The Anatomy of Spinal Cord

Assalamualaikum everyone,
Here is the full curriculum of Anatomy of Spinal Cord Injury. This presentation was made by me at my student life where I have done a lot of researchs, findings and notes.
Please correct me if you find anything wrong by a responsive comment !
I wish you all the very best!

1. Anatomy of pinal Cord

2. Welcome to our presentation Presented By: Nafisa Maliaut Eshamoni, Roll: 01 MD. Risalat-Ul-Huda, Roll: 03 3 rd Batch, Dept. BSc in Physiotherapy, IIHS Supervised By: Md. Muzaffor Hossain Incharge and Senior Clinical Physiotherapist, SCI Department, CRP Topic : Anatomy of Spinal Cord

3. Let’s Learn About…. Contents : Introduction Spinal Cord – Anatomy Classification Gross anatomy of Spinal Cord Features – External and Internal Spinal Canal Covering of Spinal cord Spinal Nerve Blood Supply Tracts of Spinal cord Summary Acknowledgement

4. Learning Outcomes At the end of the lecture, students should be able to: • Describe the external anatomy of the spinal cord. • Describe the internal anatomy of the spinal cord. • Describe the spinal nerves: formations, branches and distribution via plexuses. • Describe the meninges of the spinal cord. • Define a reflex and reflex arc, and describe the components of the reflex arc.

5. How can we Classify Anatomy of any parts of our Body ?

6. What is Spinal Cord? Definition: The spinal cord is part of the Central Nervous System and consists of a tightly packed column of nerve tissue that extends downwards from the brainstem through the central column of the spine. Weight: 35 g (av.) Diameter: 1-1.5 cm Length: 40-50 cm long, in an adult The spinal cord carries nerve signals from the brain to other parts of the body and receives sensory input from the body, partially processes it, and then transmits that information to the brain.

7. Features Spinal Cord: External Externally, the spinal cord is protected by 33 vertebrae, which sit between a semi-rigid intervertebral disc, which provide a level of flexibility to the vertebral column. Its flexibility is greatest in the cervical region and lowest in the thoracic region. The spinal cord (similar to the brain) is protected by three layers of meninges (membranes). The spinal cord extends from the foramen magnum to the lowest border of the first lumbar vertebra. It is enlarged at two sites, the cervical and lumbar region. The vertebrae (in adults) are arranged in five regions, which provide support and protection for the spinal cord .   It consists of seven Cervical Vertebrae, twelve Thoracic Vertebrae, five Lumbar Vertebrae, five Sacral (fused in adults to form the sacrum) and four Coccygeal Vertebrae (fused to form the coccyx).

8. Spinal Cord: Internal Inside, the spinal cord consists of grey matter and white matter. The grey matter takes on the shape of a butterfly, with four 'wings' called horns: The horns in the front contain motor neurons; the horns in the back contain sensory neurons which carry sensory information. The spinal cord grey matter is surrounded by a column of white matter, containing axons that allow different parts of the spinal cord to communicate smoothly, with signals passing upwards and downwards conveying e.g. sensation and motor signals. Entry and Exit Sensory Nerve Fibers enter the Spinal Cord via the Posterior (Dorsal) Root. The cell bodies for these neurons are situated in the Dorsal Root Ganglia. Motor and Preganglionic Autonomic Fibers exit via the Anterior (Ventral) Root.

9. Structure : Spinal Cord The spinal cord is the major conduit and reflex center between the peripheral nerves and the brain and transmits motor information from the brain to the muscles, tissues and organs, and sensory information from these areas back to the brain.  It is, cylindrical and slightly flattened anteriorly and posteriorly. Its upper end is continuous with the medulla, the transition is defined to occur just above the level of exit of the first pair of cervical nerves. Its tapering lower end , the conus medullaris, terminates at the level of the L3 vertebra in neonates, and at the level of the L1-2 intervertebral disk in adults. It then becomes the cauda equine The cauda equine Is the name given to the roots of the spinal nerves that extend beyond the termination of the spinal cord at the first lumbar vertebra in the form of a bundle of filaments within the spinal canal resembling a horse's tail. 

10. Spinal Canal Formed by the vertebral foramina of the vertebral bodies the spinal canal [bound anteriorly by the vertebral bodies and posteriorly by the laminae (vertebral arches)] with reinforcement at the walls through the intervertebral disks and the anterior and posterior longitudinal ligament. The diameter varies from 12 to 22 mm in the cervical region and from 22 to 25 mm in the lumbar region. Contains:  1. Spinal cord 2. Meninges 3. Blood vessels 4. Spinal nerve roots and surrounding fatty and  connective tissues.

