S2_L4: The Neuromuscular Junction, Neurotransmitters, and Neuromodulators Flashcards
What is the neurotransmitter of alpha motor neurons?
Acetylcholine
What do you call the depressions where the axon terminal imbeds?
Motor-end plate
What is peculiar with the NMJ?
It has junctional folds
TRUE OR FALSE: The NMJ has active zones and dense bars
True
TRUE OR FALSE: A propagated potential is always produced at the NMJ
True
TRUE OR FALSE: Even at rest, small quanta of ACh is released at the NMJ of skeletal muscle
True
TRUE OR FALSE: The NMJ of smooth and cardiac muscles have
recognizable end plates
False
TRUE OR FALSE: The axon terminal in the NMJ of smooth muscles contain many neurotransmitters.
True
TRUE OR FALSE: It is possible to produce inhibitory end-plate potentials at the NMJ of skeletal muscles
False
TRUE OR FALSE: The synapse en passant can produce inhibitory potentials in smooth muscles
True
TRUE OR FALSE: The more receptors, the more selective the neurotransmitters are
True
TRUE OR FALSE: There are receptors found in the presynaptic cell
True
TRUE OR FALSE: Nicotinic cholinergic receptors are cation channels
True
TRUE OR FALSE: Reuptake mechanisms serve to terminate
neurotransmission
True
TRUE OR FALSE: Metabotropic receptors are complex cation channels
False
TRUE OR FALSE: The AMPA and Kainate Receptors are simple cation channels found in glial cells & neurons that permit Na+ influx & K+ efflux.
True
What do you call a transient depolarization at the NMJ where each nerve impulse releases 60 ACh vesicles?
End-plate potential
What is the pathophysiology of Myasthenia Gravis?
Antibodies attach to ACh receptors
What is the pathophysiology of Eaton-Lambert Syndrome?
Antibodies attack the presynaptic calcium channels
TRUE OR FALSE: A clinical manifestation of myasthenia gravis is near normal strength at first then gradually weakens.
True
What do you call the NMJ found in smooth and cardiac muscles?
Synapse en passant
What cholinergic receptors are found in skeletal muscles?
Nicotinic
What cholinergic receptors are found in smooth muscles?
Muscarinic
What enzyme forms Ach?
Choline acetyltransferas
What do you call neurons that have norepinephrine as their transmitter?
Noradrenergic
From what amino acid does the catecholamines get synthesized from?
Tyrosine
What neurotransmitter is for temperature regulation, sensory
perception, and onset of sleep?
Serotonin
What neurotransmitter is for arousal and sexual behavior?
Histamine
Which of the following is an inhibitory neurotransmitter?
A. Glutamate
B. Aspartate
C. Glycine
D. GABA
D. GABA
What receptors are the ones with Mg++ ion block?
NMDA
What neurotransmitter is responsible for redness of the skin?
Substance P
What synaptic learning is responsible for short term memory?
Post-tetanic potentiation
What receptor is stimulated for long-term memory?
NMDA
Biological transducers that convert electrical energy to chemical energy
Neurotransmitters
Which of the following are excitatory NTs?
A. Glutamate
B. Aspartate
C. Glycine
D. GABA
E. A and B
F. A, B, and C
F. A, B, and C
In the bronchioles, norepinephrine will act via ___ and bronchodilation results.
Alpha 1 (for respiratory tract)
In the vascular system, norepinephrine will act via ___ and vasoconstriction results.
Alpha 2 (for blood vessels)
In the chambers of the heart, norepinephrine will act via ___ to produce faster heart rate and good quality contractions.
Beta 1 and Beta 2
Receptors that decrease cAMP and increase potassium
conductance, potassium exits the cardiac muscle
and is hyperpolarized. These receptors decrease activity of the
heart and come from innervation of vagus nerve.
M2 receptors (Muscarinic 2)
When ACh will be exocytosed, it is acted upon by an enzyme in the postsynaptic membrane called ___ to break it down into choline and acetate.
acetylcholinesterase
A neurotransmitter released by endothelium of blood vessels. It acts as a vasodilator and it is used in the management of acute hypertension. It also mediates long-term depression in synaptic plasticity and learning.
Nitric oxide (NO)
Serotonin (5-HT) is inactivated by ___
monoamine oxidase (MAO)
Dopamine has 5 receptors. Enumerate those that increase and those that decrease cAMP.
Increase cAMP: D1 & D5
Decrease cAMP: D2, D3, & D4
TRUE OR FALSE: Norepinephrine has more affinity to the beta adrenergic receptors.
False
When there is epinephrine in an area, what occurs?
(+) chronotropic effect, (+) inotropic effect
To form acetylcholine in the presynaptic cell, choline is combined with ___ which will be acted upon by choline acetyltransferase
Acetyl-CoA (acetyl coenzyme A)
Cocaine inhibits ___ uptake which creates hallucination
dopamine
In the peripheral nervous system, once a nerve gets
denervated (underwent wallerian degeneration), the muscle is contracting uncontrollably but is a nonfunctional contraction, known as ___
Fasciculations
Betablockers, with the suffix -olols, block the binding of ___ to beta receptors. These are considered good antihypertensive drugs.
Norepinephrine