Exam II Stress and the Autonomic Nervous System Flashcards
homeostasis
the purposeful maintenance of a stable internal environment maintained by coordinated physiologic processes that resist change.
autonomic nervous system
(acute stress response)
sympathetic and parasympathetic
PNS: -afferent (arrive)
-efferent(exit) -somatic
-autonomic -2-neuron pathway
-smooth or cardiac muscles, glands, or GI neurons
-ANS allows signalling to go to an effected organ:
integrating center=ANS=>Effector (what generates the response)
sympathetic NS
Adrenergic receptors --> sensitivie to E and NE
-alpha and subtypes
-beta and subtypes
DIFFUSE AND PROLONGED
preganglionic neurons are SHORT
ACh is at all preganglionic receptorsparasympathetic NS
cholinergic receptors–> sensitive to ACh
-IONOTROPIC - nicotinic (basically sodium channels)
-METABOTROPIC - muscarinic (on target tissues - G protein coupled receptor)
REST and DIGEST
preganglionic neurons are LONG
Ach is at all receptors (pre and post)
synapses in an organ
perturbation
a deviation of a system, moving object, or process from its regular or normal state of path, caused by an outside influence
set point
homeostasis is a characteristic of a system that regulates its internal environment and tends to maintain a stable, relatively constant condition of properties. The normal value of a physiological variable is called its set point.
integrating center
the part of the mechanism that interprets and integrates information before autonomic nervous system causes an effect to regulate the response.
effector
the system or thing that generates the response
biologic response
nn
afferent
nn
efferent
nn
somatic
nn
ganglion
nn
pre-ganglionic
nn
post-ganglionic
nn
pre-synaptic
nn
post-synaptic
nn
acetylcoline
nn
cholinergic
NO such thing as a cholinergic uptake**
NE
nn
E
nn
chromaffin cell
most gang neurons - these are specialized - they dont have an axon that goes on to interact w a target cell, and when stim by Ach secrete E mostly (80% and 20%NE) into blood stream
- in that pathway they act **
- these can be classified as neuroendocrine cells since they release a hormone
adrenergic
nn
alpha adrenergic receptor
oo
beta adrenergic receptor
nn
nicotinic receptor
nn
muscarinic receptor
nn
ionotropic
nn
metabotropic
nn
factors determining response to cholinergic or adrenergic receptors
- concentration of NT/hormone
- receptor population of target cells
- specific nature of target cell
balance btw para and sym systems - the seesaw
- in many tissues there’s an interplay between the two tissues
- GI and Genitourinary: [phamacologically, muscle activity manipulated most ALWAYS by altering the PS activity, with Para medications (inhi or act) have a bigger impact on these systems than symp
adrenal cortex, negative feedback, and stress response
positive and negative feedback
- negative feedback means opposite (thermoregulation, shivering or sweating)
- positive feedback means more of the same (oxytocin and labor/delivery)
catecholamine reuptake
- cocaine - inhibits NET (nearly completely)
- Tricyclic antidepressants: inhibit NET: one way to influence adrenergic synpase activity is to inhibit reuptake of seratonin, and it can interact w all these diff receptors: alpha and muscarinic, etc receptors
- NE is a NT besides those involved in activation of the symp NS
- has benefits to depression, but has peripheral effects bc circulates in the blood (interacts w diff receptors)
- elderly patient may not benefit from antidepressant properties, but additional qualities that this med adds may not make this worth it as an antidepressant
alpha 2 agonist
catepressor chlonadine(?)
- if this is done in symp systems, will reduce BP
- centrally-acting drug
- major side effect: hypotensive and drowsy
dopamine
kidneys, guts, heart**
skeletal muscle vs smooth re: symp and para activity
-alpha receptors contraction of vascular smooth muscle and genitourinary smooth muscle
-as opposed to…
skeletal muscle - b2 receptors (blood vessels dilate)
local regulation of tissue and its metabolic or aerobic activity create more of an affect than systemic symp stimulation (which would cause vasoconstriction and dec. muscular activity)
