structure of ANS 1 Flashcards
where do preganglionic sympathetic neurons originate?
the thoracocolumbar region of the spinal cord
where do preganglionic neurons of the parasympathetic nervous system originate?
craniosacral region of spinal cord (usually brainstem)
where do postganglionic sympathetic neurons come from?
IN GANGLIA which come from the paravertebral chain or the pre vertebral chain
where do postganglionic parasympathetic neurons come from?
FROM Ganglia which originate in or near the target organ
which autonomic nervous system has short preganglionic fibres and long postganglionic fibres?
sympathetic
which autonomic nervous system has long preganglionic fibres and short post ganglionic fibres?
parasympathetic
what route do preganglionic SYMPATHETIC neurones take from the CNS to reach structures in the head (e.g. dilator muscle of iris)
leave the CNS, travel up in the parasympathetic chain and synapse on a higher up ganglia.
what route do preganglionic SYMPATHETIC neurones take from the CNS to reach structures in the body wall (e.g. sweat glands etc)
leave the CNS and synapses on a postganglionic neurone at a ganglia at the same level
what route do preganglionic SYMPATHETIC neurones take from the CNS to reach structures of the lower limb?
leaves the CNS, travels down in the paravertebral chain and synapses on a ganglia further down
what route do preganglionic SYMPATHETIC neurones take from the CNS to reach viscera of abdominopelvic cavity (e.g. stomach and intestines)
leave the CNS, synapse in pre vertebral chain.
which sympathetic pre vertebral ganglia supplies the liver, spleen, stomach, small intestine, proximal colon, kidneys?
the celiac ganglion
which sympathetic pre vertebral ganglia supplies the distal colon?
superior mesenteric ganglion
which sympathetic pre vertebral ganglia supplies the rectum, urinary bladder and genitalia?
inferior mesenteric ganglion
what is the effect of the parasympathetic nervous system on the heart?
decreases heart rate (RATE ONLY)
wha is the effect of the sympathetic Nervous system on the heart?
increases it (increases heart RATE and force of contraction too)
what is the effect of the parasympathetic nervous system on the digestive tract?
increases motility and secretion
what is the effect of the sympathetic nervous system on the digestive system?
decreases motility and secretion
what is the effect of the parasympathetic nervous system on the lungs?
bronchoconstriction
what is the effect of the sympathetic nervous system on the lungs?
bronchodilation
what is the effect of the parasympathetic nervous system on the bladder?
release of urine (constriction of visceral detrusor muscles and relaxation of sphincter muscles)
what is the effect of the sympathetic nervous system on the bladder?
urinary retention (relaxation of visceral smooth muscle and constriction of sphincter muscles)
what is the effect of the parasympathetic nervous system on the pupil?
constricts (miosis)
what is the effect of the sympathetic nervous system on the pupil?
dilates (mydriasis)
what is the effect of the parasympathetic nervous system on the male sexual organs?
erection
what is the effect of the sympathetic nervous system on the male sexual organs?
ejaculation
what is the effect of the parasympathetic nervous system on blood vessels?
mostly no effect
what is the effect of the sympathetic nervous system on the blood vessels?
constriction mostly - increases Bp and HR
what is the effect of the parasympathetic and sympathetic nervous systems on the salivary glands?
both increase secretion
what is the effect of the parasympathetic nervous system on the sweat glands?
no effect
what s the effect off the sympathetic nervous system on the sweat glands?
increase secretion
what is the effect of the parasympathetic nervous system on the liver?
no effect
what is the effect of the sympathetic nervous system on the liver?
glycogenolysis and gluconeogenesis
what is the effect of the parasympathetic nervous system on the pilomotor?
no effect
what is the effect of the sympathetic nervous system on pilomotor?
piloerection
what effects does the sympathetic nervous system have on the two muscles of the bladder when the bladder is FILLING?
relaxation of detrusor muscles
contraction of internal sphincter muscles
what effect does the parasympathetic nervous system have on the two muscles of the bladder when the bladder is fun (to empty it)?
constriction if detrusor muscles and relaxation of internal spinster muscles
how does sympathetic innervation of the adrenal medulla cause the release of adrenaline (80%) and noradrenaline (20%)?
preganglionic fibres synapses diresti onto chromatin cells of the adrenal medulla
what neurotransmitter do all preganglionic nerurons in the sympathetic and parasympathetic systems release into the ganglia?
ACh
what type of receptors are present in the postganglionic neurons in the ganglia of sympathetic and parasympathetic systems?
nicotinic receptors
what neurotransmitter do ALL postganglionic parasympathetic neurons realease?
ACh
what neurotransmitter do MOST postganglionic sympathetic neurons release?
noradrenaline
which is the only target organ of the sympathetic nervous system are stimulated by ACh on muscarinic receptors?
sweat glands
