Neuro Test 2 Flashcards
What are common clinical findings for lower motor neuron (anterior horn) paralysis?
Atonia, areflexia, fasciculation, and flaccid paralysis.
What tract contains upper motor neurons?
The corticospinal tract.
What are common clinical findings for a CST lesion?
Contralateral spastic hemiplegia, hyperreflexia, hypertonia, paralysis, and disuse atrophy
What resulted in supranuclear facial palsy?
Unilateral lesions of the uncrossed corticobulbar tract results in contralateral supranuclear facial palsy.
Where do corticobulbar fibers decussate?
In the lower pons and descend in the lower brainstem as crossed CBT.
What does a lesion in the crossed CBT result in?
Ipsilateral cranial nerve palsies.
What part of the internal capsule do corticobulbar fibers pass through?
Genu
Where does the corticospinal tract decussate?
In the medulla at the base of the pyramids
What is another name for a serotonin receptor?
5HT
What are the main serotonin receptors and the specific role for each of them?
5HT3 - Area postrema
5HT6 - Anti-depressant effect
5HT7 - Limbic system
What does a vesicular ACh transporter protein (VAChT) do?
Moves ACh into the vesicle
What does diamine oxidase do?
Catabolizes histamine
What does monoamine oxidase do?
Catabolizes epi, norepi, dopamine, and serotonin
What does acetylcholinesterase do?
Binds to the post-synaptic cell membrane and removes ACh from the synaptic trough
Where is norepinephrine found and what is its role?
Locus ceruleus and other pontine/medullary areas.
It is important in wakefullness/alertness
Where is epinephrine found and what is its role?
Medulla
Its role is modulatory
What is the amino acid is responsible for creating epinephrine?
Tyrosine
What are the stages forming epi from tyrosine?
Tyrosine –(Tyrosine hydroxylase(RLS), cytoplasm)–> L-DOPA –(cytoplasm)–> Dopamine –(Vesicle)–> norepinephrine –(PNMT, Outside of vesicle)–> epinephrine
What inhibits ACh transport into vesicles?
Reserpine
What helps transports norepi into the vesicle?
VMAT
Where is dopamine found and what role does it play in these specific locations?
Basal Ganglia - motor control
Hypothalamus and limbic system - Endocrine and emotional control
Cortex
What are the 5 receptor types for dopamine and what do they do?
D1 and D5 - Increase cAMP
D2 - decrease cAMP which leads to a potassium efflux
D3 and D4 - decrease cAMP
Where is serotonin (5HT) found and what role does it play in these specific locations?
Hypothalamus and limbic system - Mood
Cerebellum - Modification of motor activity
Brainstem Raphe nucleus - Modification of motor and sensory activity)
What amino acid is serotonin derived from?
Tryptophan
What enzyme turns tryptophan into serotonin?
Tryptophan hydroxylase
Where do you find histamine and what is its role in this location?
Tuberomammillary nucleus of the hypothalamus - Wakefulness
How is histamine made?
Histadine –(Histidine decarboxylase)–> Histamine
What are the different groups of histamine receptors and what do they do?
H1: PLC activation (involved in wakefulness)
H2: Increases cAMP (associated with gastric acid release)
H3: presynaptic, decrease histamine release
What are GABAs major roles?
Consciousness, motor control, and vision (retina)
How is GABA made?
Glutamate –(glutamate decarboxylase)–> GABA