Three layers of membranes known as meninges protect the brain and spinal cord. The delicate inner layer is the pia mater. The middle layer is the arachnoid, a web-like structure filled with fluid that cushions the brain. The tough outer layer is called the dura mater. The cerebral ventricular system is made up of 4 ventricles that include 2 lateral ventricles (1 in each cerebral hemisphere), the third ventricle in the diencephalon, and the fourth ventricle in the hindbrain. Inferiorly, it is continuous with the central canal of the spinal cord.

1. Topic- Meninges, Ventricle Of Brain
And Electrophysiology Of Nervous
System
Presented By:-
Lovish Bangarh
B.Pharm 1st Year
Submitted to-Ms.Sapna Assist.Professor
MMCP

2. MENINGES
 Three thin layers of tissue that cover and protect the brain as well as spinal cord.
 Meninges provide both protection and
nourishment to brain and spinal cord.
 Three layers of meninges:
• Dura Matter
• Arachnoid Matter
• Pia Matter

3. Dura Matter
 Toughest and outermost layer
 Further divided into two sub layers:
o Endosteal layer
o Meningeal layer
Arachnoid Matter
 Middle fibrous layer
 Separated from dura matter by
subdural space
 Separated from pia matter by
subarachnoid space
 Arachnoid and pia matter are collectively
known as Leptomeninges

4. Pia Matter
 Inner most layer of meninges
 Highly vascular connective tissue layer
 Carry blood vessels into the brain
 Plays major role in formation of Choroid Plexus

6. Meningitis
 Meningitis is an inflammation (swelling) of the protective membranes
covering the brain and spinal cord.
 A bacterial or viral infection of the fluid surrounding the brain and spinal
cord usually causes the swelling.
 However, injuries, cancer, certain drugs, and other types of infections also
can cause meningitis. It is important to know the specific cause of
meningitis because the treatment differs depending on the cause.

8. Ventricles of Brain
 The ventricles are cavities(hollow spaces) filled with
Cerebrospinal fluid.
 There are four ventricles in our brain that are interconnected
to each other.
 Each ventricle is lined by ependymal cells which forms
Choroid Plexus that produces Cerebrospinal fluid.

9. Four ventricles of brain
 Right lateral ventricle
 Left lateral ventricle
 Third ventricle
 Fourth ventricle

11. Disorders of Ventricles
 Hydrocephalus- is the buildup of fluid in cavities called ventricles deep within
the brain. The excess fluid increases the size of the ventricles and puts pressure on
the brain.
 It is also known as Ventriculomegaly.

12. Electrophysiology of Neurons
 Most important function of nerve cells are Irritability and Conductivity.
 Irritability- is the property of neuron by which it response to a stimulus and
change it into impulse.
 Conductivity- is the property of a neurone by which it transmit impulse to the
muscle gland or other neurons.

13. Overview of Nerve Impulse
 Resting potential- Neuron is not stimulated at threshold level
 Action Potential- Neuron respond to stimulus, send message along axon.
1. Depolarisation
2. Repolarisation
**Potential=difference in charge(measured in volts)

14. Resting Potential
 Inactive neuron
 Inside cell membrane more = K+ ions
 Outside cell membrane more = Na+ ions
 This condition also called as polarised cell membrane.
 The RMP is about -70mv and the neuron having a resting potential is in the
polarized state.
 At this state the membrane is less permeable to Na+

15. Action Potential
 Active neuron
 When stimulated, the permeability of the nerve cell membrane to these ions
change.
 Initially Na+ floods into the neuron from the extracellular fluid and when
stimulates reach to -55mv(threshold level) so voltage gated channel

17. 1. Polarisation Phase
RMP(-70mV) occurs when the inner lining of cell membrane has more anions and
the outer lining has more cations.
2. Depolarisation phase
When cell membrane receive a threshold stimulus so membrane permeability for Na+
ions increased. Na+ channels open and Na+ ions enter inside the cell which cause
Depolarisation.
3. Repolarisation Phase
After the Na+ ions channel closed and K+ channel ion open so K+ ion outs from the cell
And cause repolarization.

19. 4. After hyperpolarising phase
The K+ ions continuously out from the cell in a slow rate even after the RMP is reached
That cause repolarization.
After some time K+ channel also close and sodium potassium pump and the leak channels
(k+, Cl-) bring the final ionic distribution to the resting state.