In anatomy, the term ligament is used to denote three different types of structures:[1]
- Fibrous tissue that connects bones to other bones. They are sometimes called "articular ligaments"[2], "fibrous ligaments", or "true ligaments".
- A fold of peritoneum or other membrane
- 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).
Peritoneal ligaments
Certain folds of peritoneum are referred to as ligaments.
Examples include:
- The broad ligament of the uterus is also a fold of peritoneum.
- The suspensory ligament of the ovary
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
|
Articular ligaments
Diagrammatic section of a symphysis.
In its most common use, a ligament is a short band of tough fibrous dense regular connective tissue composed mainly of long, stringy collagen 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.
Ligaments are only 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 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.
Examples:
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
Head and neck
- Cricothyroid ligament
- Periodontal ligament
- Suspensory ligament of the lens
Pelvis
- Anterior sacroiliac ligament
- Posterior sacroiliac ligament
- Sacrotuberous ligament
- Sacrospinous ligament
- Inferior pubic ligament
- Superior pubic ligament
- Suspensory ligament of the penis
Thorax
- Suspensory ligament of the breast
Wrist
See also
References
ISBN links support NWE through referral fees
- ↑ Template:EMedicineDictionary
- ↑ Template:DorlandsDict
External links
| Joints and ligaments of head and neck |
|---|
| | Craniocervical |
| Atlanto-axial (lat + med) |
capsule - atlantoaxial ligaments (anterior, posterior) - cruciform ligament of atlas (transverse ligament of the atlas) |
| Atlanto-occipital |
capsule - membranes (anterior atlantoöccipital membrane - posterior atlantoöccipital membrane - tectorial membrane)
alar ligament - ligament of apex dentis |
| | | Temporomandibular | capsule - articular disk
lateral (temporomandibular ligament) - medial (sphenomandibular ligament, stylomandibular ligament) | | | Other | Cricothyroid articulation - Cricoarytenoid articulation |
|
| Joints and ligaments of upper limbs |
|---|
| | Shoulder |
| Sternoclavicular |
Anterior sternoclavicular · Posterior sternoclavicular · Interclavicular · Costoclavicular |
| Acromioclavicular |
Acromioclavicular · Coracoclavicular (trapezoid, conoid) · Coracoacromial · Superior transverse scapular · Inferior transverse of scapula |
| Glenohumeral |
Coracohumeral · Glenohumeral (superior, middle, and inferior) · Transverse humeral · Glenoid labrum |
| | | Elbow |
| Humeroradial |
Radial collateral |
| Humeroulnar |
Ulnar collateral |
| Proximal radioulnar |
Annular · Oblique cord |
| | | Forearm |
| Distal radioulnar |
Volar radioulnar · Dorsal radioulnar |
| Wrist/radiocarpal |
Palmar radiocarpal · Dorsal radiocarpal · Palmar ulnocarpal · Ulnar collateral · Radial collateral |
| | | Hand |
| Intercarpal, midcarpal |
Pisohamate · Scapholunate |
| Carpometacarpal |
Dorsal carpometacarpal · Palmar carpometacarpal (pisometacarpal) |
| Intermetacarpal |
Deep transverse metacarpal · Superficial transverse metacarpal |
| Metacarpophalangeal |
Palmar · Collateral |
| Interphalangeal |
Palmar · Collateral |
|
|
| Joints and ligaments of torso |
|---|
| | Vertebral column | articulations of vertebral bodies: anterior longitudinal ligament - posterior longitudinal ligament - intervertebral disc (annulus fibrosus, nucleus pulposus)
articulations of vertebral arches : ligamenta flava - supraspinous ligament (nuchal ligament) - interspinal ligament - intertransverse ligament
zygapophysial joint | | | Costovertebral | articulation of head of rib: radiate ligament - interarticular ligament
costotransverse | | | Sternocostal | interarticular sternocostal ligament - radiate sternocostal ligaments - costoxiphoid ligaments
interchondral, costochondral | | | Pelvis | articulation of the vertebral column with the pelvis: iliolumbar ligament
sacroiliac: anterior sacroiliac ligament - posterior sacroiliac ligament - interosseous sacroiliac ligament
ligaments connecting the sacrum and ischium: sacrotuberous ligament - sacrospinous ligament
sacrococcygeal symphysis: anterior sacrococcygeal ligament - posterior sacrococcygeal ligament
pubic symphysis: superior pubic ligament - inferior pubic ligament |
|
| Joints and ligaments of lower limbs |
|---|
| | Coxal/hip | femoral (iliofemoral, pubofemoral, ischiofemoral) - head of femur - transverse acetabular | | | Knee-joint | extracapsular: patellar - popliteal (oblique, arcuate) - collateral (medial/tibial, fibular/lateral)
intracapsular: cruciate (anterior, posterior) - menisci (medial, lateral) - transverse | | | 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 |
| | | 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) | | | Foot |
| 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 |
|
|
| Peritoneal ligaments, mesenteries, and folds |
|---|
| | 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 | | | Uterus/ovaries | Broad ligament of the uterus (Mesovarium, Mesosalpinx, Mesometrium) - Ovarian ligament - Suspensory ligament of the ovary | | | Folds | Umbilical folds (Supravesical fossa, Medial inguinal fossa, Lateral inguinal fossa) - Ileocecal fold - Rectouterine folds | | | Recesses | Rectouterine pouch - Vesicouterine excavation - Rectovesical excavation - Pararectal fossa - Paravesical fossa | | | Peritoneal cavity | Greater sac - Lesser sac - Foramen of Winslow |
|
| Fetal vascular remnant ligaments |
|---|
| | Heart | Ligamentum arteriosum | | | Liver | Round ligament of liver - Ligamentum venosum | | | Umbilical | Medial umbilical ligament (see also Median umbilical ligament and Lateral umbilical ligament) |
|
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