Meninges and Ventricular system

• The Cranial meninges protect delicate brain tissues
• Label layers

  A) cranium

  B) dura mater

  C) arachnoid

  D) pia mater

  
• Label layers 2

  A) meninges

  B) brain

  C) dura mater

  D) arachnoid

  E) pia mater

  
• The dura mater consists of outer and inner fibrous layers.
• The outer layer of dura mater is fused to the periosteum of the cranial bones, which results to no epidural space.
• The inner layer of dura mater is fused together. When separated, they contain tissue fluids and blood vessels. They also form dura folds.
• The space between the outer and inner layer of the dura mater form venous sinuses.
• Dura folds are formed in the inner layer and separate major divisions of the brain. They support and stabilise the brain,.
• There are 3 types of dura folds:

  • falx cerebri
  • falx crebelli
  • tentorium cerebelli
• Falx cerebri is between the cerebral hemispheres. Its interior portions attach anteriorly to the crista galli and is along the midsagittal line (medial plane).
• Falx cerebelli separates the 2 cerebellar hemispheres along the midsagittal line.
• Tentorium cerebelli separates cerebral hemispheres from cerebellum.
• Label location of dura folds

  A) cerebrum

  B) cerebellum

  C) falx cerebri

  D) tentorium cerebelli

  E) falx cerebelli

  
• Label sagittal view dura folds

  A) falx cerebri

  B) falx cerebelli

  C) tentorium cerebelli

  
• The venous sinuses are large collecting veins located in the dura folds.
• Venus sinuses are located where 2 layers of dura mater separate
• In the venus sinuses contains old CSF after it's cycled through the ventricular system.
• The Arachnoid mater is a weblike substance that covers the brain, providing a smooth surface that doesn't follow underlying folds.
• The arachnoid mater is beneath the dura mater, above pia mater. it does not extend into the sulci and contains blood vessels within the subarachnoid space.
• The subarachnoid layer is between arachnoid and pia mater and filled with cerebrospinal fluid as it acts as a shock absorber.
• The subarachnoid layer is a network of collagen elastic fibres.
• The arachnoid granulations is the inner layer of dura layer and transport old CSF from subarachnoid space into venous sinus.
• Label subarachnoid and dura

  A) dura mater

  B) venous sinus

  C) outer

  D) subarachnoid space

  
• The pia mater is located in the inner layer of the meninges and are transparent and delicate. It sticks to the surface of the brain.
• Blood vessels in the arachnoid sit on top of the pia mater and follows gyri and extends into the sulci.
• Gyri are folds in the cerebral hemisphere that increase the surface area.
• Sulci are shallow grooves in the cerebral hemisphere that separate adjacent gyri.
• The ventricular system is a network of interconnected spaces within the brain.
• The ventricular system are filled with cerebrospinal fluid, which nourishes and protects the brain. the spaces are lined with ependymal cells, which articulate the CSF.
• CSF are produced by choroid plexus
• Label ventricular system

  A) lateral ventricle

  B) 2

  C) two

  D) one

  E) cerebral hemisphere

  F) third ventricle

  G) 1

  H) diencephalon

  I) cerebral aqueduct

  J) 1

  K) 3rd

  L) 4th

  M) midbrain

  N) fourth ventricle

  O) 1

  P) cerebellum

  Q) central canal

  
• The cerebrospinal fluid is produced by choroid plexus within the ventricles. It surrounds the CNS space within the subarachnoid space.
• The cerebrospinal fluid provides support and cushion and transports nutrients and waste.
• The circulation path starts at the 3rd ventricle to the 4th ventricle and flows around the brain and spinal cord and exits through the arachnoid granulations into the venous sinus.