TEST 1 review Flashcards
Position of 4th ventricle
Posterior to Pons
anterior to cerebellum
Choroid Plexus
1) Produce CSF
2) Located
- inferior and body of lateral ventricle
- 3rd
- 4th ventricles
CSF
1) Comes from blood (Plasma)
2) Average adult~150 cc of CSF at one time
- Produce 500cc CSF/day
- turned over 3-4 times daily
Trigone Area
1) If calcified=Glomus
- calcified choroid plexus
2) 25% of 20+ y.o will have some degree of calcification
3) appears radio-opaque on x-ray
Median Aperature
1) Foramen of Magendie
2) Not bilateral
3) empties into cisternal magna
- located at base of occipital bone
Lateral Aperature
1) Foramen of lushka
2) Bilatreral
3) empties into pontine cistern
Supratentorial Fossa
1) Area above tentorium cerebelli
Infratentorial Fossa
area below tentorium cerebelli
Leptomeningitis
1) pia mater + arachniod membrane inflamed
2) Bacterial mostly likely to cause
Diaphragma Sellae
surrounds pituitary gland
Diploic Vein
1) Provides venous drainage between the skull into sinus system
Emissary Vein
1) blood between scalp and sinuses-> venous system
Scalp Laceration
1) Serious Threat
2) Infection being spread into cranial vault through emissary veins
3) Results in Sepsis
Subgaleal Hematoma
1) b/w connective tissue and skull
2) trauma and newborns
3) emissary vein
4) Slow forming
3) heals on own most of time
Bridging Vein
1) supplies blood from venous sinuses
2) Causes:
- Increase in age causes decrease in elasticity of bridging veins
- dehydration
3) Subdural Hematoma
- b/w dura and arachnoid
Epidural Hematoma
AKA extradural hematoma
1) Location
- b/w skull and dura
2) Cause:
- trauma
3) Meningeal A. rupture
4) Fast forming
5) Very urgent due to Increase ICP
Subdural Hematoma
1) Location
- b/w dura and arachnoid membrane
2) Cause:
- trauma in elderly (fall)
3) Cerebral vein/ Bridging vein
4) Slow forming
5) Clincal urgency depends
Subarachnoid Hematoma
1) Location
- b/w arachnoid and pia
2) Trauma or ruptured aneurysm
3) Cerebral A.
4) Fast forming
5) EMERGENCY
Middle Meningeal Artery
1) Branches of maxillary artery
2) Foramen Spinosum
3) splits and anterior and posterior
- anterior goes through pterion
4) Buried in dura mater
5) Suppliees the Calvaria (dura and bone)
What is the most common non trauma subarachnoid hemorrhage?
1) Saccular Aneursym
- Middle cerebral artery
Aneurysms
1) Saccular
- occurs at Jxn of blood vessel
- very likely to rupture
2) Fusiform
- unlikley to rupture
3) Rupture can lead to stroke
- Middle Cerebral A.
