Wikia

Psychology Wiki

Ligament

Talk0
34,142pages on
this wiki

Assessment | Biopsychology | Comparative | Cognitive | Developmental | Language | Individual differences | Personality | Philosophy | Social |
Methods | Statistics | Clinical | Educational | Industrial | Professional items | World psychology |

Biological: Behavioural genetics · Evolutionary psychology · Neuroanatomy · Neurochemistry · Neuroendocrinology · Neuroscience · Psychoneuroimmunology · Physiological Psychology · Psychopharmacology (Index, Outline)


In anatomy, the term ligament is used to denote three different types of structures:[1]

  1. Fibrous tissue that connects bones (or two different parts of a single bone). They are sometimes called "articular ligaments"[2], "fibrous ligaments", or "true ligaments".
  2. A fold of peritoneum or other membrane
  3. The remnants of a tubular structure from the fetal period of life

The first meaning is most commonly what is meant by the term "ligament". After briefly discussing the other two types of ligaments, the remainder of this article will focus upon the first type.

Peritoneal ligamentsEdit

Certain folds of peritoneum are referred to as ligaments.

Examples include:

Fetal remnant ligamentsEdit

Certain tubular structures from the fetal period are referred to as ligaments after they close up and turn into cord-like structures:

Fetal Adult
ductus arteriosus ligamentum arteriosum
extra-hepatic portion of the fetal left umbilical vein ligamentum teres hepatis (the "round ligament of the liver").
intra-hepatic portion of the fetal left umbilical vein (the ductus venosus) ligamentum venosum
distal portions of the fetal left and right umbilical arteries medial umbilical ligaments

Articular ligamentsEdit

Gray298

Diagrammatic section of a symphysis.

In its most common use, a ligament is a short band of tough fibrous connective tissue composed mainly of long, stringy collagen fibres. Ligaments connect bones to other bones to form a joint. (They do not connect muscles to bones; that is the function of tendons.) Some ligaments limit the mobility of articulations, or prevent certain movements altogether.

Capsular ligaments are part of the articular capsule that surrounds synovial joints. They act as mechanical reinforcements. Extra-capsular ligaments join bones together and provide joint stability.

Ligaments are slightly elastic; when under tension, they gradually lengthen. This is one reason why dislocated joints must be set as quickly as possible: if the ligaments lengthen too much, then the joint will be weakened, becoming prone to future dislocations. Athletes, gymnasts, dancers, and martial artists perform stretching exercises to lengthen their ligaments, making their joints more supple. The term double-jointed refers to people who have more elastic ligaments, allowing their joints to stretch and contort further. The medical term for describing such double-jointed persons is hyperlaxity and double-jointed is a synonym of hyperlax.

The study of ligaments is known as desmology.

The consequence of a broken ligament can be instability of the joint. Not all broken ligaments need surgery, but if surgery is needed to stabilise the joint, the broken ligament can be joined. Scar tissue may prevent this. If it is not possible to fix the broken ligament, other procedures such as the Brunelli Procedure can correct the instability. Instability of a joint can over time lead to wear of the cartilage and eventually to osteoarthritis.

ExamplesEdit

KneeEdit

Head and neckEdit

PelvisEdit

ThoraxEdit

WristEdit

OtherEdit

ReferencesEdit

  1. Dictionary at eMedicine ligament
  2. Dorlands/Elsevier l_09/12488504

External linksEdit

Wiktionary-logo-en
Look up ligament in Wiktionary, the free dictionary.






Around Wikia's network

Random Wiki