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293 Cards in this Set
- Front
- Back
What does the Nervous System originate from?
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Neuroectoderm
Neural Crest Mesoderm |
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What part of the NS originates from Neuroectoderm?
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CNS neurons
Ependymal cells (make CSF) Oligodendroglia Astrocytes |
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What parts of the NS originate from the Neural Crest?
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Schwann Cells
PNS neurons |
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What parts of the NS originate from mesoderm?
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Microglia
|
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What is Nissl?
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RER in neuron cell bodies and dendrites
|
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Fxns of Astrocytes?
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Physical Support
Repair K metabolism Removal of excess NT's Maintenance of BBB Reactive gliosis in response to injury |
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Marker for astrocytes?
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GFAP
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What are Microglia?
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CNS Phagocytes
|
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How do Microglia change in response to tissue damage?
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small irregular nuclei w/ relatively little cytoplasm
---> large ameboid phagocytic cells |
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What happens to microglia in HIV?
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HIV-infected microglia fuse to form multinucleated giant cells in the CNS
|
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Fxn of Oligodendrocytes?
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Each one myelinates multiple CNS axons (up to 30 each)
|
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Appearance of Oligodendrocytes?
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H&E: fried egg
Nissle stain: small nuclei, dark chromatin, little cytoplasm |
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What can destroy oligodendrocytes?
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Multiple Sclerosis
|
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Fxn of Schwann Cells?
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Each one myelinates 1 PNS axon
Promote axonal regeneration |
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What can destroy Schwann Cells?
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Guillain-Barre syndrome
|
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Neoplasm associated w/ Schwann cells?
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Acoustic Neuroma (schwannoma)
|
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Typical location of Acoustic Neuroma?
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Internal Auditory Meatus (CN VIII)
|
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Different Types of Sensory Corpuscles?
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Free Nerve Endings
Meissner's Corpuscles Pacinian Corpuscles Merkel's Disks |
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Types of Free Nerve Endings?
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C fibers
A-delta fibers |
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Where are they located and what do they sense:
Free Nerve Endings? |
All skin
Epidermis Some viscera Pain and Temperature |
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Where are they located and what do they sense:
Meissner's Corpuscles? |
Glabrous (hairles) Skin
Dynamic fine touch (e.g. manipulation) adapt quickly |
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Where are they located and what do they sense:
Pacinian Corpuscles? |
Deep skin layers
ligaments joints Vibration Pressure |
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What do Merkel's Disks look like?
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Cup-Shaped
Unencapsulated |
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Where are they located and what do they sense:
Merkel's Disks? |
Hair follicles
Static Touch (shapes, edges, textures) adapt slowly |
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Peripheral Nerve Layers (inside out)?
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Endoneurium
Perineurium Epineurium |
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What does Endoneurium surround?
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Single Nerve Fiber
|
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Fxn of Perineurium?
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Permeability Barrier
Surrounds fascicle of nerve fibers Must be rejoined in limb reattachment |
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Fxn of Epineurium?
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Dense CT surrounds entire nerve (fascicles and blood vessels)
|
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Types of NT's?
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NE
Dopamine 5-HT ACh |
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Changes in Disease for NE?
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Inc in Anxiety
Dec in Depression |
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Changes in Disease for Dopamine?
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Inc in schizophrenia (inc DA/ACh ratio)
Dec in Parkinson (dec DA/ACh ratio) |
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Changes in Disease for 5-HT?
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Dec in anxiety and depression
|
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Changes in Disease for ACh?
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Dec in Alzheimer's and Huntington's
|
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Location of Synthesis for NE?
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Locus Ceruleus
|
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Location of Synthesis for DA?
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Ventral Tegmentum
Substantia Nigra (pars compacta) |
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Location of Synthesis for 5-HT?
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Raphe nucleus
|
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Location of Synthesis for ACh?
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Basal Nucleus of Meynert
|
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What makes up the BBB?
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1. Tight Junctions between nonfenestrated capillary endothelial cells
2. BM 3. Astrocyte Processes |
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What is able to cross the BBB under normal conditions? how?
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Glucose and AA's cross slowly by carrier-mediated transport mechanisms
Nonpolar/Lipid soluble substances cross rapidly via diffusion |
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Exceptions to BBB?
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Few specialized areas w/ fenestrated caps and no BBB allow molecules in blood to affect brain fxn or neurosecretory products to enter circulation?
|
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2 Examples of areas where a lack of BBB allows molecules to affect brain fxn?
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Area Postrema: chemo--->vomiting
organum vasculosum of the lamina terminalis (OVLT) (aka supraoptic crest): osmotic sensing |
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Other blood barriers in body?
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Blood-Testis barrier
Maternal-Fetal blood barrier of placenta |
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effect of infarction on BBB?
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destroys endothelial tight junctions---> vasogenic edema
|
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Fxns of Hypothalamus? mnemonic?
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TAN HATS
Thirst and water balance Adenohypophysis control Neurohypophysis releases hormones Hunger Autonomic regulation Temp regulation Sexual urges |
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Inputs to Hypothalamus?
