CNS; VERTEBRAL COLUMN, SPINAL CORD

CNS; VERTEBRAL COLUMN, SPINAL CORD AND SPINAL NERVES

1. NAME: NANDINI SHAW ROLL NO:64 1 ST YEAR/MBBS/ESIC GULBARGA PHYSIOLOGY SEMINAR

2. TOPIC 1. VERTEBRAL COLUMN 2. SPINAL CORD 3. SPINAL NERVE

3. ABOUT VERTEBRAL COLUMN Also called spine, spinal column or backbone Composed of series of bones called vertebrae About 71 cm (28inch) : In adult male About 61cm (24 inch): In adult female Total number of vertebrae during early development is 33. But adults have only 26 vertebrae as sacrum and coccyx bones becomes fused.

4. REGIONS OF VERTEBRAL COLUMN 7 Cervical vertebrae (C1-C7) 12 Thoracic vertebrae (T1-T12) 5 Lumbar vertebrae (L1-L5) 1 Sacrum (5 Fused) 1 Coccyx (4 Fused)

5. FUNCTION OF VERTEBRAL COLUMN Supports the head Enclose and protect spinal cord Serve as point of attachment to ribs, pelvic girdle and muscles of back and upper limb. Absorbs shock Permits movement

6. ABOUT SPINAL CORD Cylindrical in shape. Extends from foramen magnum:L1/L2 (adult) Terminates between L1-L2 Connected to 31 pairs of spinal nerves. Not uniform in diameter throughout length. CNS SPINAL CORD BRAIN

7. ABOUT SPINAL CORD Tapered end is called conus medullaris (L1-L2). Cervical Enlargement (C5-T1): supplies lower limbs. Lumbar enlargement (L2-S3): supplies lower limbs.

8. ABOUT SPINAL CORD There are gray matter and white matter present in the spinal cord. Two relationship as we descend down from cervical to coccygeal region i.e. the white matter decreases and the gray matter increases.

9. SPINAL MENINGES Spinal cord is surrounded by 3 meninges: Duramater: Outermost layer, continuous with epineurium of spinal nerves. Arachnoid matter: Delicate network of collagen and elastic fibres. Pia mater: Thin layer of elastic and collagen fibres tightly bound to surface of brain and spinal cord.

10. CROSS SECTION OF SPINAL CORD Posterior median sulcus and posterior gray horn present in posterior portion. Anterior median fissure and anterior gray horn in the anterior surface. The white columns present are named with respect to gray matter. Posterior white column called dorsal funiculus, lateral column called lateral funiculus and ventral called ventral funiculus.

11. CROSS SECTION OF SPINAL CORD Some bulbs coming off from the sides in between posterior and ventral gray horns called lateral gray horns. It consists of preganglionic motor neurons of sympathetic nervous system.

12. FUNCTION OF SPINAL CORD The spinal cord transmits signals from the human brain to the rest of the system and also from remainder of the entire body to the mind.  The spinal cord possibly mediates the  PNS. The spinal cord perhaps manages autonomic functions.

13. ABOUT SPINAL NERVE The nerves coming out between the vertebrae are called spinal nerve. Path of communication between spinal cord and body. Mixed nerve carrying motor, sensory and autonomic signals between spinal cord and body.

14. SEGMENTS OF SPINAL NERVE Cervical segment: 8 pairs of spinal nerves Thoracic segment: 12 pairs of spinal nerves. Lumbar segment: 5 pairs of spinal nerves. Sacral segment: 5 pairs of spinal nerves. Coccygeal segment: 1 pair of spinal nerve. Therefore, total 31 pairs of spinal nerves are there. The first cervical spinal nerve is the only spinal nerve that exits above its respective vertebrae.

15. SPINAL NERVE Cauda equina : Spinal nerve extending from L2 to coccygeal . It has 2 connection to spinal cord: posterior/dorsal root and anterior/ventral root. They unite to form spinal nerve at intervertebral foramina. Post. Root contain post. r oot ganglion where cell bodies of sensory neuron is located.

16. SPINAL NERVE & FUNCTIONS From the root, a spinal nerve divides into several branches. These branches are called rami ; post. (dorsal) ramus and anterior (ventral) ramus . Dorsal ramus serve the deep muscles and skin of the post. Surface of the trunk. Anterior ramus serve muscles of upper and lower limbs.

17. :SOME OF THE SOURCES: BDC Gross Anatomy G.K.Pal Physiology https://functionsof.org/functions-of-spinal-cord/ https://revhc.ca/what-vertebrae-are-responsible-for-what-ask-a-chiropractor/ Profound gratitude to the Department of Physiology, ESIC Medical College Gulbarga