neuronal control of the CV and rest systems Flashcards
step 1 of neuronal function
neurotransmitters act on receptors in dendritic spines
step 2 of neuronal function
depolarisation
step 3 of neuronal function
action potential generation and propagation
step 4 of neuronal function
neurotransmitter release signals to:
- neurons
- glands
- muscles
CNS neurotransmittes
- glutamate
- GABA
- serotonin
- dopamine
- noradrenaline
PNS neurotransmitters
- noradrenaline
- acetylcholine
what does the ANS do
regulates certain body processes that work without conscious effort
eg. blood pressure
rate of breathing
what are acetylcholine and norepinephrine/noradrenaline used for
effecting autonomic activity, they bind to specific receptors to cause a response
which receptors do ACh bind to
muscarinic receptors
what receptors do norepinephrine and noradrenaline bind
adrenergic receptors
what primarily innervates vascular smooth muscle
the sympathetic nervous system through adrenergic receptors
what are the three types of adrenoceptors present in vascular smooth muscle cells
alpha 1 (a1)
alpha 2 (a2)
beta 2 (b2)
what is the main endogenous agonist of a1, a2 and b2
noradrenaline(NA)/norepinephrine(NE)
effect of binding at b1 receptor in the sinoatrial node & ventricles (sympathetic)
it increases heart rate and increases force of contraction in heart\
parasympathetic has opposite effect
effect of binding at a1 receptor in the arteries going to intestine and kidneys (sympathetic)
the vessels going to the intestine and kidneys are constricted
parasympathetic has opposite effect
effect of binding at b2 receptor in the skeletal muscle (sympathetic)
the muscle dilates
parasympathetic has opposite effect
effect of binding at b2 receptor in the lungs (sympathetic)
the airway in the lungs relaxes
parasympathetic has opposite effect
effect of binding at b2 receptor in the liver (sympathetic)
- glycogenesis happens (storage of glycogen)
- glucogenesis happens
(breakdown of glycogen to get glucose)
parasympathetic has opposite effect
effect of binding at b1 receptor in the kidneys (sympathetic)
increase in renin secretion
parasympathetic has opposite effect
what does the heart and smooth muscle found in the vasculature and airways always receive
dual innervation
(they are innervated to varying extents by both sympathetic and parasympathetic fibres)
what does inotropy mean
force of contraction
what does chronotropy mean
rate of contraction
what does dromotropy mean
rate of electrical conduction
example of drugs used for controlling blood pressure via actions on vasculature through sympathetic system
adrenoceptor blockers - alpha blockers
they work by preventing norepinephrine induced vasoconstriction
where are respiratory centres located
in the medulla and pons
what do the neurons in the respiratory centre do
they automatically send impulses to the muscle to contract and relax
which muscles do neurons in the respiratory centre send impulses to
the diaphragm via the phrenic nerve
the intercostal muscles via the intercostal nerves
what detects CO2 and O2 in the blood and changes the rate of breathing
sensors (chemoreceptors) in the brain, carotid artery and aorta
what does stimulation of parasympathetic nerve do in airways
- bronchial smooth muscle contraction
- increased mucus secretion
what does stimulation of the sympathetic division do in airways
- bronchial smooth muscle relaxation
- decreased mucus secretion mediated by b2 adrenoceptors
- increased mucocillary clearance mediated by b2 adrenoceptors
what do bronchodilators do
act to dilate the bronchi and bronchioles which increases airflow to the lungs
what do b2 agonists do (bronchodilators)
promote effects similar to what is seen with sympathetic stimulation
what do anticholinergics do (bronchodilators)
act to inhibit effects seen with parasympathetic system
