Golgi tendon organ
| Golgi tendon organ | |
|---|---|
Musculoskeletal system | |
| Location | Skeletal muscle |
| Identifiers | |
| Latin | organum sensorium tendinis |
| TH | H3.03.00.0.00024 |
| Anatomical terms of microanatomy] | |
The Golgi tendon organ (GTO) (also called Golgi organ, tendon organ, neurotendinous organ or neurotendinous spindle) is a
The Golgi tendon organ is one of several eponymous terms named after the Italian physician Camillo Golgi.
Structure
The body of the Golgi tendon organ is made up of braided strands of collagen (intrafusal fasciculi) that are less compact than elsewhere in the tendon and are encapsulated.[2]
The capsule is connected in series (along a single path) with a group of muscle fibers (10-20 fibers[3]) at one end, and merge into the tendon proper at the other.
Each capsule is about 1
Function
When the muscle generates force, the sensory terminals are compressed. This stretching deforms the terminals of the Ib afferent axon, opening stretch-sensitive
The Ib sensory feedback generates stretch reflexes and supraspinal responses which control muscle contraction. Ib afferents synapse with interneurons in the spinal cord that also project to the brain cerebellum and cerebral cortex. The Golgi tendon reflex assists in regulating muscle contraction force. It is associated with the Ib. Tendon organs signal muscle force through the entire physiological range, not only at high strain.[7][8]
During locomotion, Ib input excites rather than inhibits motoneurons of the receptor-bearing muscles, and it affects the timing of the transitions between the stance and swing phases of locomotion.[9] The switch to autogenic excitation is a form of positive feedback.[10]
The ascending or afferent pathways to the cerebellum are the dorsal and ventral spinocerebellar tracts. They are involved in the cerebellar regulation of movement.[citation needed]
History
Until 1967 it was believed that Golgi tendon organs had a high threshold, only becoming active at high muscle forces. Consequently, it was thought that tendon organ input caused "weightlifting failure" through the clasp-knife reflex, which protected the muscle and tendons from excessive force. [citation needed] However, the underlying premise was shown to be incorrect by James Houk and Elwood Henneman in 1967.[11]
See also
- Golgi–Mazzoni corpuscles
Footnotes
Sources
This article incorporates text in the public domain from page 1061 of the 20th edition of Gray's Anatomy (1918)
- ISBN 0736045171.
- ISBN 978-1-4160-4705-6.
- ^ a b Purves et al (2018), Mechanoreceptors Specialized for Proprioception, pp. 201-202
- ^ a b Pearson & Gordon (2013), 35-3 Golgi Tendon Organs, p. 800
- ^ Saladin (2018), The Tendon Reflex, p. 498-499
- ISBN 978-0-07-160567-0.
- ^ PMID 9490855.
- PMID 1177014.
- S2CID 22961186.
- PMID 9212270.
- PMID 6037588.
Other sources
- Saladin, KS (2018). "Chapter 13 - The Spinal Cord, Spinal Nerves, and Somatic Reflexes". Anatomy and Physiology: The Unity of Form and Function (8th ed.). New York: McGraw-Hill. ISBN 978-1-259-27772-6.
- Purves, Dale; Augustine, George J; Fitzpatrick, David; Hall, William C; Lamantia, Anthony Samuel; Mooney, Richard D; Platt, Michael L; White, Leonard E, eds. (2018). "Chapter 9 - The Somatosensory System: Touch and Proprioception". Neuroscience (6th ed.). Sinauer Associates. ISBN 9781605353807.
- Pearson, Keir G; Gordon, James E (2013). "35 - Spinal Reflexes". In Kandel, Eric R; Schwartz, James H; Jessell, Thomas M; Siegelbaum, Steven A; Hudspeth, AJ (eds.). Principles of Neural Science (5th ed.). United States: McGraw-Hill. ISBN 978-0-07-139011-8.
External links
Media related to Golgi tendon organ at Wikimedia Commons
