Cerebral Blood Flow, Ventricles, meninges and CSF Flashcards
What is the magnum foramen?
Big hole, located at the bottom of the skull.
Space where spinal cord passes thru.
Important location where motor/sensory pathways crossover (decussate- important for speech production).
What are the 3 layers of the meninges?
- Dura Mater- outermost, tough
- Arachnoid- middle, weblike
- Pia Mater- innermost, tender
Define sulcus and gyrus:
Sulcus= valley
Gyrus= bump
Function of the meninges:
Provides buffering/coating to lobes, Provides stability, Anchoring
What is the innervation of Dura Mater?
Trigeminal nerve (CN 5)
What are 2 important branches in CN5?
- Opthalmic
- Mandibular
**See slide 18 in PPt.
Dura Mater blood supply?
Meningeal arteries- supplies bone marrow, spreads over inner surface of temporal & parietal bones
Describe outer and inner layers of arachnoid:
Outer layer- composed smooth tightly fitting cells impermeable to CSF
Inner layer- Arachnoid trabeculae – delicate strains of connective tissue that loosely connect arachnoid to pia mater
What is subdural space?
potential space that could exist between meningeal layer of dura mater and arachnoid layer
What is the subarachnoid space composed of?
filled with CSF, blood vessels and cisterns
What are arachnoid granulations?
pockets of arachnoid membrane, extend through dura mater into dural venous sinuses
Function: allows CSF to absorb into the bloodstream
What is the function of CSF?
Provides mechanical protection/cushioning “bubble wrap”
Facilitates homeostasis (removes waste)
Facilitates communication between CNS & Peripheral nervous system & Immune system
Where is CSF found?
ventricular system, cerebral, spinal, & arachnoid, spaces and perivascular spaces in CNS
What is the primary source of CSF?
choroid plexus
What are the 2 types of CSF flow?
- Connective flow (unidirectional)
- Pulsatile Flow (bidirectional)
What is hydrocephalus?
Excess CSF builds up in ventricles; enlarging one or more
How many cerebral ventricles are there?
4
How many lateral ventricles and what shape are they?
2, they are c-shaped
What are the 3 big components of the aorta?
- Brachiocephalic trunk/artery (may be labeled innominate)
- Left Common Carotid artery
- Left Subclavian Artery
What is the circle of willis?
Meeting of bilateral internal carotids, basilar (formed by merging of vertebral arteries), Posterior communicating artery.
Anterior Cerebral artery supplies what?
- Medial Frontal
- Medial
- Superior Parietal
Middle cerebral artery supplies what?
Majority of lateral surface of frontal, temporal, parietal
Posterior Cerebral artery supplies what?
the occipital lobe,
the inferomedial surface of the temporal lobe,
midbrain,
thalamus and
choroid plexus of the third and lateral ventricles.
Which artery supplies the midbrain?
Posterior Cerebral Artery (PCA)
Which 2 arteries supply the pons?
Basilar, AICA
Which artery supplies the medulla?
posterior & anterior spinal, Basilar
Which 3 arteries supply the cerebellum?
- PICA,
- AICA,
- SCA
Which 2 arteries supply the spinal cord?
posterior and anterior spinal
Define ischemia
inadequate blood perfusion to the tissue, associated with the area of the brain served by the compromised vessel
Define hypoxia
inadequate oxygenation
Define anoxia
no oxygen
Define infarct
A stroke…brain tissue that has died as result of ischemia and thus decreased oxygen to the tissue
What are the 3 types of aneurysm?
- Saccular/berry - pouching of one side of artery
- Fusiform – ballooning of all sides artery
- Mycotic – infection weakens the artery
What are the Central arteries
Anterior Choroidal
Ophthalmic
Anteromedial
Medial striate artery
Medial and lateral lenticulostriate
Posterior choroidal
Posteromedial
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