ANS Flashcards
ANS is centrally regulated by nuclei in: (4)
Medulla
Pons
Hypothalamus
Spinal cord
Afferents tracts affecting CNS classified as: (4)
- Visceral afferents
- Somatic afferents
- Central chemo afferents
- Cognitive components
Divisions of ANS
Sympathetic NS
Parasympathetic NS
SNS is designed for _____, some examples include _____
Coping with acute challenges
Ex: HR, BP
PSNS regulates (2)
Metabolism
Cardiovascular function
** More localized in action**
Preganglionic neurons are ________ fibers that primarily use _____ (a neurotransmitter)
Cholinergic
ACh
Post-ganglionic fibers have receptors that can bind
ACh or nicotine
What are cholinergic-nicotine, N2 receptors?
Post-ganglionic cholinergic receptors that bind nicotine
Post-ganglionic fibers are _____ and primarily use ____ (a neurotransmitter)
Noradrenergic
Norepi
When post-ganglionic receptors are activated, it allows _____ because the receptors are ______
Inward current of Na and Ca
Modified ion channels
Adrenoceptors are coupled to
G protein activation
Isoforms of adrenoceptors determines
Specificity of the response to adrenergic stimulation
α1 Adrenoceptors
Vasoconstriction in VSM
β2 Adrenoceptors
Found in heart and smooth muscle beds
Vasodilation
β1 Adrenoceptors
Increase chronotropy (HR) and inotropy (contractile force) in Heart
Preganglionic SNS fibers termineate in ______ and synapse with ________
Adrenal medulla
Chromatin cells
Chromatin cells synthesize _____ and are stimulated by _______ to release it into circulation
Epi and Norepi
ACh
Epi has a high affinity for _______ adrenceptors
α and β
At low doses of epi, it binds to
β2 adrenoceptors to induce vasodilation
At all doses of epi, it’s a strong
β1 agonist
Norepi is a strong
β1 and α1 agonist
Lower doses of norepi, you have a
Pressed effect- mediated vasoconstriction from α1
Beta blockers
β1 adrenoceptor antagonists
End in -olol
Examples of beta blockers
Atenolol and Metoprolol
High specificity against β1
SNS activated during
Cognitive and/or physical stress
Sympathomimetics are compounds that
Stimulate adrenceptor activity (agonists)
Alpha blockers suppress _____ so they’re helpful for _____
Vascular smooth muscle tone
Reducing hypertension
Propranolol
Beta blocker
Non-specific
Beta blockers are used to
Control angina and hypertension
Preganglionic PSNS fibers originate in the _______ of the ______
Brainstem and sacral region
Spinal cord
Most preganglionic PSNS fibers are in the
Vagus nerve
Effectors of PSNS have ____ receptors that can bind _____ and are ______ receptors
Cholinergic-muscarinic (CM)
Muscarine
G protein coupled
ACh binds to _____ receptors on the _______ membrane
Cholinergic (muscarinic or nicotinic)
Post-synaptic
How to prevent prolonged activation of cholinergic receptors on post-junctional membrane?
ACh is degraded by a cholinesterase
Elevated SNS tone leads to
Increased HR
PSNS activity leads to
Decreased HR
Where is PSNS innervate on primarily located?
SA and AV nodal tissues
Av node is the juncture between the ______ and ______
Right and left atria
Ventricles
Effector: contract bronchial smooth muscle
What’s the SNS effect and receptor?
What’s the PSNS effect and receptor?
Inhibitory, β2
Stimulatory CM
Effector: contraction, cardiac muscle
What’s the SNS effect and receptor?
What’s the PSNS effect and receptor?
Stimulatory, β1
N/a
Effector: heart rate, SA node
What’s the SNS effect and receptor?
What’s the PSNS effect and receptor?
Stimulatory, β1
Inhibitory, CM2
Effector: renin secretion, kidney
What’s the SNS effect and receptor?
What’s the PSNS effect and receptor?
Stimulatory, β1
N/a
Effector: glycogenolysis, gluconeogenesis (liver)
What’s the SNS effect and receptor?
What’s the PSNS effect and receptor?
Stimulatory, β2
N/a
Effector: adipocytes, lipolysis
What’s the SNS effect and receptor?
What’s the PSNS effect and receptor?
Stimulatory, β3
N/a
Effector: contraction, skeletal muscle force
What’s the SNS effect and receptor?
What’s the PSNS effect and receptor?
Stimulatory, β1
N/a
Effector: contraction, VSM
What’s the SNS effect and receptor?
What’s the PSNS effect and receptor?
Stimulatory, A1; Inhibitory, β2 (skeletal muscle)
Generally non, microcirculation, inhibition mediated by VIP
Effector: pancreas (β cells), insulin secretion
What’s the SNS effect and receptor?
What’s the PSNS effect and receptor?
Initiatory, β2
Stimulatory, CM
