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184 Cards in this Set
- Front
- Back
What does the anterior circulation supply and what major vessels comprise it?
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Supplies majority of cerebral hemisphere
Internal carotid a. Middle cerebral a. Anterior cerebral a. |
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What does the posterior circulation supply and what major vessels comprise it?
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Supplies occipital lobes, brainstem, cerebellum, spinal cord
Vertebral aa. Basilar a. |
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What is the circle of Willis?
|
The circle of Willis provides collateral pathways of blood flow. It includes the anterior and posterior communicating arteries.
|
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List some variations in the anatomy of the brain's blood supply.
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1. Only 20% of the population has a balanced circle of Willis
2. Posterior communicating artery hypoplasia % ............see slide |
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Which portions of the internal carotid artery have significant branches?
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Cavernous- aa. to pituitary and tentorium
Cerebral/supraclinoid- aa. to eye and brain |
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What are the major branches of the cerebral ICA?
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1. Ophthalmic
2. Posterior communicating.......... |
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What is the only branch arising from the dorsal aspect of the ICA?
What does this artery supply? |
Ophthalmic
Retina |
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What artery connects the ICA to the posterior cerebral artery?
With which cranial nerve does it have an important relationship? |
Posterior communicating artery
CNIII |
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Which artery supplies the optic tract, optic radiations, medial globus pallidus, posterior limb of internal capsule, hippocampus, amygdala, and choroid plexus of temporal horn?
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Anterior choroidal artery
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Which artery supplies the orbital surface of the frontal lobe, medial cerebral hemisphere, and medial basal ganglia?
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Anterior cerebral artery
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Which artery supplies the lateral cerebral hemisphere, caudate, putamen, and internal capsule?
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Middle cerebral artery
|
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What are the two components of the straight sinus?
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1. Inferior sagittal sinus (runs in free margin of falx)
2. Vein of Galen |
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What are the general components of the pharyngeal arches?
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Cartilage, nerve, artery, muscle, mesenchyme
|
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What are the two divisions of the first pharyngeal arch?
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Maxillary and mandibular
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What does the first pharyngeal arch cartilage become?
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Mandible, maxilla, malleus, incus
|
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What does the second pharyngeal arch cartilage become?
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Supporting elements of the jaw, stapes
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What does the cartilage of the third through sixth pharyngeal arches become?
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Supporting elements for the neck and larynx
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What is the cranial nerve that goes with each pharyngeal arch?
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Frontonasal process: Ophthalmic branch of CN V
Arch 1 (mandibular): Mandibular branch of CN V Arch 1 (maxillary): Maxillary branch of CN V Arch 2: CN VII Arch 3: CN IX Arch 4: Superior laryngeal branch of CN X Arch 6: Recurrent laryngeal branch of CN X |
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How can the muscles of the face be traced back to their pharyngeal arch of origin?
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Trace its motor innervation
|
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What nerve innervates the stylopharyngeus?
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Glossopharyngeal (IX)
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What nerve innervates the intrinsic laryngeal muscle?
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Vagus (X)
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What three structures arise from neural crest mesenchyme? Mesodermal mesenchyme?
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1. CF mesenchyme
2. Dura mater of brain 3. Ganglia of cranial nerves 1. Posterior skull bones 2. Striated muscle 3. Endothelium |
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From which nerve does the philtrum get its sensory innervation?
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Ophthalmic branch of CN V
|
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Describe the formation of the palate.
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Part of the frontonasal process descends as the philtrum and contributes to the anterior incisors and a little bit of the palate. The maxillary process grows toward the center from each side and joins.
|
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From where do the anterior 2/3 of the tongue arise?
Posterior 1/3? |
First pharyngeal arch tongue buds
Third and fourth arches |
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What nerves innervate the tongue?
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Anterior 2/3: Trigeminal (general sensory), facial (taste)
Posterior 1/3: Glossopharyngeal, vagus Hypoglossal (motor) for all muscles except palatoglossus (vagus) glossopharyngeal, vagus |
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From which pharyngeal arch does the external ear develop?
