Homeostasis and the autonomic nervous system L1 Flashcards
homeostasis
function integration of different organ systems for variable maintenance within a limited range in order to control internal environment
homeostasis mechanism stages
stimuli
sensor
controller
effector
response
negative feedback of retina
ganglia in retina detect ambient light/output via ANS for iris muscle adaptation
iris muscle adaptation muscle and effects
constrictor> sphincter pupillae circular
radial> dilator pupillae
control centres of ANS
hypothalamus
brain stem
spinal chord
efferent pathways and relationship
parasympathetic and sympathetic
(antagonistic unconscious control)
preganglionic origin
in CNS
Can synapse w many postganglionic neurones
postganglionic origin
in autonomic ganglia
hormones involved in fight or flight response
noradrenaline
adrenaline
osteocalcin
cortisol
fight or flight mechanism stages
stimuli> amygdala centre > bone osteoblasts > osteocalcin > inhibits parasympathetic neurones
preganglionic origin neurones para
cranial nerve
pelvic nerve > rectum/ bladder
(long!)
postganglionic origin para
on/ near target organ
(short!)
sympathetic
preganglionic origin
postganglionic origin
thoracic
2 paravertebral symp chains
adrenal medulla location and function
innervated by sympathetic preganglionic neurones
secretes adrenaline / noradrenaline into bloodstream
ANS neurotransmitters
ACh
noradrenaline
adrenaline
non adrenergic/ cholinergic neurotransmitters
