Ligament
Diagram of the right knee.
Latin	ligamenta

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

1. Fibrous tissue that connects bones to other bones. 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.

The study of ligaments is known as desmology (from Greek δεσμός, desmos, "string"; and -λογία, -logia).

Contents 1 Peritoneal ligaments 2 Fetal remnant ligaments 3 Articular ligaments 3.1 Examples 3.1.1 Knee 3.1.2 Head and neck 3.1.3 Pelvis 3.1.4 Thorax 3.1.5 Wrist 4 See also 5 References 6 External links

[edit] Peritoneal ligaments

Certain folds of peritoneum are referred to as ligaments.

Examples include:

• The hepatoduodenal ligament, that surrounds the hepatic portal vein and other vessels as they travel from the duodenum to the liver.
• The broad ligament of the uterus, also a fold of peritoneum.
• The suspensory ligament of the ovary

[edit] Fetal remnant ligaments

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

[edit] Articular ligaments

In its most common use, a ligament is a band of tough, fibrous dense regular connective tissue comprising attenuated collagenous fibers. 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. Intra-capsular ligaments, which are much less common, also provide stability but permit a far larger range of motion. Cruciate ligaments occur in pairs.

Ligaments are elastic; when under tension, they gradually lengthen, unlike tendons which are inelastic. 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 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 repaired. 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.

[edit] Examples

[edit] Knee

• Anterior cruciate ligament (ACL)
• Lateral collateral ligament (LCL)
• Posterior cruciate ligament (PCL)
• Medial collateral ligament (MCL)
• Cranial cruciate ligament (CrCL) - quadruped equivalent of ACL
• Caudal cruciate ligament (CaCL) - quadruped equivalent of PCL

[edit] Head and neck

• Cricothyroid ligament
• Periodontal ligament
• Suspensory ligament of the lens

[edit] Pelvis

• Anterior sacroiliac ligament
• Posterior sacroiliac ligament
• Sacrotuberous ligament
• Sacrospinous ligament
• Inferior pubic ligament
• Superior pubic ligament
• Suspensory ligament of the penis

[edit] Thorax

• Suspensory ligament of the breast

[edit] Wrist

• Palmar radiocarpal ligament
• Dorsal radiocarpal ligament
• Ulnar collateral ligament
• Radial collateral ligament

[edit] See also

• Joint
• Brostrom procedure

[edit] References

1. ^ ligament at eMedicine Dictionary
2. ^ ligament at Dorland's Medical Dictionary

[edit] External links

Look up ligament in Wiktionary, the free dictionary.

• Exhaustive list of ligaments

v • d • e Joints (TA A03.0, GA 3.284) Types fibrous: Gomphosis · Suture · Syndesmosis · Interosseous membrane cartilaginous: Synchondrosis · Symphysis synovial: Plane joint · 1° (Hinge joint, Pivot joint) · 2° (Condyloid joint, Saddle joint) · 3° (Ball and socket joint) by range of motion: Synarthrosis · Amphiarthrosis · Diarthrosis Terminology Kinesiology · Anatomical terms of motion · Agonist/Antagonist Motions general: Flexion/Extension · Adduction/Abduction · Internal rotation/External rotation · Elevation/Depression specialized/upper limbs: Protraction/Retraction · Supination/Pronation specialized/lower limbs: Plantarflexion/Dorsiflexion · Eversion/Inversion Components capsular: Articular capsule (Synovial membrane, Fibrous membrane) · Synovial fluid · Synovial bursa · Articular disk/Meniscus extracapsular: Ligament · Enthesis joint navs: anat, non-congenital arthropathies/deformities/dorsopathies/soft tissue arthropathy/congenital, eponymous signs, proc

v • d • e Joints and ligaments of head and neck (TA A03.1.03-08, GA 3.287) Temporomandibular capsule · articular disk lateral (temporomandibular ligament) · medial (sphenomandibular ligament, stylomandibular ligament) Atlanto-occipital capsule · membranes (anterior atlantoöccipital membrane · posterior atlantoöccipital membrane)

v • d • e Joints and ligaments of upper limbs (TA A03.5, GA 3.313) Shoulder Sternoclavicular Anterior sternoclavicular · Posterior sternoclavicular · Interclavicular · Costoclavicular Acromioclavicular Syndesmoses: Coracoacromial · Superior transverse scapular · Inferior transverse of scapula Synovial: Acromioclavicular · Coracoclavicular (trapezoid, conoid) Glenohumeral Coracohumeral · Glenohumeral (superior, middle, and inferior) · Transverse humeral · Glenoid labrum Elbow Humeroradial Radial collateral Humeroulnar Ulnar collateral Proximal radioulnar Anular · Oblique cord Forearm Distal radioulnar Volar radioulnar · Dorsal radioulnar · Interosseous membrane of forearm Joints of hand Wrist/radiocarpal Palmar radiocarpal · Dorsal radiocarpal · Palmar ulnocarpal · Ulnar collateral · Radial collateral Intercarpal, midcarpal Pisohamate · Scapholunate Carpometacarpal Dorsal carpometacarpal · Palmar carpometacarpal (pisometacarpal) Intermetacarpal Deep transverse metacarpal · Superficial transverse metacarpal Metacarpophalangeal Palmar · Collateral Interphalangeal Palmar · Collateral Other Carpal tunnel · Ulnar canal

