4th pharyngeal arch develops into the
hypobranchial eminence [overshadows the capula]
Tongue: point of fusion between the anterior 2/3 & posterior 1/3 is a V-SHAPED structure known as
Terminal Sulcus
What important parts are found in the lingual papillae?
Taste buds
When does the lingual papillae develop?
around 11th to 13th week
