FACTOID # 13: New York has America's lowest percentage of residents who are veterans.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
   
 
WHAT'S NEW
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Pharyngeal arch
Enlarge
Schematic of developing fetus with first, second and third arches labeled.

The branchial arches, also known as pharyngeal arches, develop during the fourth and fifth week in utero as a series of mesodermal outpouchings on the left and right sides of the developing pharynx. These grow and join in the ventral midline. The first or mandibular arch, as the first to form, seperates the mouth pit or stomodeum from the pericardium. By differential growth the neck elongates and new arches form, so the pharynx has six arches ultimately. Pharyngeal or branchial pouches form on the endodermal side between the arches, and pharyngeal grooves (or clefts) form from the lateral ectodermal surface of the neck region to seperate the arches. The pouches line up with the clefts, and these thin segments become gills in fish. In mammals the endoderm and ectoderm not only remain intact, but continue to be seperated by a mesoderm layer. ‹ The template below has been proposed for deletion. ... It has been suggested that endoderm be merged into this article or section. ... A right-handed Cartesian coordinate system, presenting the z (up) vector and y (forward) vector, the right is defined to be the positive x vector. ... The pharynx is the part of the digestive system and respiratory system of many animals immediately behind the mouth and in front of the esophagus. ... The pericardium is a double-walled sac that contains the heart and the roots of the great vessels. ... It has been suggested that endoderm be merged into this article or section. ... It has been suggested that endoderm be merged into this article or section. ... The neck is the part of the body on many limbed vertebrates that distinguishes the head from the torso or trunk. ... gills of a Smooth Newt In aquatic organisms, gills are a respiratory organ for the extraction of oxygen from water and for the excretion of carbon dioxide. ...


Each pharyngeal arch has a cartilaginous bar, a muscle component which differentiates from the cartilagenous tissue, an artery, and a cranial nerve. Cartilage is a type of dense connective tissue. ... A top-down view of skeletal muscle Muscle is a contractile form of tissue. ... Cranial nerves are nerves which start directly from the brainstem instead of the spinal cord. ...


There are 6 pharyngeal arches. More is known about the fate of the first arch than the remaining 5. The first three contribute to structures above the larynx, while the last three contribute to the larynx and trachea. The larynx (plural larynges), or voicebox, is an organ in the neck of mammals involved in protection of the trachea and sound production. ... The trachea (IPA /treikiÉ™/), or windpipe, is a tube extending from the larynx to the bronchi in mammals, and from the pharynx to the syrinx in birds, carrying air to the lungs. ...

Contents


First pharyngeal arch

It has been suggested that first pharyngeal arch be merged into this article or section. (Discuss)
  • Also called the "mandibular arch". Follow the link (above) for more information.

Image File history File links Please see the file description page for further information. ...

Second pharyngeal arch

stapes The stapes or stirrup is the stirrup-shaped small bone or ossicle in the middle ear which attaches the incus to the fenestra ovalis, the oval window which is adjacent to the vestibule of the inner ear. ... In anatomy, the styloid process is any sharp protrusion of a bone. ... The hyoid bone (Os Hyoideum; Lingual Bone) is a bone in the human neck, not articulated to any other bone; it is supported by the muscles of the neck and in turn supports the root of the tongue. ... Photographs from the 1862 book Mécanisme de la Physionomie Humaine by Guillaume Duchenne. ... Buccinator The buccinator is a muscle of which the bulk of is located in the cheeks. ... The platysma is a superficial muscle that stretches from the clavicle to the mandible overlapping the sternocleidomastoid. ... The stapedius is the smallest striated muscle in the human body. ... The Digastric is a muscle of the human body. ... The facial nerve is seventh of twelve paired cranial nerves. ...

Third pharyngeal arch

The Stylopharyngeus muscle is a muscle of the human body. ... The glossopharyngeal nerve is the ninth of twelve cranial nerves. ...

Fourth to sixth pharyngeal arches

The cartilages of the larynx. ... The cricoid cartilage, or simply cricoid, is the only complete ring of cartilage around the trachea. ... The arytenoid cartilages are a pair of small pyramid-shaped cartilages, at the upper rear of the larynx, to which the vocal cords are attached. ... The larynx (plural larynges), or voicebox, is an organ in the neck of mammals involved in protection of the trachea and sound production. ... The pharynx is the part of the digestive system and respiratory system of many animals immediately behind the mouth and in front of the esophagus. ... The vagus nerve is tenth of twelve paired cranial nerves and is the only nerve that starts in the brainstem (somewhere in the medulla oblongata) and extends all the way down past the head, right down to the abdomen. ...

Branchial pouches

First pouch

  • This is the only pouch in which the endoderm and ectoderm remain close together, as the tympanic membrane. There is minimal mesoderm in the tympanic membrane.
  • The endoderm becomes the auditory tube, middle ear and mastoid antrum.
  • The ectoderm becomes the external acoustic meatus

The tympanum or tympanic membrane, colloquially known as eardrum, is a thin membrane that separates the outer ear from the middle ear. ... For an alternative meaning, see ear (botany). ...

Second pouch

  • Contributes to the middle ear, tonsils, supplied by the glossopharyngeal nerve.

The Palatine tonsils. ...

Third pouch

Human parathyroid glands The parathyroid glands are endocrine glands in the neck, usually located within the thyroid gland, which produce parathyroid hormone. ... In human anatomy, the thymus is a ductless gland located in the upper anterior portion of the chest cavity. ...

Fourth pouch

  • Derivatives include the superior parathyroid glands

Fifth pouch

The ultimobranchial body or gland is a small organ found in the neck region of many animals. ... Calcitonin is a a 32 amino acid polypeptide hormone that is produced in humans primarily by the C cells of the thyroid, and in many other animals in the ultimobranchial body. ... The thyroid gland and its relations In anatomy, the thyroid (IPA θaɪɹoɪd) is an endocrine gland. ...

References

  • [[|Harris, Edward F.]] () ( 2002). ""  [ Craniofacial Growth and Development]. ..
  • McMinn, R., 1994. Last's anatomy: Regional and applied (9th ed).

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m