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OVLT
Area postrema |
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Where are the post. pit. hormones produced?
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Supraoptic Nucleus: ADH
Paraventricular nucleus: Oxytocin |
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What is the fxn of the Lateral area of the Hypothalamus?
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Hunger
so destruction---> anorexia |
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What ihibits the lateral hypothalamus?
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Leptin
|
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Fxn of Ventromedial Hypothalamus?
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Satiety
destruction--->hyperphagia |
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What stimulates Ventromedial Hypothalamus?
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Leptin
so leptin stops your hunger and increases your feeling of being full |
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Fxn of Anterior Hypothalamus?
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Cooling
Parasympathetic |
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Fxn of Posterior Hypothalamus?
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Heating
Sympathetic |
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Fxn of Septal Nucleus of Hypothalamus?
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Sexual urges
|
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Fxn of Suprachiasmatic Nucleus?
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Circadian Rhythm
|
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General Fxn of Thalamus?
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Major relay for asc. sensory info that ultimately reaches cortex
|
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Important Nuclei of the Thalamus?
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Lateral Geniculate (LGN)
Medial Geniculate (MGN) Ventral Posterior nucleus, lateral part (VPL) Ventral Posterior n, medial part (VPM) Ventral Anterior and Lateral Nuclei (VA/VL) |
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Fxn's of LGN?
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Visual
|
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Fxn's of MGN?
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Auditory
|
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Fxn's of VPL?
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Body Sensation (proprioception, pressure, pain, touch, vibrations)
|
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Fxn's of VPM?
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Facial Sensation (via CN V)
|
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Fxns of VA/VL nuclei?
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Motor
|
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Blood supply to Thalamus?
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Posterior Communicating
Posterior Cerebral Anterior Choroidal Arteries |
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Structures of the Limbic System?
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Cingulate Gyrus
Hippocampus Fornix Mammillary Bodies |
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Functions of Limbic System? mnemonic?
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5 F's
Feeding Fleeing Fighting Feeling Sex |
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Where does the Cerebellum's input come from?
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Contralateral Cortical Input via Middle cerebellar Peduncle
Ipsilateral proprioceptive info via Inferior Cerebellar peduncle Input nerves = climbing and mossy fibers |
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What kind of output does the Cerebellum give out?
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Stimulatory feedback to contralateral CTX to modulate movement
Output nerves = Purkinje fibers output to deep nuclei of cerebellum, which in turn output to CTX via Superior Cerebellar Peduncle |
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Nuclei of Cerebellum?
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Deep Nuclei(L-->M) Dentate, Emboliform, Globuse, Fastigial
|
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What are the Fxns of the Lateral and Medial Vermi?
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Lateral: Voluntary movements of extremities
Medial: Balance, Truncal coordination |
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2 pathways of the Basal Ganglia?
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Excitatory (direct)
Inhibitory (indirect) |
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Fxn of DA on the 2 basal ganglia pathways?
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DA stimulates the excitatory path (inc motion)
DA inhibits the inhibitory pathway---> inc motion So in parkinson's, when you have dec DA, you get decreased motion x's 2 |
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Gross morphological changes associated w/ Parkinson's?
|
Lewy Bodies (of alpha-synuclein)
Depigmentation of substantia nigra pars compacta (loss of dopaminergic neurons) |
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Rare cause of Parkinson's?
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MPTP
contaminant of street drugs |
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What is Hemiballismus?
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sudden, wild flailing of 1 arm
|
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Cause of Hemiballismus?
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Lesion of contralateral subthalamic nuclei
Loss of inhibition of thalamus through globus pallidus. Normally, the inhibitory pathway tells me to not move my arm. Without that pathway (i.e. w/ a lesion of the STN) my arm can do what it wants |
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Inheritance and Genetics of Huntington's?
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Auto Dom trinucleotide repeat disorder.
Chromosome 4 CAG repeats |
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Gross Morphological Changes seen in Huntington's?
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Atrophy of Caudate Nucleus (loss of GABAergic neurons)--->enlarged ventricles on CT
|
|
Sx's of Huntington's?
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Chorea
Depression Progressive Dementia |
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What is chorea?
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sudden, jerky, purposeless movements
|
|
Typical etiology of chorea?
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Basal Ganglia lesions
|
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What is Athetosis?
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Slow, writhing movements
esp of fingers |
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Typical etiology of Athetosis?
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Basal Ganglia lesions TOO!
(seen in HD) |
|
3 Types of Tremors?
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Essential/Postural
Resting Intention |
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What is an essential tremor? etiology?
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Action Tremor
Auto Dom disorder |
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Rx for Essential Tremor?
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Alcohol (self-medication)
Beta-Blockers |
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When do you see resting tremors? most affected part of body?
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PD (pill-rolling tremor)
Most noticeable distally |
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What is an Intention tremor?
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slow, zigzag motion when pointing toward a target
|
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General etiology of Intention Tremor?
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Cerebellar dysfxn
|
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Where are Broca's and Wernicke's areas? fxns?
