T5–T6 nucleus !
The nucleus pulposus is the soft, gel-like centre of the T5-T6 disc in the mid-back; it works like a water cushion that spreads the load.
Official name: T5-T6
Opens in the Durgical app, no sign-up needed.
What it is
The soft, gel-like centre (nucleus pulposus) of the T5–T6 disc.
What it does
Works like a water cushion: it turns pressure from above into outward push on the fibre ring, spreading the load. It is under the most pressure when you bend forward and lift.
Key facts
- Where
- Centre of the T5–T6 disc, slightly toward the back, inside the annulus fibrosus
- Function
- Notochord-derived gel (about 70–90% water, proteoglycans); turns axial load into annulus tension; small in thin thoracic discs, herniation rare
Relations
- Behind
- Back of the annulus fibrosus and the posterior longitudinal ligament, then the spinal cord
Examination
- Vibration and joint position sense in the toes, with the Romberg test: their loss suggests that cord compression is affecting the dorsal columns
On imaging
Calcium in the nucleus or in a herniated fragment shows on CT as dense white material; MRI can underestimate it.
Common problems
- Squeezes out through a tear in the ring (herniation), usually backward and to one side, toward a nerve root.
- Loses water with age, so the disc gets thinner and stiffer.
How it is diagnosed
On MRI a healthy nucleus is bright on T2 images; a worn one turns dark ('black disc').
Treatment
- In a microdiscectomy only the loose piece that has pushed out is removed; most of the disc stays.
Clinical notes
- Thoracic disc myelopathy is often recognised late, because early stiffness, heavy legs or vague band pain is put down to other causes
- Loss of vibration and position sense in the legs also occurs in vitamin B12 deficiency and multiple sclerosis, which are ruled out when MRI shows no cord compression
Development
Notochord remnants left in the spine can give rise to a chordoma, a slow-growing malignant tumour; most arise in the sacrum or at the skull base, and few in the mobile spine.
Test yourself
Think of the answer, then tap the question to see it.
What does a central fragment of the T5–T6 nucleus press on?
The spinal cord rather than a root; the mid-thoracic canal has little room to spare.
Which imaging best shows calcium in the T5–T6 nucleus or a herniated fragment?
CT, where it shows as dense white material; MRI can underestimate it.
From which embryonic structure does the T5–T6 nucleus pulposus come?
The notochord: the nucleus is a notochord-derived gel, rich in water and proteoglycans.
Educational information, not medical advice. For any symptom, see a health professional.
Its names
- Official Latin (TA2)
- nucleus pulposus T5-T6 TA2 1686
- Official Spanish (DeCS)
- Núcleo pulposo T5-T6 DeCS D000070614
- English (TA2)
- T5-T6
Related
Sources: Terminologia Anatomica (TA2); DeCS; Anatomy, Back, Nucleus Pulposus; Anatomy, Back, Intervertebral Discs; 7.3 The Vertebral Column (OpenStax (Rice University), 2022) · adapted, CC BY 4.0; 7.5 Embryonic Development of the Axial Skeleton (OpenStax (Rice University), 2022) · adapted, CC BY 4.0.
Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake
Representative model, for educational purposes only.
