Lecture 21

Question 1

What are menings

Answer 1

Protective covering for the brain

Question 2

What are the 3 layers of the mening for the brain

Answer 2

Dura matter
Arachnoid
Pia matter

Question 3

What is dura matter and the 5 features

Answer 3

Tough matter.
The 5 features:
- outermost layer of meninges
- dense and fibrous - tough
- two layers, inner and outer
- space between the layers form venous sinuses
- inner layer forms the dural folds

Question 4

Special features of Dura matter: dural folds, coronal view

Answer 4

• formed from inner layer of dura matter
• seperate major divisions of brain
• provide stability of the brain within cranium

Question 5

Special features of Dura Matter, dural folds

Answer 5

• Falx cerebri
  Seperates cerebral hemisphere
  Median plane
  Flax means sickle shaped
  • Falx cerebelli
    Seperates cerebellar hemispheres
    Median plane
  • tentorium cerebelli
    Seperates the cerebrum from the cerebellum

Question 6

Special features of Dura Matter, venous sinus: three features

Answer 6

• located where the 2 layers of dura matter seperate
• collecting veins
• they collect 2 things
  1) venous blood from the brain
  2) old CSF after it has cycled through the ventricular system

Question 7

What is the Arachnoid ( spider like layer )

Answer 7

This is the layer beneath the dura matter
Named because of the spider like appearance

Question 8

What are the 5 features of the Arachnoid

Answer 8

• layer beneath the dura matter
• layer above the Pia meter
• it does not extend into sulci ( valleys )
• contains 2 special features
  1) subarachnoid space
  2) arachnoid granulations
• contains blood vessels ( within the subarachnoid space, lying on top of the Pia meter )

Question 9

Special features of the arachnoid, subarachnoid space

Answer 9

Between the arachnoid and the Pia mater
Filled with cerebrospinal space ( CSF )

Question 10

Special features of Arachoid. Arachnoid granulations

Answer 10

• perforate the inner layer of dura mater
• transport ( old ) CSF from subarachnoid space into venous sinus

Question 11

What is Pia mater and the 4 features

Answer 11

Delicate mother
- inner layer of menings
- transparent and delicate
- blood vessels in arachnoid sits on top of Pia mater
- adheres to brain and follows gyri and extends into sulci

Question 12

The ventricular system and its 4 features

Answer 12

• network of interconnected spaces ( ventricles ) within the brain
• filled with cerebrospinal fluid ( CSF ) which nourishes and protects the brain
• spaces lined with ependymal cells, which circulate the CSF ( waving cilia )
• CSF is produced by the CHOROID PLEXUS

Question 13

The ventricular system ( anterior view )

Answer 13

Lateral ventricles ( 2 )
- there are 2 of them, one in each cerebral hemisphere

Third ventricle (1)
- located in the diencephalon

Cerebral aqueduct (1)
- connects third ventricle to the forth ventricle
- located in the midbrain

Forth ventricle
- located at the level of the cerebellum

Central canal ( spinal cord )

Question 14

The ventricular system ( lateral view )

Answer 14

It’s the same as the anterior view

• lateral ventricles ( 2 )
  Two of them, one in each cerebral hemisphere
• third ventricle (1)
  Located in the diencephalon
• cerebral aqueduct
  Connects third and forth ventricle
  Located in the midbrain
• Forth ventricle (1)
  Located at the level of the cerebellum

Central canal ( spinal cord )

Question 15

Cerebrospinal fluid (CSF) and its circulation. What are the 4 features

Answer 15

• produced by choroid plexus withen the venticales
• Surrounds the CNS, within subarachnoid space
• Provides support and cushion
• Transports nutrients and waste

Question 16

What is the circulation path of cerebrospinal fluid (CSF ) and its circulation

Answer 16

• Start: Lateral ventricles
  -> 3rd ventricle
  → cerebral aqueduct
  → 4th ventricle
  → subarachnoid space
  • Within subarachnoid space it flows around brain and spinal cord
  > Exit: through arachnoid granulations into the venous sinus