Difference between revisions of "Sensory - Balance Development"

From Embryology
Line 1: Line 1:
 
[[File:Gray0924.jpg|300px|right]]
 
[[File:Gray0924.jpg|300px|right]]
 
==Introduction==
 
==Introduction==
 +
The sensory system for balance arises as part of the inner ear development from the otic placode then otic vesicle. Three flattened pouch of epithelium extend from the otic vesicle from which the final semicircular canals will be fashioned. During early development the epithelia of two apposing wall of the pouch approach each other and form a fusion plate, that clears to form a hole generating the loop of the remaining tissue as semicircular canals. Fusion plate clearing has been suggested to occur due to both apoptosis and epithelial-mesenchymal transition.<ref><pubmed>18648181</pubmed></ref>
 +
 +
The adult semicircular canals are fluid-filled tubules that are arranged perpendicularly to each other in inner ear and remain connected to the cochlea. This tubular arrangement allows detection of movement in all 3 planes.
  
 
[[File:Vestibular labyrinth cartoon.jpg|thumb|Vestibular labyrinth cartoon<ref><pubmed>19723316</pubmed></ref>]]
 
[[File:Vestibular labyrinth cartoon.jpg|thumb|Vestibular labyrinth cartoon<ref><pubmed>19723316</pubmed></ref>]]

Revision as of 01:34, 11 June 2010

Gray0924.jpg

Introduction

The sensory system for balance arises as part of the inner ear development from the otic placode then otic vesicle. Three flattened pouch of epithelium extend from the otic vesicle from which the final semicircular canals will be fashioned. During early development the epithelia of two apposing wall of the pouch approach each other and form a fusion plate, that clears to form a hole generating the loop of the remaining tissue as semicircular canals. Fusion plate clearing has been suggested to occur due to both apoptosis and epithelial-mesenchymal transition.[1]

The adult semicircular canals are fluid-filled tubules that are arranged perpendicularly to each other in inner ear and remain connected to the cochlea. This tubular arrangement allows detection of movement in all 3 planes.

Vestibular labyrinth cartoon[2]
Hearing Links: Introduction | inner ear | middle ear | outer ear | balance | placode | hearing neural | Science Lecture | Lecture Movie | Medicine Lecture | Stage 22 | hearing abnormalities | hearing test | sensory | Student project

  Categories: Hearing | Outer Ear | Middle Ear | Inner Ear | Balance

Historic Embryology - Hearing 
Historic Embryology: 1880 Platypus cochlea | 1892 Vertebrate Ear | 1902 Development of Hearing | 1906 Membranous Labyrinth | 1910 Auditory Nerve | 1913 Tectorial Membrane | 1918 Human Embryo Otic Capsule | 1918 Cochlea | 1918 Grays Anatomy | 1922 Human Auricle | 1922 Otic Primordia | 1931 Internal Ear Scalae | 1932 Otic Capsule 1 | 1933 Otic Capsule 2 | 1936 Otic Capsule 3 | 1933 Endolymphatic Sac | 1934 Otic Vesicle | 1934 Membranous Labyrinth | 1934 External Ear | 1938 Stapes - 7 to 21 weeks | 1938 Stapes - Term to Adult | 1940 Stapes | 1942 Stapes - Embryo 6.7 to 50 mm | 1943 Stapes - Fetus 75 to 150 mm | 1946 Aquaductus cochleae and periotic (perilymphatic) duct | 1946 aquaeductus cochleae | 1948 Fissula ante fenestram | 1948 Stapes - Fetus 160 mm to term | 1959 Auditory Ossicles | 1963 Human Otocyst | Historic Disclaimer

Some Recent Findings

  • Lmo4 in the vestibular morphogenesis of mouse inner ear[3] "Our results demonstrate that Lmo4 controls the development of the dorsolateral otocyst into semicircular canals and cristae through two distinct mechanisms: regulating the expression of otic specific genes and stimulating the proliferation of the dorsolateral part of the otocyst."
  • Saccular function and motor development in children with hearing impairments[4] "The purpose of this study was to evaluate saccular function in children with hearing impairments using the Vestibular Evoked Myogenic Potential (VEMP). The impact of the saccular hypofunction on the timely maturation of normal balance strategies was examined using the Movement Assessment Battery for Children (Movement ABC). ...No VEMP was evoked in two thirds of the hearing impaired (HI) children in response to the bone-conducted stimulus. Children who were reportedly hearing impaired since birth had significantly poorer scores when tested with the Movement ABC."

Inner Ear Labyrinth

Stage 13 otocyst
Stage 22 ear
  • Cochlea - Otic vesicle - Otic placode (ectoderm)
  • Semicircular canals - Otic vesicle - Otic placode (ectoderm)
  • Saccule and utricle - Otic vesicle - Otic placode (ectoderm)

Cranial Nerve VIII

  • Auditory component - Otic vesicle and neural crest (ectoderm)
  • Vestibular component - Otic vesicle and neural crest (ectoderm)
  • The inner ear is derived from a pair of surface sensory placodes (otic placodes) in the head region.
  • These placodes fold inwards forming a depression, then pinch off entirely from the surface forming a fluid-filled sac or vesicle (otic vesicle, otocyst).
  • The vesicle sinks into the head mesenchyme some of which closely surrounds the otocyst forming the otic capsule.
  • The otocyst finally lies close to the early developing hindbrain (rhombencephalon) and the developing vestibulo-cochlear-facial ganglion complex.

Links: Inner Ear

References

  1. <pubmed>18648181</pubmed>
  2. <pubmed>19723316</pubmed>
  3. <pubmed>19913004</pubmed>
  4. <pubmed>20148080</pubmed>


Reviews

Articles

  • Development of the mouse cochlea database (MCD). Santi PA, Rapson I, Voie A. Hear Res. 2008 Sep;243(1-2):11-7. Epub 2008 May 25. PMID:18603386 | PMC2628570
  • A mathematical model of human semicircular canal geometry: a new basis for interpreting vestibular physiology. Bradshaw AP, Curthoys IS, Todd MJ, Magnussen JS, Taubman DS, Aw ST, Halmagyi GM. J Assoc Res Otolaryngol. 2010 Jun;11(2):145-59. Epub 2009 Dec 1. PMID: 19949828

Search PubMed

May 2010 "Inner Ear Development" All (4027) Review (452) Free Full Text (750)

Search Pubmed: Balance Development | Vestibular Development |Semicircular Canal Development

External Links

Glossary Links

Glossary: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers | Symbols | Term Link

Cite this page: Hill, M.A. (2021, May 18) Embryology Sensory - Balance Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Sensory_-_Balance_Development

What Links Here?
© Dr Mark Hill 2021, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G