Flashcards in ANS: Stress Response Deck (19)
What are the components of the CNS?
2. Spinal cord
What do afferent nerves do?
Sensory neurons, deliver info from external environment to brain
What do efferent nerves do?
Motor neurons, deliver info from brain to peripheral structures
What does the ANS do?
Part of peripheral nervous system, regulates involuntary functions
What comprises the PSNS?
Arises from brain stem via CNS.
CN X Vagus controls 75% of PSNS functions. Also includes spinal and sacral nerves
What comprises the SNS?
Arises from the spinal cord via thoracic and lumbar areas.
Includes SNS specific neurotransmitters (catecholamines)
What are catecholamines?
Neurotransmitters associated with SNS
What are sympathomimetics?
Synthetic drugs that mimic cathecholamines to activate alpha, beta, dopaminergic receptors of SNS
How does neurotransmission work?
1. Impulse travels to presynaptic membrane
2. Presynaptic membrane releases NTs into the synapse
3. NTs fit onto specific receptor sites
4. Enough NTs attaching = organ effect
What NTs alpha adrenoceptors receptive to?
What types of alpha receptors are there and what do they effect?
Receptive to norepinephrine, epinephrine, dopamine
Alpha 1 receptors effect vascular smooth muscle. Vasoconstriction. Found in systemic vessels, heart, GI tract
Alpha 2 receptors provide negative feedback loop that usually inhibits release of catecholamines
What do alpha 2 agonists do?
Targets alpha 2 receptors, activates negative feedback loop, suppresses SNS, calms pt from anxiety, can decrease BP
What NTs are beta adrenoceptors receptive to?
What types of beta receptors are there and what do they do?
Receptive to epinephrine (B1), norepinephrine, dopamine
Beta 1 receptors effect the heart
1. Cronotropic (HR)
2. Inotropic (Contractility)
3. Dromotropic (Conduction)
Beta 2 receptors effect the lungs and will cause bronchodilation (smooth muscle relaxation)
What NTs are dopaminergic receptors receptive to? What does it do?
Receptive to dopamine. Effects blood vessels to kidney, kidney itself, causes slight diuresis via vasodilation
What NTs are present in the PSNS?
Acetylcholine attaches to cholinergic receptors to activate PSNS
What would an anti-cholinergic med do?
Suppresses effects of overactive PSNS (Glycopyrralate reduces secretions, drooling)
What does epinephrine primarily effect?
Primarily effects Beta 1 receptors and will increase HR, FOC, conduction. Give in cases of bradycardia, not so much with volume issues.
What med do you give to vasoconstrict the pt?
What med do you give to increase cardiac function or bronchodilate?