ANS anatomy and physiology Flashcards
physiology of PNS on muscarinic receptor activation in the heart
- Decreased heart rate and av conduction and rate via effects on nodal cells
- Reduced atrial contractility via cardiac muscle
physiology of PNS on muscarinic receptor activation on vascular
- vasodilation M3 via endothelial cells
Note: M3 receptors are not innervated- activation of the PNS does not result in vasodilation
They can be activated by muscarinic agonist drugs
mneumonic of muscarinic activation
Bradycardia
Bronchospam
Salivation Lacrimation Urination Defication Gi- cramping emesis Eye-miosis
a Persons HR and contraction increase along with a increase in force of contraction. Which adrenergic receptor was activated
beta 1
Cutaneous, mucous membranes, splanchnic vessels are mediated by what adrenergic receptor?
alpha 1
Vasoconstriction mediate by _______ receptors contributes significantly to increase in total peripheral resistance
alpha 1
Skeletal muscle is mediated by what to adrenergic receptors?
alpha 1 and beta 2
Which adrenergic receptor mediates vasoconstriction and which does vasodilation
alpha 1 for constriction
beta 2 for dilation
If B2 receptors are activated what will happen to the blood flow (increase/decrease) to muscle and what will happen to the peripheral resistance (increase/decrease)
- Increase
2. Decrease
Renal vasculature is mediated by which two adrenergic receptors?
D1 and alpha 1
D1 receptor cause what (vasodilation or vasoconstriction)
Vasodilation
When someone has a very high dose of DA _______ gets released causing __________ via ________ receptors
- Norepinephrine
- Vasoconstriction
- alpha 1
BP is mediated by 3 adrenergic receptors which ones are they?
alpha 1
beta 1
beta 2
What kind of heart rate can occur which is considered a reflex to alpha 1 stimulation
bradycardia, alpha 1 cause vasoconstriction and thus increase in Total peripheral resistance and Blood pressure
The heart primarily consists of what kind of adrenergic receptor?
B1 which increases HR and force of contraction
If Beta 2 adrenergic receptors are innervated total peripheral resistance decrease causing BP to decrease so what kinds of reflex (HR) could occur
Tachycardia to try and increase CO
Someone just opened relaxed their bronchial smooth muscle aka bronchodilation what receptor did they activate?
beta 2, just like with the heart beta 2 cause vasodilation and arteries have smooth muscle so beta 2 smooth muscle
Say you wanted someone to suffocate and make it look like an accident you would want to switch their beta 2 agonist with what type of adrenergic receptor?
an alpha 1 receptor because it cause constriction… not sure if this would work but might help it stick
During sympathetic innervation you want you eyes to dilate so you can see everything. what adrenergic receptor is responsible for this?
alpha 1 cause mydriasis
When someone has glaucoma they have increased intraocular pressure and to help with this you give timolol drops. Knowing this, what adrenergic receptor is responsible for increased production of aqueous humor?
beta receptors because timolol is a beta blocker
A decrease in neurotransmitter release with presynaptic nerve terminals is caused by what adrenergic receptor?
alpha 2
Relaxation of the smooth muscle in the GI tract is caused by what two adrenergic receptors?
beta 2 and beta 3
If someone has just had a release of the adrenergic alpha 2 receptor will they be able to have contraction of smooth muscle in the GI tract?
No because alpha 2 is an inhibitory adrenergic receptor so it stops the release of ach and thus no ach mediated muscle contraction
If a gland is unable too secrete due to the inability of the release of Ach to act on Ach mediated muscle contraction, what adrenergic receptor do you think is responsible?
alpha 2 because of its effect on presynaptic
Match the following i.e number with letter
- uterine smooth muscle
- uretal sphincter, bladder base, prostate
- bladder wall musculature
- ejaculation
A. Alpha 1
B. beta 2 and 3 promoting urine
c. Beta 2 causing relaxation
d. Alpha 1 causing contraction
1 and C
2 and D
3 and B
4 and A
Activation of what adrenergic receptor causes a marked tremor (hint propanolol is used to treat essential tremors)
Beta-2 receptor
Beta 2 adrenergic receptor has what effect on metabolism
increased blood glucose
your running from the bear so you need glucose for energy so your sympathetic nervous system kicks in activating Beta 2
You have been running from a beast for a long time and your out of glucose so now you want to break down fat. What adrenergic receptor is activated for this?
beta 3
For some reason your body secretes way to much insulin so you want to decrease this. What adrenergic receptor should you activate?
alpha 2 will decrease insulin secretion
Well damn now you body doesn’t secrete enough insulin which adrenergic receptor do you need to now activate?
beta 2
Nicotinic come from autonomic ganglia. what is their effect on cardiovascular
primarily sympathetic via adrenal epi release or neuronal NE release
Nicotinic receptor effects on GI/urinary tract
primarily PSNS effects via postganglionic acetycholine release
this increases GI motility, nausea, vomiting, diarrhea, urination
Nicotinic effects on brain
- Mild alerting effect
- Activates “reward” pathway in limbic system
- Convulsion can occur at toxic dose
How do direct agonists drugs work?
mimicking the neurotransmitter action at the receptor.
So how does an antagonist drug work?
Blocking the neurotransmitter action at the receptor
how do parasympatholytic and sympatholytic agents work?
They change the normal action of the neurotransmitter aka indirect agonist
- increase or decrease synthesis
- Increase or decrease storage and release
- Block inactivation after release
Would you rather use drugs that act post-synaptically or pre-synaptically?
Post-synaptically because they have the greates selectivity and most clinically useful. They act at specific receptor subtypes as either agonist or antagonist
How do drugs that act pre-synaptically work?
by altering synthesis, storage or release, or inactivation mechanism
Why are pre-synaptically drugs less useful?
because they effect all synapses for neurotransmitter regardless of which receptor subtype is present
You gave your patient Pyridostigmine to treat myasthenia gravis by inhibiting the breakdown of Ach. is this a indirect cholinergic agonist or direct cholinergic agonist
indirect because it stops cholinesterase from breaking down ACH so therefore indirectly assisting Ach
