ANS overview Flashcards
compare and contrast somatic and autonomic motor pathways
somatic:
- 1 neuron
- Ach only
autonomic
- 2 neurons
- Ach at ganglia
- Ach (parasympathetic) or NE/epi (sympathetic) at effector organs
parasympathetic NS projects from which regions
craniosacral
- CN 3, 7, 9, 10
sympathetic NS projects from which regions
thoracolumber
+ cervical ganglia projecting cranially
target organs of autonomic NS
smooth muscle
cardiac muscle
glands (endocrine and exocrine)
some adipose tissue
cervical ganglia
cervicothoracic ganglion
middle cervical ganglion
cranial cervical ganglion
prevertebral ganglia
celiac ganglion
cranial mesenteric ganglion
caudal mesenteric ganglion
sympathetic vs. parasympathetic synapse location
sympathetic:
ganglia closer to vertebrae than effector organ (or the adrenal gland)
parasympathetic:
pre-ganglionic neurons synapse with terminal ganglia much closer to the effector organ(s)
function of limbic system
PRESERVATION OF SELF AND SPECIES
- motivation
- reinforcement of positive survival behaviors
- sets level of arousal
- regulates hormone secretion
- regulates autonomic function (esp. cortisol)
limbic input
amygdala
hippocampus
limbic cortex
limbic output
primarily hypothalamus
septal nuclei
autonomic control of hindbrain
- micturition (urination) centers
- respiratory centers
- vasomotor and vasodilator control centers
compare and contrast autonomic outflow from different brain regions
brainstem
- autonomic control centers: urination, respiration, and blood pressure
hypothalamus
- descending control of thirst, appetite, temp. regulation, osmolarity, and visceral function
limbic system
- descending control of autonomic outflow associated with emotional stimuli
hypothalamus structure
ventral half of the diencephalon
around/beneath the third ventricle and beneath the thalamus
composed of several small nuclei
connected (in function and structure) to the pituitary gland
hypothalamus function
HOMEOSTASIS
- endocrine function
- behavior
- autonomic control
- sexual function
- circadian cycles (suprachiasmatic nucleus)
primary input to hypothalamus
brainstem
limbic system (esp. hippocampus and amygdala)
eyesight
primary output from the hypothalamus
spinal cord
thalamus
pituitary
pineal
vagal motor nuclei
5 “key concepts” regard the hypothalamus
- principle diencephalic component of the ANS
- receives input from the periphery and higher brain centers
- linked to the pituitary
- linked to the reticular formation and spinal cord
- integrates mechanisms of homeostasis