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Broca's is more anterior area and handles motor speech
Wernicke's is more posterior near root of temporal lobe and handles the Associative auditory cortex Both are located on Dominant Hemisphere |
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Frontal Lobe Fxns?
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Planning
Inhibition Concentration Orientation Language Abstraction Judgment Motor Regulation Mood |
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how is the homunculus arranged?
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medial to lateral
feet legs trunk arms hands face this is mostly the same for motor and sensory |
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Patient presents w/ ____, where is their lesion?
Motor aphasia w/ good comprehension (nonfluent/expressive) |
Broca's area
|
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Patient presents w/ ____, where is their lesion?
Sensory aphasia (fluent/receptive) w/ poor comprehension, neologisms |
Wernicke's
|
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Patient presents w/ ____, where is their lesion?
Conduction Aphasia; good comprehension, fluent speech, but poor repetition |
Arcuate fasciculus
|
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Patient presents w/ ____, where is their lesion?
Kluver-Bucy Syndrome: hyperorality, hypersexuality, disinhibited behavior |
Amygdala (bilateral)
|
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Patient presents w/ ____, where is their lesion?
Personality changes, deficits in concentration, orientation, and judgment May have reemergence of primitive reflexes? |
Frontal Lobe
|
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Patient presents w/ ____, where is their lesion?
Spatial Neglect Syndrome (agnosia of the contralateral side of the world) |
Right Parietal Lobe
|
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Patient presents w/ ____, where is their lesion?
Reduced level or arousal and wakefulness (e.g. coma)? |
Reticular Activating System (midbrain)
|
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Patient presents w/ ____, where is their lesion?
Wernicke-Korsakoff Syndrome (confusion, confabulation, ophthalmoplegia, ataxis) |
Mammillary Bodies (bilateral)
|
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Patient presents w/ ____, where is their lesion?
Tremor at rest, chorea, athetosis? |
Basal Ganglia
|
|
Patient presents w/ ____, where is their lesion?
Intention Tremor Limb ataxia Falls |
Cerebellar Hemisphere
damage to cerebellum results in ipsilateral deficits, so the pt will fall towards the side of the deficit |
|
Patient presents w/ ____, where is their lesion?
Truncal ataxia dysarthria |
Cerebellar vermis
|
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What is dysarthria?
|
motor inability to speak
|
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Patient presents w/ ____, where is their lesion?
Contralateral hemiballismus? |
Subthalamic Nuclei
|
|
Patient presents w/ ____, where is their lesion?
Anterograde amnesia (can't make new memories) |
Hippocampus
|
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Patient presents w/ ____, where is their lesion?
Eyes look away from side of lesion? |
Paramedian pontine reticular formation (PPRF)
|
|
Patient presents w/ ____, where is their lesion?
Eyes look towards lesion? |
Frontal Eye Fields
|
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What is aphasia?
|
higher-order inability to speak
|
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What are the 4 main types of Aphasia?
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broca's
wernicke's Global Conduction |
|
Compare Broca's and Wernicke's?
|
B: Nonfluent aphasia w/ intact comprehension
W: Fluent aphasia w/ impaired comprehension |
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What is global aphasia/
|
G: Nonfluent aphasia w/ impaired comprehension
i.e. both broca's and wernicke's areas affected |
|
What is conduction aphasia?
|
Poor repetition, but fluent speech w/ intact comprehension
damaged arcuate fasciculus which connects broca's and wernicke's areas |
|
areas of brain supplied by posterior, middle, and anterior cerebral arteries?
|
Anterior: Medial surface of brain, leg-foot area of motor/sensory ctx
Middle: Lateral brain, trunk-arm-face area of motor/sensory ctx, broca's, wernicke's, optic radiations, attention Posterior: Visual CTX |
|
What is the most common site of circle of willis aneurysms? sx?
|
Ant. Communicating artery
visual field deficits from impingement on optic chiasm |
|
Aneurysm of Post. Communicating artery--->?
|
CN III palsy
|
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Where do the Lateral Striate arteries come from? what do they supply?
|
Come from Middle cerebral
Supply Internal Capsule, caudate, putamen, globus pallidus |
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What does an infarct of the internal capsule--->?
|
Pure Motor Hemiparesis
|
|
What are the main watershed areas? significance?
|
between ant and mid cerebral a's
between mid and post cerebral a's Damaged by severe HTN---> upper leg/upper arm weakness and defects w/ higher-order visual processing |
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What is Wallenberg's Sydnrome? Sx? Cause?
|
Infarct of PICA
Sx: nystagmus, ipsilateral ataxia, N&V, horner's syndrome |
|
What causes locked-in syndrome?
|
Basilar Artery Infarct
|
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In general, what does a stroke of the anterior circle of willis--->?
|
General sensory and motor dysfxn
Aphasia |
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In general, what does a stoke of the posterior circle of willis--->?
|
CN deficits (Vertigo, visual deficits)
Coma Cerebellar deficits (ataxia) |
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Location of Berry Aneurysm?
|
Bifurcation of circle of willis
most common ant. communicating |
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Most common complication w/ a Berry Aneurysm?