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First and second arch tissue, which form six hillocks (bumps)
|
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Which pharyngeal arch developed defectively in the following case:
Defects of external ear Mandibular hypoplasia Cleft palate |
First pharyngeal arch (first arch syndrome)
|
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From where does the inner ear arise?
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Surface ectoderm between the second and third pharyngeal arches
|
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Which nerve innervates the inner ear?
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Vestibulocochlear
|
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From which pharyngeal arch do the ossicles arise?
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First and second arch cartilage
|
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What does the first pharyngeal pouch become? Juxtaposition of the first pouch and first cleft?
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Tympanic cavity/Eustachian tube
Ear drum |
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Which nerves innervate the ear drum?
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Trigeminal and glossopharyngeal
|
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From where is the thyroid derived? Describe the process.
What is a developmental irregularity of this process? |
Tongue
The thyroid diverticulum invaginates into the tongue, descends, buds off, and migrates into the neck. The foramen cecum is a landmark on the surface of the tongue from where the thyroid arose. A pyramidal lobe is present if the thyroid fails to completely separate from the tongue. |
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What structures arise from the pharyngeal pouches?
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2nd: Tonsils
3rd: Thymus 3rd and 4th: Parathyroid 4th: Ultima branchial body -> calcitonin-expressing thyroid cells |
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What is a mental disorder?
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Behavior or psychological syndrome or pattern associated with present distress or disability. It reflects a behavioral, psychological, or biological dysfunction.
|
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What are the diagnostic criteria for schizophrenia?
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1. Two or more of the following:
a. Delusions b. Hallucinations c. Disorganized speech d. Grossly disorganized or catatonic behavior e. Negative symptoms 2. Social/occupational dysfunction 3. Duration of at least 6 months 4. Other disorders and conditions excluded |
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What are the five diagnostic axes of the DSM IV?
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1. Clinical disorders
2. Personality disorders and mental retardation 3. General medical conditions 4. Psychosocial/environmental problems 5. Global axis of function (scale of 1-100 quantifying functional level) |
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Differentiate between the first and second axes of the DSM IV.
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The second axis only looks at personality disorders and mental retardation to ensure that they must be considered in diagnosis of a patient and not overlooked in favor of more apparent conditions.
|
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What are the five DSM definitions that are not diagnoses?
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1. Major depressive episode
2. Manic episode 3. Hypomanic episode 4. Panic attack 5. Agoraphobia |
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What are substance-induced disorders?
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Substance-induced disorders are axis 1 disorders that are caused by substance use.
|
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Are mental disorders with medical conditions always based on the patient's reaction to their medical condition?
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No, a mental disorder can be a direct physiological effect of a medical condition.
|
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How is physical dependence demonstrated?
Are the same things present in substance dependence? |
Tolerance and withdrawal
They may be present but are not required for diagnosis. |
|
When does neurulation occur?
Along which part of the neural tube is a defect most likely? Why? |
Week 3-4 of development
The caudal end is most likely to have a defect because it is the last part to close. |
|
When does diverticulation occur?
What is diverticulation? |
Week 5 of development
Diverticulation is the process by which the telencephalic vesicles arise as lateral evaginations of the prosencephalic cavity- formation of two brain hemispheres. |
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Where does cell proliferation in the brain occur?
When in a pregnancy does most of the proliferation occur? |
In the germinal matrix, adjacent to the ventricle, around the region of the caudate nucleus.
First two trimesters |
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Along which cell type do neuroblasts migrate from the germinal matrix to the cortex?
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Radial glia
|
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When does gyration of the brain occur?
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Week 24 of development to term
|
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When does myelination of the brain occur?
Which region of the brain is myelinated first? |
Week 20 of development to 18 months after birth
Brain stem |
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When does axonal, dendritic, and synaptic development occur?
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Throughout life
|
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What is dysraphism?
Which developmental tissue layer does not form over the spine? |
Dysraphism is a defect in neural tube closure.
Mesoderm (lack of bone formation) |
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Give three examples of dysraphism.
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Spina bifida occulta- missing bone, may not ever be noted, lipoma, sinus tract, hair patch may be present on skin
Meningocele- fluid-filled sac protruding often in lumbo-sacral region, no neural deficit at birth, must be surgically repaired Myelomeningocele- fluid-filled sac containing neural tissue, associated with bowel, bladder, and lower limb dysfunction |
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What happens when there is poor closure of the anterior neuropore?
