Autonomic Nervous System (ANS) Pharmacology: Flashcards
What is the primary function of the autonomic nervous system (ANS)?
Regulates the internal environment to maintain homeostasis.
Is the ANS voluntary or involuntary?
Mostly involuntary.
How does the ANS regulate consumption responses?
Controls hunger and thirst.
What are three key physiological functions modulated by the ANS?
Digestion (blood flow, urination, defecation) and body temperature regulation, blood pressure
The ANS responds to external cues to activate a what response?
fight or flight responses
How do the parasympathetic and sympathetic systems interact?
They often act counter to each other.
Where do parasympathetic nerves originate?
Cranial nuclei (III, VII, IX, X) and sacral spinal cord segments.
What is the general length of parasympathetic preganglionic and postganglionic neurons and where do they synapse?
Preganglionic:
- Long
- synapse in peripheral gangila near or in target organ
Postganglionic:
- Short
- extend into targets
What organs are targeted by the parasympathetic nervous system?
Intrinsic eye muscles, salivary and lachrymal glands, heart, lungs, pancreas, stomach, intestine, colon, sexual organs, kidneys, bladder.
What neurotransmitter is released by parasympathetic preganglionic neurons inorder to signal?
Acetylcholine (ACh).
What receptors do parasympathetic postganglionic neurons express?
Nicotinic ACh receptors (nAChR).
What receptors are found on parasympathetic target organs?
Muscarinic ACh receptors (mAChR).
What is another name for the sympathetic nervous system?
Thoracolumbar division.
Where do sympathetic preganglionic nerves originate?
Intermediolateral nuclei of the thoracolumbar spinal cord (T1-T3).
What is the length of sympathetic preganglionic neurons?
Short.
Where do sympathetic preganglionic neurons synapse?
Paravertebral sympathetic ganglia, prevertebral ganglia, or the adrenal medulla.
What organs are targeted by the sympathetic preganglionic nerves system?
sweat and salivary glands, heart, lungs, pancreas, stomach, intestine, colon, sexual organs, kidneys, bladder.
How many postganglionic neurons can a single sympathetic preganglionic neuron activate?
Up to 20, leading to signal amplification and generalization.
What neurotransmitter is released by sympathetic preganglionic neurons?
Acetylcholine (ACh).
What type of receptors do sympathetic postganglionic neurons express?
Nicotinic ACh receptors.
What neurotransmitters are released by most sympathetic postganglionic neurons inorder to signal?
Epinephrine (EPI) or Norepinephrine (NE).
What type of receptors are found on sympathetic target organs?
Alpha (α) and Beta (β) adrenergic receptors.
How does the sympathetic nervous system communicate between neurons its target organs?
Preganglionic neurons release ACh → Postganglionic neurons express nicotinic receptors → Postganglionic neurons release EPI/NE → Target organs express α or β adrenergic receptors.
What is the primary method of communication in the autonomic nervous system (ANS)?
Neurotransmitter release.
What are the two major neurotransmitters in the ANS?
Acetylcholine (cholinergic)
Norepinephrine
What is epi often referred to as?
trade name was adrenalin to they are referred to as adrenergic
What is the difference between NE and Epi in terms of function?
NE acts mainly as a neurotransmitter, while Epi acts mainly as a neurohormone.
What are the two types of cholinergic receptors?
Nicotinic ACh receptors and Muscarinic ACh receptors.
How do muscarinic ACh receptors function?
G protein-coupled receptors signaling through second messengers to excite the neuron
How do nicotinic ACh receptors function?
ion channels allowing sodium influx when activated to excite the neuron