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Rupture--->hemorrhagic stroke or subarachnoid hemorrhage
|
|
Disease associations w/ Berry Aneurysm?
|
Adult Polycystic Kidney Disease
Ehlers-Danlos Marfan's |
|
Other risk factors for Berry's?
|
Older age
HTN Smoking Race (inc w/ blacks) |
|
What are Charcot-Brouchard aneurysms?
|
Microaneurysms affecting small vessels
|
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What areas are usually affected by Charcot-Brouchard aneurysms?
|
Basal Ganglia
Thalamus |
|
disease association for Charcot-Brouchard aneurysms?
|
Chronic HTN
|
|
Most common cause Epidural Hematoma?
|
Ruputre of Middle meningeal artery secondary to fracture of temporal bone
|
|
Sx's of Epidural Hematoma?
|
lucid interval
|
|
CT of Epidural Hematoma?
|
Biconvex Disk not crossing suture lines
can cross falx and tentorium |
|
Causes of Subdural Hematoma?
|
Rupture of bridging veins
|
|
Sx's and onset of Subdural hematoma?
|
Venous bleeding is under less pressure--->delayed onset of Sx's
|
|
Risk factors for Subdural Hematomas?
|
Elderly
Alcoholics Blunt Trauma Shaken Baby |
|
CT of Subdural hematoma?
|
Crescent-shaped hemorrhage that crosses suture lines
can't cross falx and tentorium |
|
Cause of Subarachnoid hemorrhage?
|
Rupture of Aneurysm (usually berry) or an AVM
|
|
Sx's of Subarachnoid Hemorrhage?
|
Worst HA of life
Bloody or yellow CSF |
|
Delayed risk for subarachnoid hemmorhage? rx?
|
2-3 days later there is a risk of vasospasm
rx w/ CCB's |
|
What causes parenchymal hematoma?
|
HTN
Amyloid angiopathy DM Tumor |
|
Typical locations for parenchymal hematoma?
|
Basal Ganglia
Internal Capsule |
|
3 types of strokes?
|
Hemorrhagic
Ischemic Transient |
|
Causes of Hemorrhagic Stroke?
|
Intracerebral bleeding
aneurysm rupture Secondary to ischemic stroke following reperfusion (inc vessel fragility) |
|
Causes of Ischemic Strokes?
|
emboli block large vessels
A-fib Carotid Dissection patent Foramen Ovale Endocarditis |
|
What are small vessel ischemic infarcts called? causes?
|
Lacunar Strokes
secondary to HTN |
|
Rx for Ischemic strokes?
|
tPA w/in 3 hours
|
|
What is a TIA?
|
brief, reversible episode of neurologic dysfxn due to focal ischemia
Sx's last < 24 hrs |
|
Strokes on Imaging?
|
MRI: bright on diffusion-weighted MRI w/in 30 minutes
CT: Dark on CT in a day |
|
Starting from the tippy top of my head, how does blood get out of my head?
|
Superior Sagittal Sinus
Confluence of Sinuses Transverse Sinus Sigmoid Sinus Internal Jugular V |
|
Staring more interior of head, how does blood get out?
|
Inferior Sagittal Sinus and Great Vein of Galen come together to become Straight sinus
Straight sinus meets up w/ superior sagittal sinus at confluence |
|
Who drains the inferior, anterior brain?
|
cavernous sinus
|
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Who makes CSF?
|
Ependymal cells lining the ventricles
|
|
How is CSF reabsorbed?
|
Arachnoid granulations in venous sinuses (mostly in superior sagittal)
|
|
How does CSF get from Lateral ventricles to Spinal cord?
|
Lateral V's
Foramen of Monro 3rd V Cerebral Aqueduct 4th V To subarachnoid space via Foramina of Luschka (lateral) and Foramen of Magendie (medial) |
|
What is Hydrocephalus?
|
Accumulation of excess CSF in ventricular system---> inc ICP and ventricular dilation
|
|
how does hydrocephalus present?
|
inc ICP and ventricular dilation---> Triad: dementia (wachy), gait problems (wobbly), and urinary incontinence (wet)
|
|
3 types of Hydrocephalus?
|
Normal pressure (communicating)
Obstructive (noncommunicating) Hydrocephalus ex vacuo |
|
Cause of Normal pressure Hydrocephalus?
|
Impaired absorption of CSF by arachnoid granulations (e.g. arachnoid adhesions post-meningitis)
|
|
Cause of Obstructive Hydrocephalus?
|
Structural blockage of CSF circulation w/in ventricular system (e.g. stenosis of aqueduct)
|
|
Cause of Hydrocephalus ex vacuo?
|
appearance of inc CSF in atrophy
ICP normal, no Sx's |
|
How many spinal nerves are there? divisions?
|
31
8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccygeal |
|
how do spinal nerves exit the vertebral column?
|
C1-C7 exit above their corresponding vertebrae
The rest exit below |
|
Most common site of vertebral herniation?
|
between L5 and S1
|
|
In adults where does the SC end? how bout subarachnoid space? importance?
