Lecture 20: Brain & meninges Flashcards
How many bones is the cranium composed of?
8
What bones make up the cranium?
Frontal (1) Parietal (2) Temporal (2) Occipital (1) Sphenoid (1) - internal bone = ethmoid
What suture divides the frontal and parietal bones?
coronal suture
What suture divides the parietal and occipital bones?
lambdiodal suture
What suture divides the parietal and temporal bones?
squamous suture
How many bones is the facial skeleton composed of?
14
The facial skeleton has 7 external bones which are:
zygomatic (2)
mandible (1)
Maxillary (2)
Nasal (2)
What are the three meninges that protect the brain?
- Dura mater = tough mother
- Arachnoid = spider like - contains blood vessels
- Pia mother = delicate mother “lingerei for the brain”
The dura mater consists of two layers which are called?
- Outer layer = lines the skull
- Inner layer = inward extensions called dural reflections
which separate the major divisions of the brain
What does this dural reflection do?
- Falx cerebri
separates cerebral hemispheres
What does this dural reflection do?
- Falx cerebelli
separates cerebellar hemispheres
What does this dural reflection do?
- Tentorium cerebelli
separates the cerebrum from the cerebellum
What is the function of venous sinus?
- allow venous drainage from the brain
What is between the outer and inner layers of the dura mater?
- Venous sinus
= space btw the layers
What makes up the arachnoid layer?
- Arachnoid granulation/villi
- Subarachnoid space
What is the function of arachnoid granulations/villi?
- projects through dura mater into the venous sinus
- transports old CSF from subarachnoid space into venous sinus
- allows CSF to be recycled into the blood supply
What is the subarachnoid space?
- space btw arachnoid and pia mater which is filled with CSF
What does the pia mater do?
- adheres to the brain and follows gyri and sulci
What is the function of CSF?
-nourishes and protects the brain
Where is CSF produced?
produced by choroid plexus which line the ventricles
How does CSF get from ventricles into the blood?
Travels from ventricles into subarachnoid space then enters blood circulation within the venous sinus via arachnoid granulations
What route does CSF take?
- from ventricles to subarachnoid space
- lateral ventricle
- 3rd ventricle
- cerebral aqueduct
- 4th ventricle
- subarachnoid space to circulate around the brain & spinal cord