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Anencephaly- the brain is exposed to the intrauterine environment and is damaged then replaced with granulation tissue
|
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What is an encephalocele?
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Lack of closure of the back of the head resulting in protrusion of the brain or a fluid-filled sac.
|
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What is holoprosencephaly?
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Holoprosencephaly is a lack of diverticulation, which means the brain does not divide into two hemispheres. It is also often associated with external midline defects. Cyclopia may occur.
|
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What defects might occur with neural migration in the brain?
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Heterotopias- gray matter within the white matter. May be silent, or may cause seizures and/or mental retardation.
Polymicrogyria- fusion of multiple gyri resulting in possible seizures and/or mental retardation Agyria/lissencephaly- failure of gyral formation, incompatible with life Enlarged and broadened gyri |
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Describe what happens in a child with hydrocephalus.
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Increased amounts of CSF, creating increased ICP enlarges the skull because cranial sutures haven't fused yet.
|
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How is hydrocephalus classified?
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Obstructive vs. non-obstructive- Is CSF flow obstructed or is too much CSF being produced?
Communicating vs. non-communicating- Does the ventricular space communicate with the subarachnoid space? |
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What is hydrocephalus ex vacuo?
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Hydrocephalus ex vacuo occurs with wasting of the brain tissue and ventricular size is increased as a result of a lack of brain tissue rather than an increase in pressure.
|
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What percent of babies with neural tube defects also develop hydrocephalus?
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80%
|
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What is Arnold-Chiari malformation?
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Arnold-Chiari malformation is a combination of neural tube defect with hydrocephalus. When the neural tube fails to close, hindbrain crowding may occur and obstruct CSF flow, resulting in hydrocephalus. In another scenario, the cerebral aqueduct fails to form.
|
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What is the definition of mental retardation?
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1. Significant sub-average general intelligence functioning (IQ<70)
2. Concurrent deficits in adaptive behavior 3. Onset in developmental period |
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How is mental retardation classified?
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Amount of support required
|
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What causes mental retardation?
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1. Chromosomal abnormalities
2. Metabolic 3. Infections 4. Prenatal drug exposure 5. Malnutrition 6. Prematurity 7. Small for gestational age 8. Germinal matrix hemorrhage 9. Severe infections of CNS 10. Lead or mercury poisoning 11. Asphyxia |
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Describe cerebral palsy.
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*Impaired control of movement
*Congenital or acquired *Appearing in first few years of life *Does not worsen over time *Due to faulty development of or damage to motor areas |
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What are the signs and symptoms of cerebral palsy?
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1. Difficulty with fine motor tasts
2. Difficulty maintaining balance or walking 3. Involuntary movements 4. May be associated with seizures or mental retardation 5. Delayed developmental milestones |
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Name six possible causes of cerebral palsy.
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1. Cerebral malformation
2. Cerebral ischemia/hypoxia 3. Cerebral hemorrhage 4. Head injury 5. Jaundice (ie: Rh incompatibility) 6. Infections (ie: Rubella) |
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List four populations of babies that are at increased risk for developing cerebral palsy.
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1. Extreme prematurity
2. Low birth weight 3. Mechanical ventilation for several weeks 4. Intracerebral hemorrhage |
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Name a location in the brain that does not have a blood brain barrier.
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Pituitary
|
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Through what structures must substances travel to get from the capillary lumen to the brain?
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Endothelial cell with catabolic enzymes, basement membrane, astrocyte
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When in fetal development do tight junctions in capillaries in the brain form?
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Four months
|
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What can be noted when the fetal blood brain barrier begins to function?
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A drop in [protein] in CSF
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Which form of bilirubin is able to cross the blood brain barrier?
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Unconjugated
|
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What is the brain uptake index?
Put heroin, nicotine, aspirin, alcohol, anti-cancer agents, morphine, vitamin C, and caffeine in order of greatest to least BUI. |
BUI is a measurement of the relative uptake of a molecule into the brain compared to deuterium uptake.
