anatomy of the ANS interactive lecture Flashcards
purpose of the ANS
maintain homeostasis
invol control of the viscera and glands
influence respiration, digestion, excretion, thermoregulation, cardiovascular activity
3 divisions of ANS
SNS
PNS
enteric
how many neurons are there in the SNS pathway from the CNS to the target organ
2 - preganglionic and postganglionic
what is the high level of control of the autonomic nervous system
hypothalamus
part of the limbic system
responds to changes in the internal and external environments
causes changes I the medulla that affect the SNS and PNS
where are the ganglia in the SNS
sympathetic chain - paravertebral ganglia
except the splanchnic nerves - they just pass through the sympathetic chain and synapse in the paravertebral ganglia
no synapse for the adrenal gland innervation - suprarenal`
describe the thoracolumbar outflow
preganglionic fibres of SNS emerge from T1-12 and L1-2/3 segments as spinal nerves
where does the SNS innervate
eye
glands and mucous membranes in head and neck
thoracic, abdominal and pelvic viscera (internal organs )
Bv
sweat glands
erector pili
where do the PNS nerves synapse
close or in the target organ /viscera
the head and neck ganglia are: ciliary, pterygopalatine, submandibular, otic
describe craniosacral outflow
preganglionic nerve fibres of PNS emerge as cranial nerves and sacral spinal nerves S2-4
cranial nerves associated with the PNS
3 oculomotor (ciliary ganglia), 7 pterygopalatine (submandibular ganglia), 9 Glossopharyngeal (otic), 10 vagus
what does the PNS innervate
eye
glands and mucous membrane of the head and neck
thoracic, abdominal and pelvic viscera
NOT adrenal (suprarenal) bv, sweat gland or erector pili
why do the places that the SNS and PNS innervate differ
SNS - mass response, mobilise body energy for increased activity - urgency
PNS - discrete, localised, conserves body energy
describe the lateral horn of the spinal cord
where the preganglionic cell bodies are - emergence of cell bodies from the spinal cord
T1-L2/3 SNS innervation
S2-S4 PNS innervation
axons pass through ventral root to spinal nerve
describe rami communicantes
connect spinal nerve to the sympathetic chain
white rami at lateral, contains the preganglionic axon of the sympathetic neuron
grey ramus communicans - sympathetic postganglionic axons to bv, sweat glands and erector pili
describe the ciliary ganglion
PNS - close to the target organ
cranial nerve III - oculomotor
constrict pupil and ciliary eye muscle - accommodation