v • d • e Joints and ligaments of torso (TA A03.02-04, GA 3.299) Vertebral column Syndesmosis articulations of vertebral bodies: anterior longitudinal ligament · posterior longitudinal ligament articulations of vertebral arches: ligamenta flava · supraspinous ligament (nuchal ligament) · interspinal ligament · intertransverse ligament Synchondrosis intervertebral disc (annulus fibrosus, nucleus pulposus) Synovial joint Atlanto-axial (lat + med) capsule · atlantoaxial ligaments (anterior, posterior) · Cruciate ligament of atlas (Transverse ligament of atlas) Alar ligament · Apical ligament of dens · Tectorial membrane of atlanto-axial joint Zygapophysial no ligaments Lumbosacral iliolumbar ligament Sacrococcygeal anterior sacrococcygeal ligament · posterior sacrococcygeal ligament Thorax Costovertebral articulation of head of rib: radiate ligament · interarticular ligament costotransverse: Lumbocostal ligament Sternocostal interarticular sternocostal ligament · radiate sternocostal ligaments · costoxiphoid ligaments Interchondral no ligaments Costochondral no ligaments Pelvis Syndesmoses of pelvic girdle Obturator membrane · Obturator canal Pubic symphysis superior pubic ligament · inferior pubic ligament Sacroiliac anterior sacroiliac ligament · posterior sacroiliac ligament · interosseous sacroiliac ligament ligaments connecting the sacrum and ischium: sacrotuberous ligament · sacrospinous ligament Greater sciatic foramen · Lesser sciatic foramen

v • d • e Joints and ligaments of lower limbs (TA A03.6, GA 3.333) Coxal/hip femoral (iliofemoral, pubofemoral, ischiofemoral) · head of femur · transverse acetabular Knee-joint Anterior meniscofemoral ligament · Posterior meniscofemoral ligament extracapsular: patellar · popliteal (oblique, arcuate) · collateral (medial/tibial, fibular/lateral) intracapsular: cruciate (anterior, posterior) · menisci (medial, lateral) · transverse Infrapatellar fat pad Tibiofibular Superior tibiofibular anterior of the head of the fibula · posterior of the head of the fibula Inferior tibiofibular anterior of the lateral malleolus · posterior of the lateral malleolus other Interosseous membrane of leg Joints of foot Talocrural/ankle medial: medial of talocrural joint/deltoid (anterior tibiotalar, posterior tibiotalar, tibiocalcaneal, tibionavicular) lateral: lateral collateral of ankle joint (anterior talofibular, posterior talofibular, calcaneofibular) Subtalar/talocalcaneal anterior/posterior · lateral/medial · interosseous Transverse tarsal Talocalcaneonavicular dorsal talonavicular · plantar calcaneonavicular/spring · bifurcated (calcaneonavicular) Calcaneocuboid dorsal calcaneocuboid · long plantar · plantar calcaneocuboid · bifurcated (calcaneocuboid) Distal intertarsal Cuneonavicular plantar · dorsal Cuboideonavicular plantar · dorsal Intercuneiform plantar · dorsal · interosseous Other Tarsometatarsal/Lisfranc plantar · dorsal Intermetatarsal/metatarsal plantar · dorsal · interosseous · superficial transverse · deep transverse Metatarsophalangeal plantar · collateral Interphalangeal plantar · collateral Arches Longitudinal · Transverse

v • d • e Abdominopelvic cavity: Peritoneal ligaments, mesenteries, and folds (TA A10.1.02, GA 11.1147) Abdominal From ventral mesentery Lesser omentum: Hepatoduodenal ligament · Hepatogastric ligament Liver: Coronary ligament (Left triangular ligament, Right triangular ligament, Hepatorenal ligament) · Falciform ligament (Round ligament of liver and Ligamentum venosum in it, but not of it) From dorsal mesentery Greater omentum: Gastrophrenic ligament · Gastrocolic ligament · Gastrosplenic ligament Mesentery: Transverse mesocolon · Sigmoid mesocolon · Mesoappendix · Root of the mesentery Splenorenal ligament · Phrenicocolic ligament Folds: Umbilical folds (Supravesical fossa, Medial inguinal fossa, Lateral inguinal fossa) · Ileocecal fold Peritoneal cavity Greater sac · Lesser sac · Omental foramen Urogenital peritoneum Uterus/ovaries Broad ligament of the uterus (Mesovarium, Mesosalpinx, Mesometrium) · Ovarian ligament · Suspensory ligament of the ovary Recesses ♂: Recto-vesical pouch · Pararectal fossa ♀: Recto-uterine pouch · Recto-uterine fold (Uterosacral ligament) · Vesico-uterine pouch · Ovarian fossa · Paravesical fossa Lateral umbilical fold digestive system navs: anat of tract,glands,perit,diaphragm/physio/dev, noncongen/congen/congen of d+w/neoplasia, symptoms+signs/eponymous, proc

v • d • e Fetal vascular remnant ligaments (GA 6) Heart Ligamentum arteriosum Liver Round ligament of liver · Ligamentum venosum Umbilical Medial umbilical ligament (see also Median umbilical ligament and Lateral umbilical fold)

v • d • e Histology: connective tissue Classification Proper/ Fibrous Loose Areolar · Reticular non-fibrous: Adipose (Brown, White) Dense Dense irregular connective tissue (Submucosa, Dermis) · Dense regular connective tissue (Ligament, Tendon, Aponeurosis) Embryonic Mucous · Mesenchymal Specialized Cartilage · Bone · Blood Composition Extracellular matrix (noncellular) Ground substance Tissue fluid Fibers Reticular fibers: Collagen Elastic fibers: Fibrillin (FBN1, FBN2, FBN3) Cells Resident Fibroblast · Reticular cell · Tendon cell Adipocyte Chondroblast · Osteoblast Wandering cell Mast cell · Macrophage see also soft tissue integument, SF, LCT navs: anat/physio, noncongen/congen/neoplasia, symptoms+signs/eponymous, proc muscle, DF+DRCT navs: anat/hist/physio, acquired myopathy/congenital myopathy/neoplasia, symptoms+signs/eponymous, proc

ligaments attach bone to bone