True Aneurysm vs Pseudoaneurysm
1) True-comprises all 3 layers
- Tunica Intima (inner most)
- Tunica Media (middle)
- Tunica Adventia (outer)
2) Pseudo-doesn’t involve all 3 layers
- separation between tunica Media and Tunica Adventitia
- can be painful but don’t rupture
- due to trauma
Thalamostriate Vein
1) Lateral Ventricle
2) Drains the contents of lateral ventricle into interventricular foramen
3) Splits to form septal vein and internal cerebral vein
Septal Vein
1) Connected to thalamostriate vein
2) not in lateral ventricle
What are the 4 arteries that supply the brain
1) L and R vertebral Arteries
2) L and R internal carotid arteries
Anterior Cranial Fossa contains:
1) CN 1
2) Part of CN2
Middle Cranial Fossa contains:
1) Part of CN2, 5, 6
2) CN 3 and 4
3) Midbrain
Diencephalon
temporal lobe
cavernous sinus
internal carotide artery
middle cerebral artery
Posterior Cranial Fossa
Part of CN 5, 6
ALL of CN 7-12
Lamina Terminalis
1) Rostral wall of 3rd ventricle
- space between thalami
Septum pellucidum
1) Forms the medial wall of the anterior horn of lateral ventricles
Cavernous Sinus Syndrome
1) Aneursym or space occupying lesion in cavernous sinus
2) ipsilateral paralysis of eye movement (3,4, 6)
ipsilateral sensory issues across forehead, nose and cheeks
CINE MRI
1) Measures CSF not blood
2) traditional MRI w/wristband or EKG to measure heart rate
3) each time heart beats, CSF forced out of brain->spine
4) Shows CSF as it moves
Glasgow Coma Scale
1) Measures motor response(6), verbal response(5), and eye opening (4)
2) add all 3 up
- max score =15
- higher number higher functionality
CT
Computated Tomography
1) x-ray imaging-tissue density
-higher atomic number-greater ability to stop x-rays
2) Hounsfield units (CT numbers)
-attenuation intensities
3) Lesion or deficit in CT= hyperdense=White
-ex: acute subarachnoid hemorrhage
Hypodense=black
Isodense- same shade b/w region and brain
Advantages and disadvantages of CT
Advantages 1) quickly done -important in trauma 2) clearly shows acute and subacture hemorrhages into meningeal spaces and brain 3) Children in trauma cases 4)Show bone- Skull fractures 5( Less expensive than MRI
Disadvantages
1) doesn’t show:
- acute or subacute infarcts
- ischemia
- brain edema
2) doesn’t differentiate white matter from gray matter within brain clearly (VS MRI)
3) Exposed to Ionzing Radiation
MRI
Magnetic Resonance Imagine
1) Body tissue has proportionately high amounts of protons
2)Protons-function as tiny magnets
+ nucleus
- negative electron shell
-forms N and S poles
3) Radiofrequency pulse of radio waves into patient (protons)
-frequency of RP= spinning protons-> proton absorb energy from radio wave
-some protons canceled out
-magnetic effects and energy increases in some
4) 2 types of MRI-relate to effect of RP on protons
-MR1/T1-canceled out protons return to original magnetic strength
-MR2/T2-protons at higher levels loser energy more rapid
MRI: T1 vs T2
- hyperintense
- hypointense
- isointense
Hyperintense
- T1- shift more towards fat (more white)
- T2-shift more toward CSF (white)
Hypodense:
-T1/T2=darker than air or bone
Isotense:
T1/T2-same
Advantage/disadvantage of MRI
Advantage:
1) visualize a wide variety of abnormalities within brain
2) shows more detail of the brain
Disadvantages:
1) Does not show acute or subacute subarachnoid hemorrhage in the substance of the brain
2) Longer to due
- not useful in acute or trauma situations
- more expensive
- scan is loud and may require sedation in children
Ischmia
1) to keep blood (occluded arteries) from blood tissue
What courses through the internal acoustic meatus?
Labyrinthine Artery CN 7 (facial nerve-muscles of facial expression) CN8 (vestibulocochlear-sense of balance)
Lesion against internal acoustic meatus?
1) balance issues
2) paralysis of face
What courses through jugular foramen?
Internal Jugular Vein
CN9-glossopharyngeal
CN10-vagus
CN11-accessory
What three structures course through foramen magnum?
1) Vertebral Artery
2) Spinal Cord
3) Accessory Nerve
Respiratory Center in Brainstem
1) Pons/medulla
2) sends axons down spinal cord and synapse on phonic nerves
3) pacemaking of respiratory rate
Tonsilar Herniation
1) Space occupying lesion in PCF=Increased ICP
- Tonsil of cerebellum herniates through foramen magnum
2) Can disconnect communication b/w respiration center and the neurons of phrenic nerve
- patient can’t breath=DEATH
3) High cervical trauma
Mirror Neurons
1) facilitates teaching of movements
- watching others
- more efficient in learning motor movements
