Green Study Guide Qs Flashcards
What channels are the first to affect the action potential?
Na+
What causes Na+ channels to become activated with little increases in membrane potential?
Calcium deficit
What does calcium deficit lead to?
Very excitable nerve
Where do local anesthetics act?
Blocks Na+ channel
What is the most common neurotransmitter?
ACh
Where do action potentials begin?
Initial segment
Release of what molecule causes muscle contraction?
Ca++
How are smooth muscle action potentials generated?
By stretch
What is a motor unit?
A single alpha nerve fiber excites 3-several hundred muscle fibers
What produces the CSF?
choroid plexus
Most proprioceptive pathways consist of what type of fibers?
Large myelinated fibers with very fast transmission time
Where is gait controlled from?
Midbrain and brainstem
What does plegia mean?
No voluntary movement at all
How does cerebellar ataxia present?
Dysmetria, movements that are too long or too short, goose stepping
How does vestibular ataxia present?
Leaning and listing to one side, crossing over of feet when walking
How does proprioceptive ataxia present?
Scuffing, hypometria
What controls the level of alterness?
Ascending reticular activating system
How would a lesion in cerebrum affect posture?
Rigid extension in all limbs, altered mentation
Compared to Schiff-sherrington (front legs work, back legs affected)
What is CN I?
Olfactory
Hard to test