|
SC at level of L1-L2
subarachnoid to lower border of S2 So do a puncture around L3-L4 or L4-L5 |
|
What are the 7 structures you have to pierce to get a spinal tap?
|
Skin
Ligaments (supraspinous, interspinous, ligamentum flavum) Epidural space Duramater Subdural space Arachnoid Subarachnoid space (csf!!) |
|
3 Main tracts of SC?
|
Dorsal Columns
Lateral Corticospinal Tract Spinothalamic Tract |
|
What does the Spinothalamic tract transmit? organization?
|
From medial to lateral, it goes cervial to sacral (legs are lateral)
Transmits pain and temperature |
|
What do the Lateral Corticospinal tracts transmit? organization/
|
Voluntary Motor
Legs are Lateral arms are medial |
|
What do the Dorsal Columns transmit?
|
Pressure
Vibration Touch Proprioception |
|
How are the Dorsal Columns divided up? significance?
|
Fasciculus Cuneatus (lateral)
Fasciculus Gracilis (medial) Cuneatus: upper body, extremities Gracilis: lower body, extremities so not legs are not lateral |
|
Where are the Sympathetics transmitted in the SC?
|
Intermediate horns (only in thoracic cord)
|
|
Which tracts are ascending? descending?
|
Dorsal columns and Spinothalamic are ascending
Corticospinal is descending |
|
Take the Dorsal column from the 1st order neuron all the way up?
|
Sensory Nerve Endings---> cell body in DRG---> enters SC and ascends ipsilaterally in dorsal column
Synapses at ipsilateral nucleus cuneatus or gracilis in Medulla Crosses over in medulla and ascends contralaterally in medial lemniscus Synapses at VPL of thalamus Relayed to Sensory CTX |
|
Take the Spinothalamic tract from the 1st order neuron all the way to the top?
|
Sensory Nerve Endings (a-delta and C)---> cell body in DRG---> SC
Ascends ipsilaterally in gray matter Crosses at Anterior White Commissure and ascends contralaterally Synapses at VPL and is relayed to Sensory CTX |
|
Take the Lateral Corticospinal tract from the top down?
|
UMN's cell body in Primary Motor CTX--->descends ipsilaterally through internal capsule and crosses at caudal medulla (pyramidal decussations--->desc contralaterally
Synpases at cell body in anterior horn of SC (LMN) Leaves SC--->NMJ |
|
What does a UMN lesion do to:
Weakness Atrophy Fasciculations Reflexes Tone Babinski Spastic Paralysis |
UMN
Inc weakness no atrophy no fasciculation Inc reflexes inc Tone Positive babinski Does exhibit spastic paralysis |
|
What does a LMN lesion do to:
Weakness Atrophy Fasciculations Reflexes Tone Babinski Spastic Paralysis |
Inc weakness
Inc atrophy Inc Fasciculations dec reflexes dec tone negative babinski No spastic paralysis |
|
Which tracts are ascending? descending?
|
Dorsal columns and Spinothalamic are ascending
Corticospinal is descending |
|
How do you get Poliomyelitis?
|
Poliovirus via F-O route
|
|
Course of Poliomyelitis?
|
Virus replicates in oropharynx and SI before heading via the blood to the CNS where it destroys cells in anterior horn of SC--->LMN destruction
|
|
Take the Dorsal column from the 1st order neuron all the way up?
|
Sensory Nerve Endings---> cell body in DRG---> enters SC and ascends ipsilaterally in dorsal column
Synapses at ipsilateral nucleus cuneatus or gracilis in Medulla Crosses over in medulla and ascends contralaterally in medial lemniscus Synapses at VPL of thalamus Relayed to Sensory CTX |
|
Sx's of Poliomyelitis?
|
LMN sx's:
weakness and atrophy fasciculations fibrillation hyporeflexia Malaise HA fever Nausea Abd pain sore throat |
|
Take the Spinothalamic tract from the 1st order neuron all the way to the top?
|
Sensory Nerve Endings (a-delta and C)---> cell body in DRG---> SC
Ascends ipsilaterally in gray matter Crosses at Anterior White Commissure and ascends contralaterally Synapses at VPL and is relayed to Sensory CTX |
|
Clinical findings w/ Poliomyelitis?
|
CSF w/ lymphocytic pleocytosis and slight elevation of protein (no change in glucose)
Virus recovered from stool or throat (hopefully not stool in throat) |
|
Take the Lateral Corticospinal tract from the top down?
|
UMN's cell body in Primary Motor CTX--->descends ipsilaterally through internal capsule and crosses at caudal medulla (pyramidal decussations--->desc contralaterally
Synpases at cell body in anterior horn of SC (LMN) Leaves SC--->NMJ |
|
What does a UMN lesion do to:
Weakness Atrophy Fasciculations Reflexes Tone Babinski Spastic Paralysis |
UMN
Inc weakness no atrophy no fasciculation Inc reflexes inc Tone Positive babinski Does exhibit spastic paralysis |
|
What does a LMN lesion do to:
Weakness Atrophy Fasciculations Reflexes Tone Babinski Spastic Paralysis |
Inc weakness
Inc atrophy Inc Fasciculations dec reflexes dec tone negative babinski No spastic paralysis |
|
How do you get Poliomyelitis?