Nicotine, alcohol, caffeine, heroin, vitamin C, morphine, aspirin, anti-cancer agents |
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What is the partition coefficient?
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The partition coefficient measures partition of oil and saline solution to predict accumulation behind the BBB. This is predicted by a computer now.
|
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Name three substances that easily enter the CNS?
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Gases and volatile anesthetics readily diffuse in.
Lipid soluble substances, like insecticides and heroin, rapidly accumulate and get trapped in the CNS. Glucose is taken up by facilitated transport, driven by concentration. |
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What substance can be used to identify brain regions with rapid glucose uptake?
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Isotope-labeled 2-deoxyglucose
|
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Why is galactosemia dangerous?
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High levels of galactose can prevent transport of glucose into the brain.
|
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What substance can be used to reduce brain volume in an emergency situation?
Why does this work? |
Mannitol
It does not cross the BBB and so it can decrease brain size by osmosis. |
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Name 2 substances that can compromise the BBB?
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1. Bordatella pertussis toxin
2. Intracerebral bacterial endotoxins like LPS- metalloproteinases are activated |
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Name two populations which are at risk for BBB damage.
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1. Alzheimer's patients
2. Users of drugs that increase BP (speed and LSD) |
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What proteins might be useful in transporting molecules across the BBB?
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TfR1 and anti-TfR1 because when the antibody binds TfR1 it will be transported across the barrier, so something could be conjugated to the antibody.
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What neurotransmitter is used by somatosensory neurons? What receptor does it go to?
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ACh
Nicotinic receptor |
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What neurotransmitter is released by postganglionic parasympathetic neurons? What receptor does it go to?
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ACh
Muscarinic receptor |
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What neurotransmitter is released by preganglionic parasympathetic neurons? What receptor does it go to?
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ACh
Nicotinic receptor |
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What is the action of parasympathetics on the eye?
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Pupil constriction and lens curving, tearing
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What is the parasympathetic action on salivation?
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Increased salivation
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What is the effect of parasympathetics on the heart?
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Slows heart rate via SA and AV nodes (no action on ventricles), decrease strength of contractions
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What is the effect of parasympathetics on arterioles?
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Relaxation via NO release
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What is the parasympathetic effect on bronchi?
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Constriction
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What is the parasympathetic effect on the GI tract and urinary tract?
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Contraction of smooth muscle and relaxation of sphincters
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Release of what neurotransmitter by sympathetics causes sweating?
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ACh
|
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Which wins if they have an armwrestling match: sympathetic or parasympathetic?
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Parasympathetic, by blocking norepinephrine release
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If a drug is used to block acetylcholine binding to receptors in the eye, what reactions would you expect?
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Dilation of the pupil, flattening of the lens, and lack of tearing
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What is a parasympathomimetic?
What are three synonyms? |
A drug that mimics the action of ACh released from parasympathetic nerve endings.
Cholinergic agonist Muscarinic agonist Cholinomimetic |
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What parasympathomimetics are used systemically?
Topically on the eye? |
Systemically: bethanechol and methacholine
Topically: carbachol and pilocarpine |
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If bethanechol is administered, what will happen to tearing, urination, and heart rate?
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Tearing: increased tear flow
Urination: contraction of bladder and relaxation of sphincter muscles at the neck of the bladder Heart rate: decreased |
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What is the only parasympathomimetic that is metabolized by AChE?
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Methacholine
|
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Which parasympathomimetic has the longest half life?
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Bethanechol
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Which parasympathomimetic is good for slowing heart rate?
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Methacholine
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What parasympathomimetic is good for the GI tract and urinary tract?
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Bethanechol
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A patient presents to the ER with BP 240/160, HR 140. What parasympathomimetic would control these symptoms? What side effects might occur?
|
Methacholine
Side effects: diarrhea, incontinence, urinary frequency, salivation, tearing, sweating |
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What does a negative chronotropic drug do?
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It slows down the heart rate by acting on the SA node.
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What does a positive ionotropic drug do?
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It increases the strength of heart contractions.
|
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How do baroreceptors modulate blood pressure?
