Lecture 2 Flashcards
What are the 3 membranes of connective tissue collectively known as?
meninges
What are the 3 layers of connective tissue that surround the CNS (from outside to inside)?
- dura mater
- arachnoid matter
- pia matter
Thick layer of dense connective tissue that attaches to the inner surface of the neurocranium in the skull
dura mater
What separates the the dura mater from the walls of the vertebral canal?
epidural space
What are the 3 layers of protection of the CNS?
- bone
- connective tissue
- fluid (CSF)
When is the epidural space present in the brain?
during signs of pathology (ex., direct skull trauma)
What are the two layers of dura that make up the dura mater?
- outer periosteal layer
- inner meningeal layer
What layer of dura is attached to the inner surface of the cranial cavities?
periosteal layer
What is the space called between the dura mater & arachnoid mater?
subdural space
When is subdural space present?
only during pathology
What is between the arachnoid mater & pia mater?
subarachnoid space
In which space do you find CSF?
subarachnoid space
At certain locations the meningeal layer separates itself from the periosteal layer and folds inwards creating what?
dural folds/reflections
What are the main things that drain the venous blood of brain to the circulatory system?
dural sinuses
Which fold divides the two hemispheres of cerebrum?
falx cerebri
What divides the cerebrum from the cerebellum?
tentorium cerebelli
What divides the 2 hemispheres of the cerebellum?
falx cerebelli
Pair of sinuses located in middle cranial fossa on either side of the hypophyseal fossa of the sphenoid bone & collect venous blood of orbital cavity contents (mouth, face, nose, eye)
Cavernous sinuses
Where are the inferior & superior sagittal sinuses located?
within superior & inferior margins of falx cerebri
What does the superior sagittal sinus receive cranial blood from?
superior aspects of brain
What does the inferior sagittal sinus receive blood from?
deep within & around diencephalon
What sinus receives blood from the inferior sagittal sinus?
straight sinus
Which sinuses receive blood from the superior sagittal & straight sinus?
confluence sinuse
Where are the transverse sinuses located?
posterior margin of tentorium cerebelli
What receives blood from the confluence sinus?
transverse sinuses
What receives blood from the transverse sinus?
sigmoid sinuses
Where are the sigmoid sinuses located?
groove on interior surface of mastoid process of temporal bones
What does the sigmoid sinuses drain into?
internal jugular vein
Smaller protrusions of arachnoid through dura mater
arachnoid villus/granulations
What does the arachnoid granulations allow for?
draining of CSF so it can enter venous circulation
When does subarachnoid space end?
vertebra S2
Which layer of meninge is adhered to neural tissue?
pia mater
Which layer of meninge of the brain carried blood vessels?
pia mater
What are the 2 differences between the meninges of the spinal cord and the meninges of the brain?
- epidural space is present
- dura mater only has one layer
What is the one layer of dura mater in the spinal cord?
meningeal layer
What is the dura sac made of?
dura & arachnoid mater
Where does the dural sac attach to?
- Foramen magnum
- C1-C2
- Level of S2
Enlargement of subarachnoid space b/w conus medullaris (~L2) & end of dural sac (~S2) due to end of spinal cord
Lumbar cistern
In which area of the spinal cord is the spinal tap (lumbar puncture) done?
lumbar cistern
Thickenings of pia mater suspending spinal cord in middle of its dural sheath
denticulate ligaments
Where are the denticulate ligaments positioned?
b/w each spinal nerve root
Extension of pia mater that anchors conus medullaris & dural sac to coccyx
Filum terminale
Conus medullaris
End of spinal cord
- L1/2 in adults
- L4 in children
Cauda equina
Remaining spinal nerves (continue after cord has ended)
What are 4 components of the ventricular system of the CNS?
- 2 lateral ventricles
- 3rd ventricle
- cerebral aqueduct
- 4th ventricle
How are the lateral ventricles connected to the 3rd ventricle?
interventricular foramen
What connects the 3rd ventricle to the 4th ventricle?
cerebral aqueduct
Where is the cerebral aqueduct located?
through midbrain b/w 3rd & 4th ventricle
T/F: 2 lateral ventricles are found in all 4 lobes of brain
true
Where is the 3rd ventricle located?
b/w thalamic nuclei (diencephalon)
Where is the 4th ventricle located?
b/w pons & cerebellum
What is the 4th ventricle connected to inferiorlt?
central canal
What are the foramen that connect the 4th ventricle to the subarachnoid space?
- 2 lateral apertures
- 1 median aperture
Specialized arterial plexuses located within the ventricular spaces & produce CSF from arterial blood
choroid plexuses
What are the 2 primary blood supply systems?
- carotid system
- vertebra-basilar system
What are the 3 branches of the carotid system (internal carotid artery)?
- middle cerebral artery
- anterior cerebral artery
- anterior communicating artery
Which arteries make up the circle of willis?
- anterior cerebral artery
- anterior communicating artery
- internal carotid artery
- posterior communicating artery
- posterior cerebral artery
What are the branches of the vertebra-basilar system?
- vertebral arteries
- basilar artery
- posterior cerebral artery
- posterior communicating arteries
- posterior anterior inferior cerebellar artery
- superior cerebellar
Which artery of the vertebra-basilar system would cause occipital lobe-cortical blindness if damaged?
posterior cerebral artery
Which artery of the vertebra-basilar system is most likely at risk for injury?
posterior anterior inferior cerebellar artery (PICA)
Which arteries of the vertebra-basilar system cover the brainstem?
- posterior anterior infereior cerebellar artery
- superior cerebellar
T/F: Single anterior spinal artery is able to supply/do more than the 2 posterior spinal arteries
True
The anterior and posterior spinal arteries receive supplemented blood from which arteries?
- intercostal artery (at thoracic level)
- lumbar artery (at lumbar level)
Which arteries supply 1/3 of the spinal cord?
posterior spinal arteries
Which artery supplies 2/3 of the spinal cord?
anterior spinal artery
