Meninges, ventricle and CSF

Nervous system-Meninges, ventricle of brain and CSF

1. Human Anatomy and Physiology-II Nervous system ( Organization of Nervous system, Meninges , Ventricle and CSF) Mr N.JEGAN Associate Professor K.M.COLLEGE OF PHARMACY. MADURAI.

2. T opic 1.Organization of Nervous system 2. Meninges 3. Ventricle of Brain 4.Cerebrospinal fluid (CSF)

3. Organization of Nervous system

4. Nervous system is divided into two parts: 1. Central nervous system 2. Peripheral nervous system.

5. Central nervous system- It is composed of two major inter connected organs Brain Spinal cord 2. Peripheral nervous system.- It is composed of Cranial nerve Spinal nerve Peripheral nerve It contain- Sensory neuron and Motor neuron.

6. Central nervous system Central nervous system (CNS) includes brain and spinal cord. Structures of brain and spinal cord are arranged in two layers, namely Gray matter white matter .

7. Meninges

8. Meninges The brain and spinal cord are completely surrounded by three membranes, the meninges It lying between the skull and the brain and between the vertebrae and the spinal cord. They are 1.Dura mater 2.Arachnoid mater 3. Pia mater

9. Dura mater The cerebral dura mater consists of two layers of dense fibrous tissue . There is only a potential space between the cerebral hemispheres to form the falx cerebri between the cerebellar hemispheres to form the falx cerebelli between the cerebrum and cerebellum to form the tentorium cerebelli

10. Arachnoid mater Serous membrane lies between the dura and pia maters It continues downwards to envelop the spinal cord and ends by merging with the dura mater

11. Pia mater This is a fine connective tissue containing many minute blood vessels. It adheres to the brain, completely covering each fissure of brain. It continues downwards surrounding the spinal cord. Beyond the end of the cord it continues as the filum terminale

12. Meninges -Space 1.The dura and arachnoid maters are separated by a potential space, the subdural space. 2. The arachnoid and pia maters are separated by the subarachnoid space, containing cerebrospinal fluid.

13. Ventricle of Brain

14. Ventricles of brain Within the brain there are four irregular-shaped cavities, or ventricles, containing cerebrospinal fluid (CSF). They are: 1.Right lateral ventricles 2.Left lateral ventricles 3. Third ventricle 4.Fourth ventricle

15. The lateral ventricles These cavities lie within the cerebral hemispheres , one on each side of the median plane just below the corpus callosum . They communicate with the third ventricle by interventricular foramina.

16. Third ventricle The third ventricle is a cavity situated below the lateral ventricles between the two parts of the thalamus. It communicates with the fourth ventricle by a canal, the cerebral aqueduct or aqueduct of the midbrain.

17. Fourth ventricle The fourth ventricle is a diamond-shaped cavity situated below and behind the third ventricle, between the cerebellum and pons . It is continuous below with the central canal of the spinal cord and communicates with the subarachnoid space by foramina in its roof.

18. Cerebrospinal fluid (CSF)

19. Cerebrospinal fluid (CSF) Cerebrospinal fluid (CSF) is the clear, colorless and transparent fluid that circulates through ventricles of brain , subarachnoid space and central canal of spinal cord.

20. PROPERTIES AND COMPOSITION Volume : 150 mL (100 mL to 200 mL ) Rate of formation : 0.3 mL per minute Composition It mainly contain Lymphocyte

21. FORMATION OF CEREBROSPINAL FLUID Cerebrospinal fluid is secreted into each ventricle of the brain by choroid plexuses. Choroid plexuses are tuft of capillary projections present inside the ventricles and are covered by pia mater and ependymal covering. CSF passes back into the blood through tiny diverticula of arachnoid mater, called arachnoid villi ( arachnoid granulations), that project into the venous sinuses.

22. Functions of CSF 1.It supports and protects the brain and spinal cord. 2. It maintains a uniform pressure around these delicate structures. 3. It acts as a cushion and shock absorber between the brain and the cranial bones. 4. It keeps the brain and spinal cord moist and there may be interchange of substances between CSF and nerve cells, such as nutrients and waste products.

23. Thank you