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When the receptors sense change in pressure in the aortic arch or carotid sinus, the firing rate of neurons going to the medullary cardiovascular centers increases/decreases. Signals go to the sympathetics and parasympathetics. Parasympathetics slow the heart rate, decreasing BP, or sympathetics increase the heart rate and increase BP.
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What are T1 and T2 weighting in radiology?
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T1: water is dark and fat is bright- white matter is bright and gray matter is dark
T2: water is bright and fat is dark- white matter darker than gray matter |
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What two things must be present for contrast to enhance neuroimaging?
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1. Blood supply
2. Breakdown in BBB |
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What is fMRI imaging based on?
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Blood oxygen utilization
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How do you decide to use CT or MRI?
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CT: acute situations, trauma, acute stroke
MRI: non-acute situations, trauma, stroke, everything else |
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Describe typical symptoms of stroke.
|
Sudden weakness or numbness
Sudden vision change (double vision, visual field cut) Sudden headache Sudden difficulty speaking or understanding Sudden dizziness |
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What is hemorrhagic stroke?
What percent of strokes are hemorrhagic? |
Rupture of a blood vessel leading to bleeding in and around the brain.
20% |
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Name the three major types of ischemic stroke.
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Atherosclerotic
Lacunar (small vessels) Cardioembolic (clot from heart lodges in brain) |
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What is the most potent risk factor for stroke?
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Age
|
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What are the four important factors when evaluating a stroke?
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Where- Neuroanatomic localization
Where- Vascular localization When- Profile of onset How- Vascular mechanism |
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If you had a stroke in the posterior cerebral artery, what major symptom would appear?
Middle cerebral artery |
Visual symptoms
Weakness |
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What are the two systems of collateral blood flow in the brain?
|
Circle of Willis
Leptomeningeal |
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How can profile of onset help distinguish between ischemic and hemorrhagic stroke?
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Ischemic stroke has maximal symptoms at onset, while a hemorrhagic stroke will build to maximal over the course of minutes to hours.
|
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Name seven stroke risk factors.
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1. Age
2. HTN 3. Diabetes 4. Dyslipidemia 5. Smoking 6. Heart attack 7. Atrial fibrillation |
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Name 5 mechanisms of stroke.
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1. Atherosclerosis
2. Cardioembolic 3. Small vessel disease 4. Dissection 5. Cryptogenic |
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Which ischemic area in an acute stroke has reversible damage- core or penumbra?
|
Penumbra
|
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How can ischemic stroke be treated?
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1. Supportive care- fluids
2. Consideration of thrombolysis in early presenting patients 3. Anticoagulation 4. Antiplatelet agents 5. HTN management |
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How is intracerebral hemorrhage treated?
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1. Lower blood pressure
2. Supportive care 3. Reverse coagulopathy 4. Manage ICP |
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How effective are clot removal devices, when used within 8 hours of onset?
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54%
|
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What is the number one modifiable risk factor for stroke?
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Hypertension
|
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What parts of the brain are more vulnerability to hypxic/ischemic damage?
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1. Cortical neurons (layers 3 and 5)
2. Globus pallidus and hippocampal neurons (Sommer's sector/CA1) 3. Cerebellar Purkinje cells Cells in watershed areas, where there is overlap b/w perfusion by arteries. |
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How can Sommer's sector of the hippocampus be found?
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The dentate granule cells form an arrow that points to it. (anterior hippocampus) It is roughly equivalent to CA1.
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What cell response would you expect to see in an infarcted area of the brain?
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Gliosis
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What is an early (4-12 hr) sign of ischemic necrosis in the brain?
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Neurons undergoing eosinophilic ischemic necrosis.
|
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What is a way to distinguish between global and local ischemia of the brain?
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With global ischemia, both sides of the brain should be affected.
|
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What does laminar necrosis look like grossly?
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Granular appearance of cortical ribbon, with discoloration near the white matter.
|
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What is the difference between the core/center and the penumbra in a stroke?
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In the center, there is such profound ischemia that the tissue dies immediately. The center is surrounded by a penumbra, which is an area that is stressed but not dead and can be saved by early intervention.
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What is the most common cause of focal cerebral infarct?
|
Cerebrovascular atherosclerosis
|
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What area is most commonly affected by focal strokes?