|
Poliovirus via F-O route
|
|
Course of Poliomyelitis?
|
Virus replicates in oropharynx and SI before heading via the blood to the CNS where it destroys cells in anterior horn of SC--->LMN destruction
|
|
Sx's of Poliomyelitis?
|
LMN sx's:
weakness and atrophy fasciculations fibrillation hyporeflexia Malaise HA fever Nausea Abd pain sore throat |
|
Clinical findings w/ Poliomyelitis?
|
CSF w/ lymphocytic pleocytosis and slight elevation of protein (no change in glucose)
Virus recovered from stool or throat (hopefully not stool in throat) |
|
What is Werdnig-Hoffman disease? inheritance?
|
Infantile Spinal Muscular Atrophy
Auto Rec disorder associated w/ degeneration of ant. horns w/ LMN involvement only |
|
Sx's of Werdnig-Hoffman?
|
Floppy Baby
Tongue Fasciculations |
|
Life expectancy w/ Werdnig-Hoffman?
|
Median age of death = 7 months
|
|
What is ALS?
|
Amyotrophic Lateral Sclerosis (lou gehrig's)
|
|
Sx's of ALS?
|
UMN and LMN signs!!!
No Sensory, Cognitive, or Oculomotor deficits |
|
Possible etiology of ALS?
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Defect in Superoxide Dismutase 1 (SOD1)
Betel Nut Ingestion |
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What is Tabes Dorsalis?
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Degeneration of the Dorsal Columns and Dorsal roots due to Tertiary Syphilis
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Sx's of Tabes Dorsalis?
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Impaired Proprioception
Locomotor Ataxia Charcot's joints Shooting (lightning pain) Argyll Robertson pupils Absent DTR's |
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What are Charcot's Joints
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Chronic, progressive degeneration of one or more joints
swellin, instability, heat, hemorrhage, etc |
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What are Argyll Robertson pupils?
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Prostitute pupils!
accomodate, but don't react (to light) |
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What is Friedreich's Ataxia? genetics?
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Auto Rec Trinucleotide repeat disorder (GAA)---> impaired mitochondrial functioning
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Sx's of Friedreich's Ataxia?
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Staggering Gait
Frequent Falling Nystagmus Dysarthria Hypertrophic cardiomyopathy |
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How does Friedrich's Ataxia present?
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in childhood w/ kyphoscoliosis
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What is Brown-Sequard Syndrome?
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Hemisection of SC
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Sx's and Findings for Brown-Sequard?
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1. Ipsilateral UMN lesion sx's below lesion (corticospinal)
2. Ipsilateral loss of tactile, vibration, proprioception below lesion (dorsal column) 3. Contralateral pain and temp loss below lesion (spinothalamic) 4. Ipsilateral loss of all sensation at level of lesion 5. LMN signs (e.g. paralysis) at level of lesion |
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What if the Brown-Sequard lesion is above T1?
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You also get Horner's Syndrome
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What is Horner's Syndrome?
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Sympathectomy of the Face
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Sx's of Horner's?
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Ptosis
Anhidrosis (absent sweating) and flushing Miosis (pupil constriction) |
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What is Horner's usually associated w/?
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Lesion of SC above T1
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Landmarks for Pudendal nerve block? lumbar puncture?
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PNB: ischial spine
LP: Iliac crest |
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Landmark Dermatomes:
C2 C3 C4 |
C2 posterior half of skull
C3 high turtleneck C4 low collar shirt |
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Landmark Dermatomes:
T4 T7 T10 |
T4: nipple
T7: xiphoid process T10: umbilicus |
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Landmark Dermatomes:
L1 L4 wiener |
L1: inguinal ligament
L4: knee caps S2, 3, 4 keep the wiener off the floor (erection and sensation of penile and anal zones) |
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How does Muscle Spindle work?
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Spindle in parallel w/ muscle fibers
Muscle stretch--->intrafusal stretch---> stimulates Ia afferent---> corresponding alpha motor neuron--->reflex extrafusal contraction |
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What is up w/ the Gamma Loop of spindle?
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CNS stimulates gamma motor neuron--->contracts intrafusal fiber---> inc sensitivity of reflex arc
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Clinical Reflexes and who they're testing?
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Biceps: C5, 6
Triceps: C7, 8 Patella: L3, 4 Achilles: S1, 2 Babinski: sign of UMN lesion after 1 year of age |
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5 Primitive Reflexes?
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Moro: extension of limbs w/ scare
Rooting: nipple seeking Sucking: roof of mouth Palmar and Plantar: curling of fingers/toes if palm stroked Babinski: fan up |
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Which CN's lie medially at BS?
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3, 6, 12
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Location and Fxn of Pineal Gland
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Dorsal view of BS. Superior and medial
Secretes melatonin and thus controls circadian rhythms |
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What lies below Pineal Gland in same view?
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Superior and Inferior Colliculi (in pairs)
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Fxns of Colliculi? Pathology?
