The _____ leads from the cell body (neuron) and is covered with mylin sheath which faciliates the rate of transmission of an impulse.
________ receive impulses at the synapse and lead toward the cell body (neuron).
The midbrain is beneath the ____________.
The spinal cord extends from the medulla oblongota to _______ at the conus medullaris.
What is the cauda equina?
"Horses tail": where spinal nerves extend past the end of the spinal cord.
The falx cerebri (part of the dura) divides?
The falx ceribelli (part of the dura) divides?
Tentouium cerebelli (part of the dura) divides?
cerebrum from the cerebellum
Middle "cobwebby layer" of the meninges?
Subarachnoid space is between the _______ and ______ and contains _______.
arachnoid and pia mater
What meningeal layer is highly vascular?
CSF is secreated by the _________.
Ventricle pathways: lateral ventricles to _________ to third ventricle to ________ to fourth ventricle to the _______ and ________.
interventricular foramen (foramen of Monroe)
Cerebral aquaduct (aquaduct of Sylvius)
Median aperture (foraman of Magendie) and Lateral apertures (foramen of Luschka)
Blood supply to the brain: anteriorly? posteriorly?
Anteriorly: bilateral internal carotid arteries
Posteriorly: bilateral vertebral arteries
___________ communicates between the bilateral internal carotid arteries and the bilateral vertebral arteries.
Circle of Willis
Circle of Willis is at about the level of the _______ in the brain.
About ____% of the population have a complete circle of willis.
Venous blood from the brain is returned to the venous sinuses in the dura and ultimately drain into __________.
internal jugular veins.
The blood-brain barrier prevents passage of many substances into the brain. It is however, permeable to ____, ______, _____, ______ and general _______.
What is inflammation of the meninges (pia and arachnoid layers)?
Two types of meningitis?
Of bacterial and viral meningitis, which is more serious?
Severe headaches, stiff neck, high fever, intolerance to light, painful when moving eyes side to side are clinical signs of?
The bacterial meningitis vaccine treats ___ different strands and protects for about ___ to ___ years.
An infected meninge may swell and close off the aquaduct between 3rd & 4th ventricle (aquaduct of Sylvius) which may lead to?
How is meningitis diagnosed?
What is usually a viral infection of the brain tissue and meninges transmitted by herpes or "arborvirus"(arthropod borne)?
Much more serious than meningitis
Pyogenic organisms from the ear, throat, lungs, and sinuses may cause a ______ in the brain.
Brain abscesses are best visualized with?
Note: Posterior fossa tumor of cerebellum or 4th ventricle is more common in children and often a primary tumor.
Note: anterior cerebrum tumor is more common in adults and is usually a metasticis from another cancer.
Brain tumors are best visualized with?
Astrocytoma- benign, slow growing, infiltrative character and found in cerebrum, cerebellum, optic chiasm, pons.
Glioblastoma is a malignant converted grade 4 astrocytoma. Highly malignant and patients only live 6-12 months after diagnosis.
Most common form of adult primary brain tumor?
glioblastoma (patients only live 6-12 months after diagnosis, peel incidence 45-50yrs)
Medulloblastoma- posterior fossa most often in children (15-20% of all PED tumors) boys affect 2x more than girls, radiosensative.
Meningoma- benign tumor, often has calcifications, more common in females (30-50yrs) well encapsulated, and may compress teh brain. Well seen in CT and MR.
Acoustic Neuroma- slow growing benign tumor, arrises from cells in 8th cranial nerve. Originates in IAC and extends into the cerebellopontine cistern.
Slow growing benign tumor that arrises from the cells of the 8th cranial nerve?
Pituitary adenoma- usually a benign tumor of anterior lobe of pituitary gland. Macroadenoma is over ____mm in size, and is also a _______ tumor. Tumor can compress teh pituitary gland causing hypopituitarism.
non-functioning (pituitary functions normally)
What pathology may grow out and erode the sella turcica and compress the optic chiasm?
