ANS Neurotransmitters Flashcards
Which autonomic neuron releases acetycholine and which releases noradrenalin (norepinephrine)?
cholinergic produces ACh and adrenergic produces noradrenalin
Where is ACh stored and how is it released?
It is stored in synaptic vesicles and released by exocytosis.
How does ACh reach the cholinergic receptors to cause excitation or inhibition of the postsynaptic cell?
diffuses across the synaptic cleft
Where is the location of the only sympathetic postganglionic neurons found among cholinergic neurons?
sweat glands
What type of neurons make up the adrenergic neurons?
most sympathetic postganglionic neurons
They are integral membrane proteins located in the plasma membrane of the postsynaptic neuron or effector cell. What are they?
neurotransmitter receptors
What are the 2 types of cholinergic receptors and what distinguishes them?
Nicotinic (nicotine mimics ACh when it binds to it) and muscarinic (muscarine mimics ACh when it binds to it)
Nicotine can activate muscarinic receptors. T or F?
F
What inactivates ACh?
acetylcholinestrerase
Which receptors causes the depolarization (excitation) of the postsynaptic cell?
nicotinic receptor and muscarinic receptor
Which receptor causes the hyperpolarization(inhibition) of the postsynaptic cell?
muscarinic receptor
What effect does the binding of ACh to the muscarinic receptors of smooth muscle sphincters in the gastrointestinal tract have?
Causes relaxation
What effect does ACh have on the sphincter muscles of the eye?
contraction (miosis)
What is the acronym for the result of activating muscarinic receptors and what do they mean?
DUMBELS
Defecation, Urination, Miosis, Bronchoconstriction, Emesis (vomiting), Lacrimation, Salivation
Adrenergic receptors are activated by?
norepinephrine from sympathetic postganglionic neurons; epinephrine and norepinephrine released as hormones from adrenal medulla
What are the 2 types of adrenergic receptors?
alpha and beta receptors
Activation of which adrenergic receptors results in excitation?
alpha 1 and beta 1
Activation of which adrenergic receptors results in inhibition?
alpha 2 and beta 2
The activation of beta 3 adrenergic cells in brown adipose tissue causes?
thermogenesis
Why does effects triggered by adrenergic neurons usually last longer than effects due to choligernic?
because norepinephrine lingers in the synaptic cleft longer than ACh
How is norepinephrine inactivated?
reuptake by axon; COMT and MAO enzymes
what is the substance that binds to a cell receptor to block agonists from binding to it?
antagonist
Where are beta 1 receptors located, what binds to them and what blocks their effect?
heart; adrenalin; beta blockers
Where are alpha 1 receptors located, what binds to them and what blocks their effect?
blood vessels of sympathetic target organs; adrenaline; alpha blockers
Body organs usually receive dual innervation from both divisions of the ANS. T or F?
T
The balance between sympathetic and parasympathetic activity of the ANS is known as?
autonomic tone
Which part of the brain regulates autonomic tone?
hypothalamus
If the postganglionic neurons release different neurotransmitters, what so the effector organs possess?
different adrenergic and cholinergic receptors
What is the acronym for structures that only receive sympathetic innervation?
SKABAS (sweat glands, arrectores pilorum muscles, kidneys, adrenal glands, spleen, and blood vessels
Which division dominates during physical and emotional stress and what are the Es of this division?
sympathetic division; exercise, excitement, emergency, embarrasement
Where does constrictions occur during fight or flight response?
abdominal viscera; skin
what happens to the airways and pupils during fight or flight?
dilate
Blood glucose levels rise due to glycogenolysis by liver cells. T or F?
T
why does sympathetic stimulation last longer than parasympathetic?
because acetycoline is quickly degraded while adrenaline has an extensive divergence of sympathetic postganglionic axons
What is the acronym for parasympathetic response?
SLUDD; Salivation, Lacrimation, Urination, Defecation, Digestion
The overall components of an autonomic reflex arc is not the same as a somatic reflex arc. T or F?
F
The acronym for the component of the autonomic reflex arc is?
MISES; motor neurons, integrating center, sensory neuron, effector, sensory receptor
The distal end of an autonomic reflex arc that responds to stimuli and produces changes is known as?
The receptor
What conducts nerve impulses from receptors to the CNS?
sensory neurons
Where are the cell bodies of viscera sensory neurons located?
sensory ganglia of associated cranial nerves and dorsal root ganglia of the spinal cord
Where would you find most integrating centers for relaying signals from sensory neurons to motor neurons?
hypothalamus and brain stem; fewer in the spinal cord
which 2 motor neurons connect the CNS to the effector?
preganglionic and postganglionic neuron
Which myelinated neuron conducts impulses from the CNS to an autonomic ganglion?
preganglionic neuron
What are the effectors in an autonomic reflex?
smooth muscle, cardiac muscle, and glands
The control and integration center which receives sensory input, provides output to autonomic centers of the brain stem and spinal cord, and connected to both the sympathetic and parasympathetic divisions of the ANS, is known as?
hypothalamus
polygraph testing relies on which autonomic responses to detect lies?
sweating, blood pressure, heart rate, and breathing rate
It enables individuals to learn to exercise a degree of conscious control over the monitored parameter and has been found to be effective for treating headaches and migraine. What is it?
Biofeedback
This condition is due to excessive sympathetic stimulation of smooth muscle in the arterioles of digits leading to lack of blood (ischemic) in those digits. What is it?
Raynaud disease
Which anticholinergic drug blocks parasympathetic effects (such as salivation) and serves as an antidote for chemical warfare that inactivate acetylcholinesterase?
Atropine
Which anticholinesterase drug is used to inhibit the enzyme cholinesterase preventing the breakdown of ACh and treating myasthenia gravis (impaired skeletal muscle)?
Neostigmine
Tricyclic antidepressants help relieve depression by doing what?
prolong the activity of norepinephrine on the postsynaptic membrane
How does MAO inhibitors help with relieving depression?
blocking MAO that inactivate norepinephrine released into synapses of postganglionic sympathetic division neurons