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Superior: Conjugate vertical gaze center. Lesion here--->paralysis of conjugate vertical gaze = Parinaud Syndrome
Inferior: auditory |
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What does CN III control?
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SR, IR, MR, IO muscles
Pupillary Constriction Accomodation Eyelid Opening (levator palpebrae) |
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Who are CN V, VII, IX, XII?
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V: Trigeminal
VII: facial IX: Glossopharyngeal XII: Hypoglossal |
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Fxn of CN V?
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Trigeminal
Muscles of Mastication Facial Sensation |
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Fxns of CN VII?
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Facial Movements
Taste for ant 2/3 of tongue lacrimation Salivation (submand, subling) Eyelid closing (orbicularis orculi) Stapedius muscle (ear) |
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Fxns of CN IX?
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Taste for post. 1/3 tongue
Swallowing Salivation (parotid) Monitors Carotid body and sinus Stylopharyngeus (elevates pharynx, larynx) |
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Fxns for CN X?
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Taste from epiglottic region
Swallowing Palate elevation Talking Coughing Thoracoabdominal viscera Monitor Aortic arch chemo and baro-receptors |
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Fxns of CN-XII?
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Tongue movements
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Where are the nuclei for the CN's located?
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Tegmentum of BS
Midbrain: III, IV Pons: V, VI, VII, VIII Medulla: IX, X, XI, XII |
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How does nuclei location affect fxn?
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Lateral: sensory
Medial: motor |
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CN Reflexes? aff? eff?
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Corneal: aff-V1, eff-VII
Lacrimation: aff-V1, eff-VII Jaw Jerk: aff-V3 (sensory), eff-V3 (motor) Pupillary: aff-II, eff-III Gag: aff-IX, eff-IX, X |
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Vagal Nuclei?
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Nucleus Solitarius
Nucleus Ambigus Dorsal Motor Nucleus |
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Fxn of Nucleus Solitarius?
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Visceral Sensory Info (taste, baroreceptors, gut distention)
VII, IX, X |
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Fxn of Nucleus Ambigus?
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Motor innervation of pharynx, larynx, and upper esophagus (swallowing, palate elevation)
IX, X, XI |
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Fxn of Dorsal Motor Nuclei?
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Sens autonomic (Para) fibers to heart, lungs, and upper GI
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How do CN I-->VI exit the skull?
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CN I: cribiform plate
CN II-->VI go through Middle Cranial Fossa through the sphenoid bone CN II: Optic canal (w/ ophthalmic artery and retinal vein) CN III: Sup. Orbital Fissure CN IV: SOF CN V1: SOF CN V2: Foramen Rotundum CN V3: Foramen Ovale CN VI: SOF |
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Who else exits via middle crania fossa in the sphenoid bone? where exactly?
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Middle Meningeal Artery via Foramen Spinosum
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How do the rest of the CN's get out of the head?
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Posterior Cranial Fossa through the temporal or occipital bone
CN VII: Internal Auditory Meatus CN VIII: IAM CN IX, X, XI: Jugular foramen CN XII: Hypoglossal canal |
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What goes through foramen magnum?
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Spinal roots of CN XI
BS Vertebral arteries |
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Where is the Cavernous Sinus?
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On both sides of pituitary
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What does the Cavernous sinus drain?
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Eye
Superficial CTX |
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What passes through the Cavernous Sinus?
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CN III
CN IV CN V1 &2 CN VI so EOM nerves and V1&2 |
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What is Cavernous Sinus Syndrome? cause?
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due to mass effect
Ophthalmoplegia Ophthalmic and maxillary sensory loss |
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My tongue deviates to the right side?
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CN XII lesion on the RIGHT
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Jaw deviates to the right?
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CN V motor lesion on RIGHT side
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My uvula deviates to the right?
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CN X lesion on the LEFT side
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Its hard for me to turn my head to the left and my right shoulder is drooped?
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CN XI lesion on RIGHT
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motor innervation kicker for face?
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Upper face receives BILATERAL UMN innervation
Lower face receives Contralateral UMN innervation |
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So a Right side UMN lesion will do what to face?
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Contralateral (left) paralysis of lower face only. upper face is fine
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So a LMN lesion of facial nerve--->
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Ipsilateral paralysis of upper and lower face
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general cause of Bell's Palsy?
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Complete destruction of Facial Nucleus or all of its efferent fibers
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Sx's of Bell's Palsy?
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Peripheral ipsilateral facial paralysis w/ inability to close eye on involved side
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Specific disease associations w/ Bell's Palsy?
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Idiopathically (gradual recovery usually)
AIDS Lyme disease Herpes zoster Sarcoidosis Tumors Diabetes |
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What are the KLM Sound tests? what do they test?
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Kuh Kuh Kuh tests palate elevation (CN X)
La La La tests tongue (CN XII) Mi Mi Mi tests lips (CN VII) |
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Who are the Muscles of Mastication? innervation?
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3 close jaw:
Masseter Temporalis Medial Pterygoid 1 opens jaw: Lateral Pterygoid Innervated by CN V3 |
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Generalizations for Muscles containing "glossus"? exception?
