Editing Aponeurosis

{{Short description|Tissue which connects muscles to other organs}}
{{Infobox anatomy
| Name        = Aponeurosis
| Latin       = aponeurosis ([[plural]]: aponeuroses)
| Image       = Lumbar aponeurosis.jpg
| Caption     = Lumbar aponeurosis of the [[Visible Human Project|Visible Human Male]]
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An '''aponeurosis''' ({{IPAc-en|ˌ|æ|p|ə|nj|ʊəˈr|oʊ|s|ɪ|s}}; {{plural form}}: '''aponeuroses''') is a flattened [[tendon]]<ref name = "Willard_2012">{{cite journal | vauthors = Willard FH, Vleeming A, Schuenke MD, Danneels L, Schleip R | title = The thoracolumbar fascia: anatomy, function and clinical considerations | journal = Journal of Anatomy | volume = 221 | issue = 6 | pages = 507–536 | date = December 2012 | pmid = 22630613 | pmc = 3512278 | doi = 10.1111/j.1469-7580.2012.01511.x }}</ref> by which muscle attaches to bone or [[fascia]].<ref>{{Cite web |title=Definition of aponeurosis | work = Dictionary.com |url=https://www.dictionary.com/browse/aponeurosis |access-date=2023-05-16 |language=en}}</ref> Aponeuroses exhibit an ordered arrangement of collagen fibres, thus attaining high tensile strength in a particular direction while being vulnerable to tensional or shear forces in other directions.<ref name = "Willard_2012" /> They have a shiny, whitish-silvery color, are [[histologically]] similar to [[tendon]]s, and are very sparingly supplied with [[blood vessels]] and [[nerves]]. When dissected, aponeuroses are papery and peel off by sections. The primary regions with thick aponeuroses are in the [[Anatomical terms of location#Dorsal and ventral|ventral]] [[abdominal]] region, the dorsal [[lumbar]] region, the [[gizzard|ventriculus]] in birds, and the [[Anatomical terms of location#Hands and feet|palmar]] (palms) and [[Anatomical terms of location#Hands and feet|plantar]] (soles) regions.

==Anatomy==
===Anterior abdominal aponeuroses===
The anterior abdominal aponeuroses are located just superficial to the [[rectus abdominis muscle]]. It has for its borders the [[external oblique]], [[pectoralis muscle]]s, and the [[latissimus dorsi]].

===Posterior lumbar aponeuroses===
The posterior lumbar aponeuroses are situated just on top of the epaxial muscles of the thorax, which are [[multifidus spinae]] and [[sacrospinalis]].

===Palmar and plantar aponeuroses and extensor hood===
The [[Palmar aponeurosis|palmar aponeuroses]] occur on the palms of the hands. The [[extensor hood]]s are aponeuroses at the back of the fingers.
<br />The [[Plantar fascia|plantar aponeuroses]] occur on the plantar aspect of the foot. They extend from the [[calcaneus|calcaneal tuberosity]] then diverge to connect to the bones, ligaments and the dermis of the skin around the distal part of the metatarsal bones.

===Anterior and posterior intercostal membranes===
The anterior and posterior intercostal membranes are aponeuroses located between the ribs and are continuations of the external and internal [[intercostal muscles]], respectively.

===Scalp aponeuroses===
The [[epicranial aponeurosis]], or galea aponeurotica, is a tough layer of [[dense fibrous tissue]] which runs from the [[frontalis muscle]] anteriorly to the [[occipitalis]] posteriorly.

===Pennate muscles and aponeuroses===
[[Pennate muscle]]s, in which the muscle fibers are oriented at an angle to the line of action, typically have two aponeuroses.  Muscle fibers connect one to the other, and each aponeurosis thins into a [[tendon]] which attaches to bone at the origin or insertion site.

== Function ==
Like [[tendon]]s, aponeuroses attached to pennate muscles can be stretched by the forces of muscular contraction, absorbing energy like a spring and returning it when they recoil to unloaded conditions.<ref>{{cite journal | vauthors = Azizi E, Roberts TJ | title = Biaxial strain and variable stiffness in aponeuroses | journal = The Journal of Physiology | volume = 587 | issue = Pt 17 | pages = 4309–4318 | date = September 2009 | pmid = 19596897 | pmc = 2754367 | doi = 10.1113/jphysiol.2009.173690 }}</ref> Also serving as an origin or insertion site for certain muscles e.g latissimus dorsi.

== See also ==
* [[Aponeurosis of the obliquus externus abdominis]]
* Aponeurosis of the [[serratus posterior superior muscle]]
* [[Plantar aponeurosis]]
* [[Inguinal aponeurotic falx]]
* [[Bicipital aponeurosis]]
* [[Palatine aponeurosis]]
* [[Fascia]]

== References ==
{{Reflist}}

{{Connective tissue}}
{{Muscular system}}
{{Authority control}}

[[Category:Tissues (biology)]]