What is Meninges?
- The Meninges are the membrane covering the Brain and Spinal cord.
- The Meninges consist of three membranes:
- The dura mater
- The arachnoid mater
- The pia mater
. Dura Mater
- It is a thick dense inelastic membrane and the outermost layer of the meninges
- It is bilaminar( consists of two-layer.
. 1. Endosteal layer( outer layer)
. 2. Meningeal layer( inner layer)
- These are closely united except along certain lines, where they separate to form venous sinuses.
- Dura mater septa
. 1. Falx cerebri
. 2. Falx cerebelli
. 3. Tentorium cerebelli
. 4. Diapharagma sellae
Dural Nerve Supply
- Branches of the Trigeminal, Vagus and first three Cervical nerves and branches from the sympathetic system pass to the dura
- The dura is sensitive to stretching which produces the sensation of headache.
Dural Blood Supply
- Dura mater's arteries supply from the internal carotid, maxillary, ascending pharyngeal, occipital and vertebral arteries.
- It drains by the Meningeal vein lie in the endosteal layer of the dura.
- It is a delicate, impermeable and avascular membrane covering the brain.
- It is lying between pia mater and dura mater.
- It separated from dura mater by a potential space, the subdural space
- It is separated from pia mater by the subarachnoid space
- The outer and inner surfaces covered with flattened mesothelial cells.
- It extends out over the cranial nerves and fuses with their epineurium.
- The cerebral arteries entering the substance of the brain, carry a sheath of pia mater with them.
- The pia mater forms the TELA CHOROIDAE.
- The tela choroidea fuse with ependyma to form the choroid plexus.
- Choroid plexus forms CFS.
What is the brain?
It is one of the largest Organ in the body and coordinates most body activities.
It is the centre for all -thought, memory, judgement and emotion.
Each part of the brain is responsible for controlling different body functions, such as temperature regulation and breathing.
Functions of brain
- The brain is contained in skull and weight 1300-1400g
- It is made up of about 1000 billion neurons 7 each neuron is surrounded by about 10 glial cells ( neuroglia).
- Neurons cannot multiply and many neurons are lost every day in life but glial cells can multiple throughout life.
- The brain is also covered by "Meninges" like a spinal cord -outer diameter, middle arachnoid matter and inner pia mater.