Meninges of spinal cord

here we discuss about spinal cord and its meninges

1. Meninges Of Spinal Cord Content: Introduction to spinal cord Brief introduction to meninges. Meninges of spinal cord. Dura mater. Arachnoid mater Pia mater Clinical notes. MADE BY: AQSA KIRAN. CLASS: DPT-4(2018)

2. SPINAL CORD The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column . The brain and spinal cord together make up the central nervous system (CNS ). The spinal cord functions primarily in the transmission of nerve signals from the motor cortex to the body, and from the afferent fibers of the sensory neurons to the sensory cortex . The spinal cord is protected by three layers of tissue or membranes called meninges, that surround the canal .

3. Meninges The meninges is a layered unit of membranous connective tissue that covers the brain and spinal cord. These coverings encase central nervous system structures so that they are not in direct contact with the bones of the spinal column or skull . The term 'meninges' (singular: meninx) is derived from the Greek word for membrane. The meninges are composed of three membrane layers Dura mater. Arachnoid mater. Pia mater.

4. Functions of meninges Its primary function is to protect and support the central nervous system (CNS ). It connects the brain and spinal cord to the skull and spinal canal . The meninges forms a protective barrier that safeguards the sensitive organs of the CNS against trauma . It produces cerebrospinal fluid .

5. Meninges of spinal cord Spinal cord in vertebral column is protected by three layers of meninges. 1. Dura Mater 2. Arachnoid Mater 3. Pia Mater. The meningeal layer continuous above through the foramen magnum with the meningeal layer of dura covering the brain and ends on the filum terminale at the lower border of second sacral vertebra.

6. Dura mater It is the outer most meningeal covering of spinal cord. The spinal dura mater is only compose of Dural meningeal layer means unlike brain dura mater it do not have Dural periosteal layer. It forms the Dural sac that envelopes the cauda equine of the spinal cord and extends downward together with the filum terminale to the periosteum of the coccyx. Filum terminale: it is the thread of connective tissue and the point at which the spinal cord ends.

7. It is the thickest and toughest of all three layers. It derived from the mesoderm in the embryonic developments. The dura mater contributes to the subdural and epidural spaces. Subdural space: The space between dura mater and arachnoid mater is called subdural space. Epidural space: Dura mater is separated from the walls of the vertebral canal by the epidural space . This space contains some loose connective tissue, and the internal vertebral venous plexus . the spinal nerves exit the vertebral canal, they pierce the dura mater, temporarily passing in the epidural space.

8. Dural sheath An extension of the dura mater that surrounds the spinal nerves of the spinal cord . The Dural sheath extends beyond the end of the spinal cord, creating a cavity known as the lumbar cistern .

9. Arachnoid mater It is the middle layer of meninges inferior to dura mater and superior to pia mater. It is a delicate membrane , impermeable and avascular membrane. It is separated from the pia mater by subarachnoid space . subarachnoid space: I t contains the arachnoid trabeculae ( thin fibrous filaments that holds the two layer in there place. ) It is filled with CSF. It provides the pathway for CSF circulation and absorption. Roots of spinal roots, arteries and veins passes through this space.

10. Pia mater The spinal pia mater is the innermost of the meninges. It is a thin membrane that covers the spinal cord, nerve roots and their blood vessels. Inferiorly, the spinal pia mater fuses with the filum terminale . Between the nerve roots, the pia mater thickens to form the denticulate ligaments . It is the highly vascular layer. Ligamentum denticulatum passes laterally to adhere to the arachnoid and dura mater. Due to this the spinal cord is suspended in the middle of the Dural sheath.

11. Clinical notes Lumber punchers: The elongation of the spinal dura mater past the termination of spinal cord allows for the retrieval of cerebrospinal fluid from this area. This is known as lumber punchers. 2 . Meningitis: An inflammation of the meninges, the membranes that surround the spinal cord. Head ach: stretching of dura mater results in head ach.