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The territory of the MCA
|
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What is hydrocephalus ex vacuo?
|
Hydrocephalus ex vacuo is an increase in ventricle size due to tissue loss rather than increased CSF pressure.
|
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What does infarcted brain look like microscopically?
|
Vacuolated neuropil, edema, prominent vessels, pallor, lymphocytes, macrophages
|
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Characterize embolic strokes vs. thrombotic strokes.
|
Embolic: immediate vessel occlusion, may occur in multiple locations, more frequently hemorrhagic, most commonly lodge in MCA
Thrombotic: slow formation, solitary site, less frequently hemorrhagic |
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What, besides embolus, might cause multiple stroke locations?
|
Vasculitis
|
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What is a lacunar infarct?
|
A lacunar infarct is by definition smaller than 1 cm and may be multiple and bilateral. They often occur in the basal ganglia and pons. They may occur focal motor disease and dimentia.
|
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How can you tell if a vessel is chronically leaky?
|
There will be hemosiderin buildup in the surrounding tissue.
|
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What is congophilic angiopathy?
|
Deposition of amyloid in the walls of cerebral blood vessels. Associated with Alzheimer's disease. Results in hemorrhage in the cerebral hemispheres.
|
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What should you be concerned about if someone with no history of headache complains of the worst headache of their life?
|
Berry aneurism
|
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What is the main goal when treating subarachnoid hemorrhage?
|
Control vasospasm that occurs as a result of blood irritating blood vessels and causes secondary infarction.
|
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If you take care of one aneurism that a person has, are they likely to be okay after that?
|
No, aneurisms are often multiple and rebleed after treatment.
|
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What are the common locations of cerebral aneurisms?
|
Arterial bifurcations, Circle of Willis- anterior to posterior communicating arteries, basilar artery
|
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What is an arteriovenous malformation?
|
A congenital malformation of the vasculature where arterioles proceed directly to venules, rather than going through a capillary bed. They are superficial and typically over the cerebral convexity. They sometimes are silent, but often result in hemorrhage, seizures and focal deficits in the patient's 20's. They look like huge tangles of vessels by angiography. Hemosiderin, abnormal brain parenchyma, and calcification are often seen in tissue sections.
|
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What is a cavernous hemangioma?
|
Back to back thin-walled vessels located deep within the brain. They are usually asymptomatic but may cause seizures.
|
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What is a Duret hemorrhage?
|
Duret hemorrhage occurs as a result of uncal herniation. It occurs in the midline brainstem.
|
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What are the major effects of using a cholinesterase inhibitor?
|
Tearing, defecating, drooling, decreased heart rate, urinating, erection
|
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What are the two major differences in effect of direct parasympathomimetics and cholinesterase inhibitors?
|
Cholinesterase inhibitors do not have any effect on blood pressure.
Cholinesterase inhibitors cause muscle twitches because blocking cholinesterase at neuromuscular junctions causes the increased ACh to bind to the nicotinic receptors. |
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Are cholinesterase, nAChR, and mAChR structurally the same everywhere?
|
Cholinesterase is, but the two receptors are not.
|
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What is mydriasis?
|
Large expansion of the pupil due to disease or drugs
|
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A patient with a parasympathetic denervated right eye is given a cholinesterase inhibitor. What would be the expected outcome?
|
The right eye, which already had a large pupil, would stay the same. The left pupil would contract.
|
|
What three cholinesterase inhibitors do not cross the BBB?
|
Pyridostigmine, neostigmine, and edrophonium (quarternary amines). Physostigmine, a tertiary amine, will.
|
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What are donepizil (Aricept), galantamine (Razadyne), and memantine (Namenda) used to treat?
|
Alzheimer's disease
|
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What will be the effect of cholinesterase inhibitors on a patient with a heart transplant?
|
Nothing because nerves do not grow into the transplanted heart.
|
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What five conditions are cholinesterase inhibitors most often used to treat?
|
1. Atonic gut
2. Urinary retention 3. Glaucoma 4. Myasthenia gravis 5. Alzheimer's disease |
|
What class of drugs are used to diagnose and treat myasthenia gravis? Which two are used specifically?
|
Cholinesterase inhibitors
Diagnosis: edrophonium Treatment: pyridostigmine |
|
What are organophosphates?