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All of them are innervated by CN XII
exception: palatoglossus by CN X |
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Generalizations for muscles containing "palat"?
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All of them are innervated by CN X
exception: tensor veli palatini who is innervated by CN V3 |
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Fluids of the inner ear? location, contents?
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Perilymph: in the bony labyrinth, Na rich, similar to ECF
Endolymph: in membranous labyrinth, K rich, Similar to ICF |
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2 main types of Hearing Loss?
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Conductive
Sensorineural |
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What happens with auditory test w/ a pt w/ Conductive hearing loss?
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Bone conduction > air conduction on Rinne
Weber localizes to affected ear |
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Auditory test results for a pt w/ sensorineural hearing loss?
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Air conduction > bone conduction on Rinne
Weber localizes to normal ear |
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What elements of the Inner Ear detect acceleration?
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Linear acc: Maculae detects it (located in utricle and saccule)
Angular Acc: Ampullae in the semicircular canals |
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What's the Cochlear membrane like? significance?
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A scuba flipper
Narrow and stiff at base (for high frequency sounds) Wide and Flexible at apex (for low frequency sounds) |
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What is the progression of hearing loss in elderly?
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High frequency---> low frequency
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Where are the anterior and posterior chambers of the eye?
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Ant: between cornea and iris
Post: behind iris, in front of lens |
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What is the Aqueous Humor Pathway?
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Produced by Ciliary Process
Does its thing Trabecular Meshwork absorbs humor Canal of Schlemm collects humor from meshwork |
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What is Glaucoma?
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Impaired flow of aqueous humor--->inc IOP--->optic disk atrophy w/ cupping
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Difference between Open and Closed Angle Glaucoma?
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Open: obstructed outflow (e.g. schlemm), painless, more common
Closed: obstruction of flow between iris and lens--->pressure buildup behind iris. Painful, dec vision |
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Risk factors for Open Angle Glaucoma?
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Myopia
Inc Age Black |
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Contraindicated meds for Closed Angle?
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Epinephrine
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What is a Cataract?
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Painless, bilateral opacification of lens---> dec vision
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Risk factors for Cataracts?
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age
smoking EtOH Sunlight Diabetes Trauma Infection |
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What is Papilledema?
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Inc ICP---> elevated optic disk w/ blurred margins, bigger blind spot
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If I damage CN III, what happens?
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Eye looks down and out
Ptosis Pupillary Dilation Loss of accomodation |
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If I damage CN IV what happens?
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Diplopia w/ downward gaze
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If I damage CN VI, what happens?
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Medially directed eye
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Fxns of the Superior Oblique muscle?
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Abducts
Intorts Depresses |
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What is Strabismus?
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misalignment of eyes
multiple etiologies |
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What is Amblyopia?
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Reduced vision from disuse/dysfxn of eye during a critical period of development (childhood)
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What can amblyopia be secondary to?
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strabismus
deprivation unequal refractive errors |
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What controls Miosis?
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Miosis = Constriction
Pupillary Sphincter Muscles innervated by the PANS via CN III via the Edinger-Westphal Nucleus---> ciliary ganglion |
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What controls mydriasis?
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myDriasis = Dilation
Radial Muscle (aka pupillary dilator) via SANS. Innervated by T1 preganglionic symapathetics--->superior cervical ganglion--->postganglionic sympathetic--->Long Ciliary Nerve |
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How does the Pupillary Light Reflex work?
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Light sends a signal via CN II to Pretectal nuclei in midbrain--->activates bilateral Edinger-Westphal nuclei---> pupils contract bilaterally (consensual reflex)
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What is a Marcus Gunn pupil?
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Afferent pupillary defect (e.g. optic nerve damage)---> dec bilateral pupillary constriction when light is shone in the AFFECTED eye
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In a cross section of CN III, what does what?
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Outside is for PANS output
Inside is for output to ocular muscles |
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how are the different areas of CN III cross-section affected differently?
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Outside is susceptible to compression via PCA berry, uncal herniation, etc---->screwed up pupillary light reflex
Inside is more susceptible to vascular disease (diabetes) |
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What is Retinal Detachment?
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separation of the neurosensory layer of retina from pigment epithelium---> degeneration of photoreceptors---> vision loss
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What can cause Retinal Detachment?
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Trauma
Diabetes |
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What is ARMD? types?
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Are-Related Macular Degeneration
Degeneration of Macula (centreal area of retina) Types: Dry and Wet |
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Sx's of ARMD? general and by type
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General:
Loss of central vision (Scotomas) Dry ARMD: slow, gradual loss of vision Wet ARMD: rapid vision loss due to neovascularization |
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What is MLF Syndrome?
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Internuclear Ophthalmoplegia
Lesion in medial longitudinal fasciculus |
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Sx's of MLF syndrome?
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Medial rectus palsy on attempted lateral gaze (i.e. look left. the left eye will go lateral and the right eye won't go medial.
Nystagmus in abducting eye Convergence is normal |
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Disease association for MLF syndrome?
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Seen with many MS pts
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