Ascending Spinal Tracts
Rahul's Noteblog
Notes on Neurology
Notes on The Spinal Cord
Ascending Spinal Tracts
Ascending Spinal Tracts:
1. Gracile fasciculus:
Terminate in the gracile nucleus (dorsal column).
2. Cuneate fasciculus:
Terminate in the cuneate nucleus (dorsal column). The two fasciculi are also termed the posterior column - medial lemniscal pathway. Both the fasciculus gracilis and cuneatus relay in the gracile and cuneate nuclei in the medulla oblongata respectively. The function of the posterior columns are directed at conscious proprioception and discriminative touch. Three orders of afferents carry the information from the sensory receptors to the somatic sensory cortex.
a. First order afferents: Information from the lower limb, hand and trunk are relayed from the sensory receptors (Meissner, Pacinian, Ruffini, Merkel Cell, Golgi tendon organs) is the two fasciculi. Fibres from the lower leg and trunk pass in the gracile fasciculi and upper limb in the cuneate fasciculus, respectively.
b. Second order neurons pass from the two nuclei (in medulla oblongata) cross over to the opposite side, enter the medial lemniscus, transverse the tegmentum (pons and midbrain), relay in the ventral posterolateral nucleus of the thalamus.
c. Third order neurons pass from the thalamus to the somatic sensory cortex of the cerebrum.
3. Anterior and posterior spinocerebellar tracts:
Cuneo-cerebellar and rostral spinocerebellar. Functions include relay of unconscious proprioception fibres.
4. Anterior and lateral spinothalamic tracts:
The latter is called the spinal lemniscus as it traversus the brainstem. The tracts carry fibres for temperature, touch and pain sensation.
5. Spinoreticular, spinotectal, spino-olivary tracts.
Chapters on Spinal Cord:
1. Anatomy of the Spinal Cord
2. Ascending Spinal Tracts
3. Blood Supply of Spinal Cord
4. Notes on Corticospinal Tracts
5. Cross Section of Spinal Cord
6. Descending Spinal Tracts
7. Grey Matter of Spinal Cord
8. Summary of Spinal Nerves
Additional Reading:
Basic Neurology
1. Peripheral Nervous System
2. Central Nervous System
3. The Ventricular System
4. The Spinal Cord
5. The Brain Stem
6. The Cerebellum
7. Visual Pathways
8. Diencephalon
9. Basal Ganglia
10. Cerebral Cortex
11. Sleep Disorders
12. Autonomic Nervous System
13. Cranial Nerves and Parasympathetic Ganglia
14. Cells of the Nervous System
15. Cerebrospinal fluid
16. Additional short notes on Cerebrum
17. Functions and Diseases of Cerebrum
18. Subcortical Grey Matter
19. Notes on The Spinal Cord
20. Regulation of Heart Rate by Autonomic Nervous System
21. Action Potentials, Axon Conduction, and Neuromuscular Junction
22. Types of Seizures
Neurology Videos
1. Video of Neurology Examination in a Clinical Setting
Medical Images
Useful Medical Images & Diagrams (link opens in a new window)
Related Topics
1. Nervous System Disorders
2. Histology of Nervous Tissue
3. Cranial Nerve Reflexes
4. Motor System Examination
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