|
Organophosphates are irreversible cholinesterase inhibitors. Isofluorophate is used in chemical warfare as nerve gas. Parathion is used as an insecticide.
|
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Compare the effects of pyridostigmine with the effects of bethanechol on the pupil, muscle, and brain.
|
Pupil: both will cause miosis
Muscle: Pyridostigmine will cause fasciculations. No effect by bethanechol. Brain: Neither will cross the BBB. |
|
List the signs and symptoms of cholinesterase inhibitor poisoning.
|
Bronchoconstriction
Diarrhea Increased urination Increased sweating, salivation, tearing Bradycardia Miosis Poor distance vision Erection Fasciculations Nausea Seizures Coma |
|
What is isofluorophate used to treat?
|
Glaucoma
|
|
How do organophosphates modify cholinesterase inhibitor?
What drug is used to treat organophosphate poisoning? |
Organophosphates phosphorylate cholinesterase inhibitors to an inactive form. PAM removes that phosphate.
|
|
When cholinesterase inhibitors get into ganglia, does sympathetic or parasympathetic predominate?
|
Parasympathetic
|
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Which nicotinic receptors are not blocked by ganglionic blockers?
|
Those in the skeletal muscle because the binding sites are too far apart.
|
|
Where do ganglionic blockers block?
|
At the nicotinic receptor on the post synaptic cell.
|
|
When ganglionic blockers are used, which effect wins out?
|
Sympathetic, except in the case of sweating.
Both are blocked in the male GU tract. |
|
What is the cardiac output?
|
Volume of blood pumped from the heart in one minute. 5 L/min in the average adult
|
|
What is the Frank-Starling Law?
|
The Frank-Starling law states that the greater the end diastolic volume, the greater the stroke volume.
|
|
What is the mechanism by which ganglionic blockers cause orthostatic hypotension?
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Ganglionic blockers cause orthostatic hypotension by blocking the sympathetic signal for arteriole constriction to maintain blood pressure. When the patient stands, the blood pools in the feet and a smaller volume is returned to the heart, so end diastolic volume is decreased. Lower EDV leads to lower stroke volume, leading to decreased cardiac output and lower BP. There is also decreased sympathetic signal directly to the heart, leading to decreased contractility. The patient faints.
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What is the primary agonist for the nicotinic receptor?
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Nicotine
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What is the primary agonist for the nicotinic receptor?
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Nicotine
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What are the actions of nicotine on GI, salivation, blood pressure, and skeletal muscle?
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GI: diarrhea
Salivation: increase Blood pressure: increase Skeletal muscle: fasciculations |
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What parts of the motor unit are affected in neurogenic neuromuscular diseases?
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Anterior horn cell and peripheral nerve (motor or sensory)
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What parts of the motor unit are affected in neuromuscular junction neuromuscular disease?
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Neuromuscular junction (duh)
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What parts of the motor unit are affected in myopathic neuromuscular disease?
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Muscle
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What disorder affects eye muscles, followed by speech and swallowing muscles, followed by extremities?
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Myasthenia gravis
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What sort of problem causes a slowed conduction velocity?
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Demyelination
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What does a repetitive stimulation study evaluate?
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Change in response amplitude- there should be no change
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What cell is damaged in ALS?
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Anterior horn cell- upper and lower motor neuron
Corticospinal tract degeneration |
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What is the inheritance pattern of ALS?
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90% of cases are sporadic, but 10% are autosomal dominant
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What are the symptoms of ALS?
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Cramps and fasciculations
Painless, no sensory signs Muscle weakness and atrophy Progressive and multifocal UMN signs Bulbar and respiratory symptoms |
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What is a prominent theory regarding the cause of ALS?
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Defective glutamate metabolism
(also oxidative stress, cytoskeletal, autoimmune) |
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What are the presenting symptoms of Guillain Barre Syndrome?
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Weakness
Facial weakness- facial nerve involvement Minimal objective sensory findings Areflexia Preceding infection or vaccination Sparing of sphincter function Autonomic dysfunction |
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How is Guillain Barre Syndrome treated?
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Plasmapheresis, IVIG
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