Lecture 9.1 Flashcards
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Roles of Glial cells of neurons:
1) Which can’t divide and are sensitive to acute injury?
2) Which are vulnerable to intracellular inclusions (Lewy bodies-Parkinson’s)?
1) Neurons
2) Neurons
Roles of Glial cells of neurons: what do the following do?
1) Astrocytes
2) Oligodendrocytes
3) Microglial Cells
1) Responsible for gliosis (repair and scar in the brain)
2) Produce Myelin
3) Function as the resident phagocytes of the CNS
Activated by infection, tissue injury, or trauma
Roles of Glial cells of neurons:
1) What do ependymal cells do?
2) What are ependymal cells prone to attack from?
3) What are they continuous with? What does this structure do?
1) Line the ventricles and central canal for the spinal cord
Ciliated and help to circulate CSF.
2) CMV
3) Choroid plexus; Secrete CSF
1) Define edema
2) Define vasogenic edema and give examples
3) Define cytotoxic edema and give examples
1) Accumulation of excess fluid within the brain parenchyma
2) Vasogenic edema - disruption of blood-brain barrier or cerebral capillaries
(trauma, tumors, inflammation, late stages of cerebral ischemia)
3) Cytotoxic edema – increased fluid secondary to damage of neuronal and glial cells
(hypoxic, ischemic, or various toxins)
Give examples of vascular CNS trauma (i.e. tearing of blood vessels)
1) Epidural: almost always trauma
2) Subdural
3) Intraparenchymal hematoma
4) Subarachnoid hemorrhage.
List examples of neural Tube Defects (folate deficiency)
1) Spina bifida- defects of the spinal cord or vertebrae
2) Myelomeningocele- extrusion of CNS tissue through defect in spinal column
3) Anencephaly- absence of the forebrain and top of skull
4) Encephalocele- diverticulum of malformed CNS extending through the cranium
1) What does the neural tube normally give rise to?
2) What happens if there’s partial failure of reversal or neural tube closure?
1) Neural tube gives rise to ventricular system, brain, and spinal cord
2) May lead to several abnormalities
Neural Tube Defects (folate deficiency):
1) Define spina bifida
2) Define Myelomeningocele
3) Define Anencephaly
4) Define Encephalocele
1) Defects of the spinal cord or vertebrae
2) Extrusion of CNS tissue through defect in spinal column
3) Absence of the forebrain and top of skull
4) Diverticulum of malformed CNS extending through the cranium
1) What is microencephaly? What is it often seen with?
2) What causes it?
1) Brain is too small; microcephaly
2) Chromosome abnormalities, fetal alcohol syndrome, HIV, and Zika (in utero)
List and describe the 2 main Posterior Fossa Anomalies
1) Arnold-Chiarri malformation-
Type I:
Type II:
2) Dandy Walker Malformation- enlarged posterior fossa, absence of cerebellar vermis, and large midline cyst
What are 4 routes for bacterial infections of the CNS?
1) Hematogenous route
2) Direct Implantation
3) Local extension
4) Peripheral nerves (often viral like rabies and herpes zoster)
CNS infections in epidural and subdural spaces:
1) What types of infections?
2) How do they usually happen?
3) What are the 2 types? What are the usual locations of each?
1) Involved in bacterial or fungal infections
2) Direct local spread
3) Abscess: usually epidural
Empyema: usually subdural
Meningitis
1) What is it called when it spreads to the brain?
2) What are the 2 groups of this subtype?
1) If infection spreads to the brain →meningoencephalitis
2) Acute pyogenic: bacterial
Aseptic: viral
Chronic: TB, spirochetal, or fungal
Inflammatory process within the leptomeninges is called what?
Meningitis
1) What causes prion diseases?
2) What is the pathogenesis?
3) What is an example of a prototypical prion disease?
