autonomic nervous system Flashcards
nervous system _______ the body activitiy to maintain _________ when there is a _______ to the _______ __________.
coordinates, homeostasis, change, environmental conditions
to able to mantain homeostasis, the nervous system must
- recognize the changes in the in internal and external environment
- process and integrate the perceived environmental changes
- react to the environmental changes by producing a response
nervous system has two major divisions which are
the central nervous system and the peripheral nervous system
the CNS consists of
brain and spinal cord
function of a brain
receives and process sensory information, initiates responses, stores, memories generates thoughts and emotions
function of a spinal cord
conducts signals to and from the brain, control reflex activities
PNS consists of
all nervous tissues outside the CNS such as sensory and motor neurons which we can afferent and efferent pathways.
sotamic nervous system controls
voluntary movements
autonomic nervous system controls
involuntary nervous responses
pathway of motor neurons
CNS to muscles and glands
pathway of sensory neurons
sensory organs to CNS
sympathetic division is also known as
fight or flight
parasympathetic division is also known as
rest or digest
autonomic nervous system controls
smooth muscles, cardiac muscles, exocrine glands and some endocrine glands
what is a synaptic gap/ synapse
a gap between communicating neurons which are presynaptic neuron and postsynaptic neuron
what are the two type of synapses
1) adrenergic
2) cholinergic
what are neurotransmitters
chemical for neurons to communicate
examples of neurotransmitters
Norepinephrine, Epinephrine, Acetylcholine
what are receptor
a molecular structure or site on the surface of a cell that binds with substances such as hormones, antigens, drugs or neurotransmitters
what are the functions of autonomic nervous system ?
- controls involuntary responses by influencing organs, glands and smooth muscles
Autonomic system consist of 2 divisions which are
1) sympathetic nervous system
2) parasympathetic nervous system
sympathetic nervous system is activated in conditions of __________ and produces ____________
stress, fight or flight response
parasympathetic nervous system activated in ______________ circumstances and produces a ______________ state.
non-stressful circumstances , rest-and-digest state
what is the synapse & receptor of sympathetic division called?
adrenergic synapse , adregenic receptors
what is the synapse & receptor of parasympathetic division called?
cholinergic synapse & cholinergic receptors
sympathetic neurotransmitter involves are
1) norepinephrine (noradrenaline) / NE
2) Epinephrine (adrenaline)
neurotransmitters involved in parasympathetic division
acetylcholine, ACH
receptors involved in sympathetic division
adrenergic receptors which are divided into :
- alpha-1 receptors
- alpha-2 receptors
- beta-1 receptors
- beta-2 receptors
receptors involved in parasympathetic division
- nicotinic receptors
- muscarinic receptors
examples of changes in body during sympathetic
- hear rate increases
- bronchial tubes dilate
- pupil dilate
- saliva production reduced
- glycogen is converted to glucose
- inhibit activity in stomach
examples of changes in the body during parasympathetic
- pupils constrict
- heart rate down
- digestion takes place
- increase urine
- saliva increase
- stimulate activity in stomach
ANS drugs produce their primary therapeutic effects by working like a neurotransmitter either ______ the natural chemical function or _________/ ________ the natural chemical function
mimic, block
ANS drugs bind to the __________ site on the __________ neuron
receptor site, post-synaptic neuron
ANS drugs bind to the receptor site on the post-synaptic neuron to
- stimulate the action of the autonomic nerves (agonist)
2. block the action of autonomic nerves (agonist)
What adrenergic agonist / sympathomimetics dugs does?
- stimulate the action of the sympathetic nervous system .
- drugs that partially or completely mimic the effects of the sympathetic nervous system
- this group of medication induce the fight or flight response by stimulating both alpha beta adrenergic receptors
what adrenergic antagonist/ sympatholytics drugs does?
- inhibit the action of the sympathetic nervous system
- drugs that block the effects of sympathetic nervous system
- result in inhibition of sympathetic nervous system and the effects may be similar to parasympathomimetics
what cholinergic agonist/ parasympathomimetics drugs does?
- stimulate the activity of the parasympathetic nervous system
- symptoms produced mimic the rest or digest response
what cholinergic antagonist/ anticholinergic/ parasympatholytics drugs does?
- inhibit the activity of the parasympathetic nervous system
- the drugs blocks the effect of parasympathetic nervous system
- result in inhibition of parasympathetic nervous system and the effects may be similar to sympathomimetics
drugs that produced the symptoms of rest-or-digest response
cholinergic agonist/ parasympathomimetics
drugs that blocks the effect of parasympathetic nervous system
cholinergic antagonist, anticholinergic , parasympatholytics
effect of neurotransmitters on the sympathetic nervous system- on heart and kidney
stimulation of beta-1 receptors increases heart rate and force of contraction. hence it can be used for treatment of heart failure and cardiogenic shock.
effect of neurotransmitters on the sympathetic nervous system ( on blood vessels, lungs and uterus )
stimulation of beta-2 receptors causing bronchodilation and uterus relaxation . Hence it can be used for treatment of asthma and premature labour contractions
effect of neurotransmitter on the sympathetic nervous system - postsynaptic memebrane of effector organs EXCEPT HEART
Activation of vascular smooth muscle receptors causes vasoconstriction, leading to an increase in blood pressure, hence it can be used for hypotensive and anaphylactic shock. ∙ α1 & α2 activation: Mydriasis (dilation of pupils)
effect of neurotransmitter on the sympathetic nervous system - presynaptic adrenergic nerve terminal
activation of alpha-2 receptors at the presynaptic adrenergic nerve terminal inhibits release of norepinephrine and causes vasodilation . Hence it can be used for hypertensio.
actions brought about alpha1
Stimulates α1 adrenergic receptors of the vascular smooth muscle,
resulting in vasoconstriction (vasopressor) and increased systemic blood
pressure.
actions brought about beta 1
Stimulates β1 adrenergic receptors of heart, resulting in increased heart
rate (chronotropic) and myocardia contractibility (inotropic).
actions brought about beta 1
Stimulates β2 adrenergic receptors of the vascular smooth muscle and
bronchial smooth muscle, resulting in vasodilation and bronchodilation