Microadenoma of the pituitary gland (size _____) is a _____ tumor and causes _________ due to production of pituitary hormones.
1-10mm in size
Pathology? Occurs primarily in males under 25yrs usually around it's calcifying time, and is midline of brain.
Linear skull fracture?
sharp lucent line that is often irregular, jagged and sometimes branches.
Diastatic skull fracture?
linear skull fracture that intersects a suture line and courses along it causing sutural separation.
Depressed skull fracture?
Often stellate (star shaped) with multiple fracture lines radiating outward from a central point
blood coming from the ear, often a clinical sign of a basilar skull fracture.
purple or black-and-blue area ................bruise
Epidural Hematomas (2% of all head injuries) are caused by acute _______ bleeding of the _____ _______ _____, most often over the __________ convexity.
medial meningeal artery
What type of hematoma appears as a biconvex (lens-shaped), peripheral, high density lesion?
Subdural hematomas (10-20% of all head injuries) are caused by _______ bleeding, most often caused by ruptured ______ between the dura mater and arachnoid.
An acute _______hematoma typically appears as a peripheral zone of increased density and has a crescentic shape.
What is an injury to the brain tissue that is caused by movement of the brain within the calvaria after blunt trauma to the skull?
What type of hemorrhage can produce bleeding into the ventricular system?
The ___________ artery is associated in 50% of traumatic fistulas.
The most common facial fracture is?
nasal bone fractures
What is caused by a direct blow to the front of the orbit that causes a rapid increase in intraorbital pressure?
What method is the preferred screening study for a blowout fracture?
modified waters plain radiograph
What is a tripod fracture?
fractures of the zygomatic arch and the orbital floor or rim combined with separation of the zygomaticofrontal suture
Most common site of fracture of the mandible?
Le Fort fracture?
severe injury that involves bilateral and horizontal fractures of the maxillae (classified as I,II,III) resulting in a detached and unstable fragment.
Metastatic carcinoma of the brain most commonly arise from ______ (34%), and _________ (14%).
Most sensative modality for detecting suspected tumors of the CNS?
What is a cobalt 60 gamma ray?
Gamma knife (201 beams converge in one spot)
Why isn't contrast given to patients suspected of a brain injury?
Because blood looks like contrast in CT
What is a "battle sign?"
ecchymosis over the mastoid processes
What are "raccoon eyes?"
bilateral orbital ecchymosis
If there are fluid levels visualized in sphenoid sinus and mastoid air cells, CSF and/or blood leaking out of ears, it may indicate?
a basilar fracture
What type of projection is required to view the depth of a depression fracture?
What modality ages blood really well?
What is caused by a shearing force to intraparenchymal arteries at the junction of gray and white matter?
Most common cause of subarachnoid hemorrhage?
reptured berry aneurysm: causes CVA, bleeds into ventricles
Most common type of cerebral vascular accident CVA?
Ischemic CVA (thrombus/embolus)
The onset of an embolus is often _____ not related to ______.
What is an AVM?
aretiovenus malformation- tangled web of arteries and veins
What is hemiplegia?
paralysis on one side of the body, usually dealing with strokes
What is hemiparesis?
weakness on one side of the body, usually dealing with strokes
What is dysarthria?
difficulty speaking, usually dealing with strokes
What is the purpose of radiographic evaluation in the acute stroke patient?
Not to confirm the diagnosis, but rather to exclude other processes that can stimulate the clinical finding.
Cerebral hemorrhage vs subarachnoid hemorrhage. Which has a poorer prognosis?
Symptoms: rapid hemiplegia, loss of consciousness, headache, stiff neck?
1 in 3 experiencing a TIA will have a CVA within ____ years.
Degeneration of nerve tissue which causes mylin sheath in white matter of brain to degenerate. What is it?
MS- multiple sclerosis
May have a clinical sign of sudden blurred vision
Modality of choice for MS?
What type of seizure is mild where someone just kind of "spaces out?"
What type of seizure is considered major with a loss of consciousness?