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]
- 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".
- 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.
Peritoneal ligaments[]
Certain folds of peritoneum are referred to as ligaments.
Examples include:
- The hepatoduodenal ligament surrounds the hepatic portal vein and other vessels as they travel from the duodenum to the liver.
- 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[]
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.
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 Wrist#Ligaments
Other[]
References[]
External links[]
Joints and ligaments of Head and Neck | |
---|---|
Atlanto-axial |
anterior atlantoaxial ligament - posterior atlantoaxial ligament - cruciform ligament of atlas (transverse ligament of the atlas) |
Atlanto-occipital |
anterior atlantoöccipital membrane - posterior atlantoöccipital membrane - tectorial membrane - alar ligament - ligament of apex dentis |
Temporomandibular |
capsule - temporomandibular ligament - sphenomandibular ligament - stylomandibular ligament - articular disk |
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 |
proximal radioulnar, humeroradial, humeroulnar: ulnar collateral - radial collateral - annular - oblique cord |
Forearm |
distal radioulnar: volar radioulnar - dorsal radioulnar wrist/radiocarpal: palmar radiocarpal - dorsal radiocarpal - ulnar collateral - radial collateral |
Hand |
intercarpal, midcarpal: pisohamate ligament - pisometacarpal ligament carpometacarpal: dorsal carpometacarpal - palmar carpometacarpal intermetacarpal: deep transverse metacarpal - superficial transverse metacarpal metacarpophalangeal, interphalangeal |
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 |
Sternocostal |
interarticular sternocostal ligament - radiate sternocostal ligaments - costoxiphoid ligaments |
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 |
iliofemoral - pubofemoral - ischiofemoral - head of femur - transverse acetabular |
Knee-joint |
patellar - popliteal (oblique, arcuate) - collateral (medial/tibial, lateral/fibular) - cruciate (anterior, posterior) - menisci (medial, lateral) |
Tibiofibular |
Superior tibiofibular: anterior of the head of the fibula - posterior of the head of the fibula |
Talocrural/ankle |
deltoid - external lateral of the ankle-joint (anterior talofibular, posterior talofibular, calcaneofibular) |
Foot - intertarsal |
Subtalar/talocalcaneal: anterior talocalcaneal - posterior talocalcaneal - lateral talocalcaneal - medial talocalcaneal - interosseous talocalcaneal |
Foot - other |
Cuneonavicular, Cuboideonavicular, Intercuneiform and cuneocuboid, Tarsometatarsal/Lisfranc, Intermetatarsal, Metatarsophalangeal, Interphalangeal |
Peritoneal ligaments, mesenteries, and folds | |
---|---|
Lesser omentum |
Hepatoduodenal ligament - Hepatogastric ligament |
Greater omentum |
Gastrophrenic ligament - Gastrocolic ligament - Gastrosplenic ligament |
Liver |
Falciform ligament (Round ligament of liver, Ligamentum venosum) - Coronary ligament (Left triangular ligament, Right triangular ligament, Hepatorenal ligament) |
Uterus/ovaries |
Broad ligament of the uterus (Mesovarium, Mesosalpinx, Mesometrium) - Ovarian ligament - Suspensory ligament of the ovary |
Other ligaments |
Splenorenal ligament - Phrenicocolic ligament - Pulmonary ligament |
Mesentery |
Transverse mesocolon - Sigmoid mesocolon - Mesoappendix |
Folds |
Umbilical folds (Supravesical fossa, Medial inguinal fossa, Lateral inguinal fossa) - Ileocecal fold |
Recesses |
Rectouterine pouch - Vesicouterine excavation - Rectovesical excavation - Pararectal fossa - Paravesical fossa |
Peritoneal cavity |
Greater sac - Lesser sac - Foramen of Winslow |