Autonomic Nervous System Flashcards
(26 cards)
what does the ANS control
involuntary actions - smooth muscle, cardiac muscle and various glands
what are the 2 divisions of the ANS
sympathetic NS, parasympathetic NS
where are the cell bodies or pre-ganglionic neurons in the parasympathetic division?
CN 3,7,9 (head structures) , CN 10 (thoracic and abdominal organs), S2,3,4, (perlvic organs)
where are the cell bodies of the pre-ganglionic neurons in the sympathetic divison?
thoracic and lumbar regions of the spinal cord T1-L2
what is the structure and organisation of the neurons in the parasympathetic nervous system?
long pre-gang neuron, short post-gang neuron, ganglion near or in effector organ
what is the structure and organisation of the neurons in the sympathetic nervous system
pre- and post- gang neurons similar in length, synapse in sympathetic chain or one of the collateral (or pre-vertebral) ganglia or in the adrenal medulla
what is the functions of the parasympathetic nervous system?
discrete actions on single organs in the body core (salivary gland, heart) and conservative anabolic effects (storing energy, digestion, slowing heart)
what is the general function of the sympathetic nervous system?
more widespread actions often affecting the whole body
what are the functions of the sympathetic nervous system?
distribution of sympathetic nerves, circulating adrenaline, homeostasis (blood pressure, thermoregulation) , fight flight or fright (meeting demands of active muscle and anxiety)
what system is the adrenal medulla part of?
the sympathetic nervous system
what parts of the body does the ANS effect?
smooth muscle (blood vessels in various parts of the body, bronchi and bronchioles) , heart (gastro-intestinal tract, rate and force of contraction) , glands (salivary glands, gastro-intestinal glands and sweat glands) , metabolism
what does the ANS not control?
breathing
what does (nor)adrenaline cause?
contraction of smooth muscle in blood vessels (vaso-constriction) and relaxation of bronchial smooth muscle (bronchodilation)
what does the alpha ANS receptor do?
contraction of smooth muscle
what does the beta ANS receptors do?
relaxation of smooth muscle, increase heart rate and force of heart contraction, beta-blockers, block beta-1 receptors only so their effects are restricted to the heart
what is adrenaline commonly used as?
a vasoconstrictor
what are the cholinergic receptors?
muscarinic receptor and nicotinic receptors
what are adrenergic receptors
alpha and beta receptors
where are muscarinic receptors
post-gang, neuro effector junctions and blocked by atropine
where are nicotinic receptors?
pre-gang and post-gang neuron synpases and neuromuscular junctions
what structures receive sympathetic and parasympathetic nerves
many organs in head, thorax, abdomen and pelvis
how is control established between parasympathetic and sympathetic nerves
balancing their activity
what nerve supply do blood vessels and glands in the periphery receive?
sympathetic only
in relation to heart rate what does the parasympathetic nerves do?
decrease heart rate