11. Spinal Nerves The term spinal nerve generally refers to a mixed spinal nerve that carries motor, sensory, and autonomic signals between the spinal cord and the body. Humans have 31 left–right pairs of spinal nerves, each roughly corresponding to a segment of the vertebral column. There are eight cervical, twelve thoracic, five lumbar, five sacral and one coccygeal. The spinal nerves are relatively large nerves that are formed by the merging of two nerve roots: a sensory nerve root and a motor nerve root. Sensory nerve roots emerge from the back of the spinal cord and the motor nerve roots from the front of the spinal cord. As they join, they form the spinal nerves on the sides of the spinal cord. The anterior and posterior roots join to form two spinal nerves, one on either side of the spine, which then exit the vertebral canal through the intervertebral foramina. Once outside the intervertebral foramina they form peripheral nerves.  While there are eight pairs of cervical spinal nerves there are only seven cervical vertebrae. This disparity occurs because the first pair of cervical spinal nerves exits  above  the first cervical vertebra just below the skull. However, the eighth pair of cervical spinal nerves exits  below  the last cervical vertebra.

12. Spinal Nerves

13. Spinal Motor neurons  

14. Blood Supply of Spinal Cord The majority of the spinal cord blood supply is provided by the segmental spinal arteries, with further supply coming from the vertebral arteries via a single anterior spinal artery and paired posterior spinal arteries. The segmental and spinal arteries are linked by numerous anastomoses.   Segmental Arteries:   The segmental arteries give off radicular branches, cervical and thoracolumbar, which enter the intervertebral foramen and supply the anterior and posterior roots and spinal ganglion of the corresponding level. Spinal Arteries:  The spinal arteries, arising from the vertebral artery, run longitudinally down the spinal cord. It is further divided as anterior and posterior spinal artery. Spinal Veins:   Blood from within the spinal cord travels through the intramedullary veins, to the anterior and posterior spinal veins, which form a reticulated network in the pia mater around the circumference of the cord throughout its length.

15. Figure : Blood Supply and Arterial Supply of spinal cord

16. Figure: Spinal Nerve and the blood supply

17. Anatomy of Spinal Nerve

18. Dorsal Rami

19. Ventral Rami

20. Plexus

21. Cervical Plexus

22. Brachial Plexus

23. Lumbar Plexus

24. Sacral Plexus

25. Tracts of Spinal Cord

26. Get your Spines Straight and Ask your question!

27. References A Textbook of Spinal Cord Injury and Management – Md. AK Hasnat (1 st Ed) 2.  Jump up to:2.0   2.1   2.2   2.3   2.4   2.5   2.6   2.7  Rohkamm Reinhard. Color Atlas of Neurology. Thieme; 2014 Sep 2. 3. Spinal Cord.  Blausen Medical . Retrieved on 26 January 2016. 4.  Jump up to:4.0   4.1   4.2   4.3   4.4   4.5   4.6   4.7  Moore KL, Agur AM, Dalley AF. Essential Clinical Anatomy. Philadelphia: Lippincott Williams & Wilkins; 2002 Mar. 5. Francisco de Assis Aquino Gondim et al., Topographic and Functional Anatomy of the Spinal Cord, Medshape, 2015 6. Merriam webster Cauda equina Available: https://www.merriam-webster.com/medical/cauda%20equina  (accessed 29.4.2022) 7. Healthline Cauda equina Available:  https://www.healthline.com/human-body-maps/cauda-equina#1 (accessed 29.4.2022) 8. Very well health Spinal Nerves Available: https://www.verywellhealth.com/spinal-nerves-anatomy-4682599  (accessed 29.4.2022) 9.  Jump up to:1.0   1.1  Designed by Freepik at  http://www.freepik.com

28. Acknowledgement I would like to express my special thanks of gratitude to our honorable Dr. Mohammad Anwar Hossain Sir, honorable Md. Muzaffor Hossain Sir as well as the Faculty members and respected teachers who gave us this golden opportunity to do this wonderful project on the topic “Anatomy of Spinal Cord”, which helped us in doing a lot of research and we come to know so many new things. Special Thanks to my very own institute International Institute of Health Sciences for sending us here in CRP to explore out of boundaries. Thanks again for all your support !

29. Gratitude !