Cranium, Meninges, & Cerebral Blood Flow

Meninges & Spaces

100

Of the meninges, which layer has a direct blood supply? 

Dura Mater

200

What are considered the leptomeninges? 

Arachnoid Mater & pia mater

300

Which space is filled with CSF between the arachnoid and pia mater?

Subarachnoid space

400

The epidural space of the spinal meninges is the real space between the dura and vertebral periosteum. What does the cranial space consist of?

Potential space between the periosteum and calvaria 

500

What helps keep the brain suspended within the meninges? 

Arachnoid trabeculae

BBB

100

What is the purpose of the BBB?

Controls the movement of substances from ECF of the body to the ECF of the brain. 

200

What are the 3 regions that make up the BBB?

Arachnoid barrier, Blood-CSF barrier, & "True" BBB

300

What kind of medications can cross the BBB?

Nonionized, Lipid Soluble (Propofol) 

400

What cerebral structures lack the BBB?

3rd and 4th ventricles 

500

What is an example of a medication that will not cross the BBB?

Paralytics

CSF

100

List the order of CSF flow. 

Lateral ventricles (choroid plexus), Foramen of Monroe, 3rd Ventricle, Aqueduct of Sylvius, 4th Ventricle (Medial - foramen of Magendie & lateral - foramen of Luschka), Subarachnoid space, reabsorption per sinuses 

200

What is the estimated amount of CSF that is produced in a day? 

500 mL/day 

300

Where is CSF mainly absorbed? 

Superior sagittal sinus (via the arachnoid villi)

400

Communicating hydrocephalus is an issue with reabsorption and occurs distal to the exit from the 4th ventricle. What are two known causes of communicating hydrocephalus? 

Subarachnoid hemorrhage & Meningitis 

500

What is the estimated amount of CSF that is surrounding the CNS? 

150 mL

Arteries & Veins

100

This system of arteries supply about 20% of the brain's blood. What cerebral structures does it provide blood to? 

Brainstem, Cerebellum, and Spinal Cord

200

What are the branches of the internal carotid arteries? (Also, identify which one is prone to arteriosclerosis). 

Opthalmic**, Middle Cerebral Arteries, Anterior Cerebral Arteries, Anterior choroidal arteries, and posterior communicating arteries

300

The deep veins of the brain drain the internal cerebral structures. Where do these veins empty into?

Straight sinus

400

Superficial veins lie on the surface of the brain. Where do they mostly empty into?

Superior sagittal sinus

500

Which artery has a high risk of giving a patient "amaurosis fagax"? 

Opthalmic Artery (Temporary vision loss of one or both eyes due to sclerosis)

CBF

100

CBF averages about ______ ml/100 g/min

55 mL

200

When the brain receives less than 10 mL/100 g/min, what happens to the brain?

Irreversible brain damage

300

CBF is constant when the MAP is between 60-160 mmHg. If the MAP is > 160 mmHg there might be a chance of what? 

Cerebral hemorrhage or edema 

400

What has the most extrinsic influence on CBF?

PaCO2

500

What occurs when PaCO2 < 20 mmHg? 

Shifts O2/Hgb dissociation curve to the left, may result in EEG changes, & cerebral impairment