1) Abnormal form of cellular protein
2) Prion protein → conformational change → protease resistant → then other molecules adopt this change → aggregation in neural tissue
3) Creutzfeldt-Jakob disease
Rapidly progressive dementing illness
Subtle changes to death in 7 months.
Tumors of the CNS may arise from the cells of:
“please do not memorize”
-the coverings (meningiomas)
-the brain (gliomas, neuronal tumors, choroid plexus tumors)
-other CNS cell populations (primary CNS lymphoma, germ cell tumors)
-Metastases
Tumors of CNS (do not memorize)
1) Distinct types of tumors affect specific brain regions; give 2 examples
2) What abt affecting specific populations?
1) cerebellum for medulloblastoma
intraventricular location for central neurocytoma
2) Pediatrics-medulloblastoma and pilocytic astrocytomas
Older patients- glioblastoma
List 3 types of glial tumors
1) Astrocytoma
2) Oligodendroglioma
3) Ependymoma
Medulloblastomas: Where are they located?
Exclusively in the cerebellum
Meningiomas:
1) Where are they found?
2) What may the Sx look like?
3) Are they invasive?
1) Along the external surfaces of the brain within the ventricular system
2) May be vague, non-localizing symptoms, or may be focal due to compression of adjacent brain
3) May be invasive or not
Carcinomas are the dominant type of systemic tumors that metastasize to the nervous system; give examples
2) Less than ___% of brain cancers represent metastases from other sites
1) Lung, breast, skin (melanoma), kidney, GI tract
2) 50%
Acute Eczematous Dermatitis:
1) Which kind appears as an abnormal reaction to UV or visible light?
2) Which type results from exposure to substances that chemically, physically, or mechanically damage the skin?
1) Photoeczematous dermatitis
2) Primary irritant dermatitis
Acute Inflammatory Dermatoses: Erythema multiforme
1) Erythema multiforme is characterized by what? What mediates this?
2) What is it related to?
3) What is it also assoc. with?
1) Epithelial injury mediated by skin-homing CD8+ cytotoxic T lymphocytes.
2) Related to hypersensitivity response to:
a) Infections: herpes simplex, mycoplasma, and some fungi
b) Drugs: sulfonamides, PCN, salicylates, hydantoins, anti-malarials
3) Some HLA haplotypes
Benign and Pre-Malignant Epithelial Lesions:
1) Which of has round, flat plaques made up of proliferating monotonous epidermal basal cells, which sometimes contain melanin? (hint: Hyperkeratosis and keratin-filled cysts are characteristic.)
2) Describe actinic keratosis
3) For the two conditions mentioned above, describe their malignancy
1) Seborrheic keratosis
2) Present on sun-exposed skin, these lesions show cytologic atypia in lower parts of the epidermis and infrequently progress to carcinoma in situ.
3) Although both are assoc. w. oncogenic mutations, malignant transformation is exceedingly rare in seborrheic keratoses and occurs in only a small subset of actinic keratoses.
Malignant Epidermal Tumors
1) Risk factors for cutaneous squamous cell carcinoma include what?
2) ___________ SCC has the potential for metastasis but usually is recognized and excised before it does so.
3) ________________, the most common malignancy worldwide, is a locally aggressive tumor associated with mutations in the Hedgehog pathway. Metastasis is very rare.
1) fair skin, UV light exposure, exposure to carcinogenic chemicals, chronic skin inflammation and scarring, and HPV infection (in the setting of immunosuppression).
2) Cutaneous
Melanocytic Proliferations:
1) Mostmelanocytic nevihave activating mutations inBRAFor less oftenNRAS,but the _____________ never undergoes malignant transformation and occur mostly in sun-exposed areas.
2) _____________ is a highly aggressive malignancy; tumors only a few millimeters in thickness can give rise to deadly metastases.
1) vast majority
2) Melanomais a highly aggressive malignancy
In most cases, melanoma progresses from an ________________ (in situ) to an ____________ (dermal) form.
intraepithelial; invasive
