autonomic nervous systems Flashcards
homeostasis vs allostasis
internal set points vs homeostasis maintained during environmental changes (e.g. pregnancy)
position of ganglia (symp vs parasymp)
S: closer to CNS
P: closer to organs
spinal nerves for sympathetic
thoracic & lumbar
spinal nerves for parasympathetic
cranial & sacral
sympathoadrenal system
sympathetic preganglionic neurons innervate the ADRENAL MEDULLA
when activated, adrenal cells secrete A & NA -> widespread effects
sympathetic effects during major threat
inc HR, increase contraction of heart, inc. blood flow, decreased blood flow to gut, decreased gut motility
what nerves lie in pelvic plexus
sacral post-ganglionic
also contains many sympathetic fibres
parasympathetic action
decrease HR, decrease contraction of heart, increased gut motility
NTS
major integrative centre for ans function
caudal part of NTS receives sensory input about tissues and environment
hypothalamus
(inputs & function)
receives: sensory input, contextual information, hormonal signals
(central coordination of autonomic output via comparing situation to biological set point then adjusting).
spinal cord injury - primary issues
disruption between brain & organ connection
s.c. injury - secondary issues
nerve circuits damaged
organs start to change b/c unregulated
examples of s.c. damage problems
cardiovascular dysregulation, bladder & bowel problems, sexual dysfunction, disrupted thermoregulation
autonomic dysreflexia
s.c. injury at or above T6
acute hypertension triggered by bladder/ bowel dysreg, UTI, nociceptor activity
can lead to stroke, seizure & death
bladder dysfunction & s.c. injury
coordination between brain and organs control urethral sphincter to ensure opening is synchronised with bladder contraction
