Autonomic nervous system pharmacology Flashcards
Of what components does the central nervous system consist of?
brain and spinal cord
The peripheral nervous system can be subdivided between autonomic and somatic, describe the differences
sympathetic is arousing and parasympathetic is calming
What is the difference between the somatic and the autonomic nervous system?
The autonomic nervous system is repsonsible for actions inside of the body (what happens when you eat a sandwich), the somatic nervous system is active when you feel pain
The flight or fight reaction is dependent on adrenaline, true or not true
no not true, the initial reaction is not dependent on adrenaline
What happens when cortisol is released?
Breakdown of muscle proteins and increase in glucose levels. These muscle breakdowns are rectified by the parasympathetic nervous system
What does functional antagonism mean?
It is an interaction between the para and sympathetic nervous system on one organ. The different approaches to a neuron between the para and the sympathetic nervous system
Where does the pre and post ganglionic neuron come from in the sympathetic nervous system?
The preganglionic neuron comes from the cns in the lateral horn and the post lies in the pns
Where does the pre and post ganglionic neuron come from in the parasympathetic nervous system?
The pre ganglionic neuron comes from the higher part in the brainstem, medulla oblongata or the sacral spinal cord and the postganglionic neuron travel in the pns.
What is the difference in length of the neurons in the para and sympathetic nervous system?
In the para: the preganglionic neuron is very long and the post short
in the sympa: the pre is short and the post is long
The autonomic nervous system can be subdivided into
the para and sympathetic nervous system
Where are enzymes made?
These are made in the cell body and thus take a long time to replace
Acetylcholine has which receptor?
nicotinic receptor
Name what happens with the adrenal medulla
There is a preganglionic neuron, but no post. It goes directly from the cns to the adrenal medulla that will release epinephrine and norepinephrine into the bloodvessel
Describe the other exception of sweat glands
The preganglionic neuron goes to the acetylcholine receptor which is the same situation for the parasympathetic nervous system.
What does heterotropic interaction mean?
This means that the sympathetic nervous sytem tries to downtune the effect of the parasympathetic nervous system on the tissue and the other way around.
What does a homotropic interaction mean?
There is an inhibitory effect on the presynaptic terminal in the form of autoreceptors. These give the presynaptic terminal that it has to stop release neurotransmitters
What does co-transmission mean?
a single neuron releases multiple neurotransmitters to communicate with its target cells. This allows for a more nuanced and complex signaling system in the nervous system. The different neurotransmitters released may have distinct effects on the receiving cells, contributing to the diversity of neuronal communication.
How are neurotransmitters broken down? (3)
- reuptake by the presynaptic neuron
- an enzyme that breaks it down
- uptake by other cells
How is acetylcholine broken down as a neurotransmitter?
Acetylcholine is broken down by an enzyme called acetylcholineasterase
In which cells does reuptake by other cells take place when talking about the ending of neurotransmission?
astrocytes are involved by taking up the neurotransmitter
How is acetylcholine formed?
acetyl-coenzyme A and choline will form ACh and this is done by choline acetyltransferase
By which drug can the formation of vesicles of acetylcholine in the presynaptic neuron be blocked?
vesamicol
Name the pre and postsynaptic receptors of ACh
- muscarinic receptors
- nicotinic receptors (of the skeletal muscle)
How is ACh broken down?
This is done by acetylcholinesterase and this is broken down into choline and acetate.
Where is ACh produced and as a neurotransmitter used by?
-postganglionic parasympathetic neurons
-some postganglionic sympathetic neurons such as sweat glands and the adrenal medulla
- preganglionic (para)sympathetic neurons
- motor neurons innervating straited muscle tissue
-cholinergic neurons CNS
Name the 5 types of muscarinic receptor types and where you can find them
1,4,5: cns
2: heart
3: smooth muscle cells
Name the 2 types of the nicotinic receptor
- the skeletal muscle version: receptor m
- the cns: receptor n
Explain how nicotinic receptors work
When there is an activation of the receptor, the channel opens and there is an influx of sodium (Na). this is an ionotropic receptor.
Explain how muscarinic receptors work
Muscarinic receptors are G-protein coupled receptors and these are metabotropic. When you activate the receptor, a second messenger cascade will follow.
Which receptor is faster and why? nocotinic or muscarinic
Nicotinic receptors are faster as these are ionobotropic and not metabotropic and only need to open the gates
name the 4 classes of drugs that have a direct effect on ACh receptors (agonist or antagonist)
- parasympathicomimetics (agonist)
- parasympathicolytics (antagonist)
- Ganglion-blockers (antagonist)
- neuromuscular inhibitors (antagonist or agonist)
What does the parasympathicolytics do to ACh?
These are an antagonist and counteract/reduce the effects of activation of the parasympathetic nerves
What do ganglionic-blockers do?
They are antagonist and block all neurotransmission on the level of the ganglia
What do neuromuscular inhibitors do to ACh?
They bind the nicotinic receptor on skeletal muscle and thereby influencing control of these muscles.
What is the definition of parasymathicomimetics?
A group of drugs that selectively bind to ACh receptors as agonists and therefore elicit the same effects as activation of the parasympathetic system which means activation of the sweat glands (sympathetic nog steeds) and parasympathetic system
What is the difference between an agonist and an antagonist
An agonist activates or enhances a biological response, while an antagonist blocks or inhibits a biological response.
GIve examples of parasympathicomimetics (2 direct and 1 indirect)
direct:
1. carbachol
2. muscarine
indirect:
1. AChE inhibitors