5.3 Flashcards
What is another name for motor neurons?
Cholinergic neurons
Why are motor neurons called cholinergic neurons?
Because acetylcholine is their main neurotransmitter
Are motor neurons in skeletal muscles excitatory or inhibitory?
Excitatory
What is the single main receptor that serves the SNS?
Nicotinic acetylcholine receptor (nAChr)
What does SNS stand for?
Somatic nervous system
What compound in tobacco cigarettes stimulates the nAChr?
Nicotine
What ions does the nAChr affect?
Na+ influx and K+ efflux (simultaneously)
The structure of nicotine is similar to what neurotransmitter?
Acetylcholine
What does ANS stand for?
Autonomic nervous system
What are the two division of the ANS?
Sympathetic and Parasympathetic
What is the sympathetic division responsible for?
Fight-or-flight
What is the parasympathetic division responsible for?
Rest-and-digest
What is the main receptor controls both divisions of the ANS (signals being sent by the CNS)
Acetylcholine
What neurotransmitter in the sympathetic division readies the body for flight-or-flight?
Norepinephrine
What neurotransmitter in the parasympathetic division readies the body for rest-and-digest?
Acetylcholine
How does NE affect the heart vs other organs?
Excitatory for the heart (increase heart rate), inhibitory for other organs (decrease function - gut for example)
Is acetylcholine excitatory or inhibitory for the heart?
Inhibitory (decrease heart rate)
What does ENS stand for?
Enteric Nervous System
What is the purpose of ENS neurons?
To detect mechanical and chemical conditions in the gastrointestinal system;
Control the mixing of intestinal contents; secrete digestive enzymes
What are the chief neurotransmitters in the ENS (according to text)
Serotonin and dopamine
What is an activating system?
Neural pathways that coordinate brain activity through a single
neurotransmitter; its cell bodies lie in a brainstem nucleus; axons are
distributed through a wide CNS region.
What brain regions are innervated in the cholinergic activating system?
midbrain nuclei, basal forebrain nuclei, frontal cortex, corpus callosum.
What parts of the brain are innervated in the dopaminergic activating system?
ventral tegmentum, substantia nigra, cerebellum, caudate nucleus, nucleus accumbens in the basal ganglia
What are the parts of the brain innervated in the noradrenergic activating system?
Locus coeruleus, thalamus
What parts of the brain are innervated in the serotonergic activating system?
Raphe nuclei
Where in the brain is acetylcholinesterase especially dense?
Basal ganglia
What behaviors does the cholinergic activating system participate in?
Waking, attention, memory
Alzheimer disease
Degenerative brain disorder related to aging; first appears as progressive
memory loss and later develops into generalized dementia.
What can be seen in the brain of a patient with Alzheimer’s?
Loss of cholinergic neurons, damage to neocortex
What are 2 treatment strategies for someone with Alzheimer’s?
Medication to inhibit AChE or to increase nicotinic receptors
What are the two pathways in the dopaminergic activating system?
Nigrostriatal dopaminergic system and mesolimbic dopaminergic system
What is the role of the nigrostriatal system in the body?
Coordinating movement
Parkinson’s disease
loss of dopamine neurons in the substantia nigra.
extreme muscular rigidity, rhythmic tremors
What is the role of the mesolimbic system in the body?
Impulse control
Has a role in addiction
Addiction
loss of impulse control
dopamine in the mesolimbic system most affected
stimulating mesolimbic system enhances responses to environmental stimuli
Schizophrenia
Behavioral disorder characterized by delusions, hallucinations,
disorganized speech, blunted emotion, agitation or immobility, and a host
of associated symptoms.
Excessive mesolimbic dopaminergic activity
What roles does the noradrenergic system have in the brain/body?
Learning (stimulating neurons to change structure)
Healthy brain development, organizing movement
Noradrenergic neuron
a neuron that uses norepinephrine as its transmitter
Major depression
Characterized by prolonged feelings of worthlessness and guilt, the
disruption of typical eating habits, sleep disturbances, a general slowing
of behavior, and frequent thoughts of suicide;
decreased activity of noradrenergic neurons
Mania
Disordered mental state of extreme excitement.
increased activity of noradrenergic neurons.
ADHD
associated with decreased noradrenergic neural activity
What roles does the serotonergic activating pathway play in the body?
Wakefulness, learning, mood
What disorders are relating to the serotonergic activating pathway?
Depression and OCD (low activation), schizophrenia (increased activation), SIDS, sleep apnea
OCD
Behavior characterized by compulsively repeated acts (such as hand
washing) and repetitive, often unpleasant, thoughts (obsessions).
