ANS Flashcards
What is the function of the reticular formation?
regulating the CV system, respiration and sleep-wake cycles. Also functions to filter incoming stimuli to discriminate irrelevant background stimuli
what is sinus arrhythmia?
When you inhale, your HR increases.
When you exhale, your HR decreases.
The more pronounced this phenomenon, the greater activity of vagal efferents to the heart
What effect does sympathetic stimulation have on the micturation process? What effect does parasympathetic stimulation have?
Sympathetic stimulation causes detrusor muscles to relax (via beta-2 adrenergic receptors) and sphincter muscles to contract (via alpha-1 adrenergic receptors).
Parasympathetic stimulation causes detrusor muscles to contract (via muscarinic receptors) and sphincter muscles to relax (via muscarinic receptors)
How will incontinence differ between a lesion in the peripheral nervous system and a lesion in the central nervous system?
peripheral nervous system - the detrusor muscle is flaccid because it lacks innervation. Thus, the detrusor muscle does not contract to empty the bladder, fills to capacity then overflows.
central nervous system - the detrusor muscle is spastic and so it contracts randomly and does not coordinate with the sphincters
What are some symptoms of autonomic dysfunction?
orthostatic hypotension, dry eyes or mouth, decreased sweating, constipation or diarrhea, early satiety or nausea after meals, sexual dysfunction, urinary inconsistency or hesitancy
What is one difference between Parkinson’s disease and multiple system atrophy?
MSA has early onset of autonomic dysfunction while PD has late onset of autonomic dysfunction
What parts of the brain influence the autonomic nervous system? What functions of the autonomic nervous system do they influence?
insular cortex - primary sensory and motor cortex for the ANS, relays through the hypothalamus
amygdala - regulates autonomic responses to emotions
anterior cingulate cortex - regulates autonomic responses related to goal oriented behavior
hypothalamus and pre optic area - integrate endocrine and autonomic responses
Nucleus of the solitary tract - relay for afferent neurons of the ANS
Nucleus ambiguus and dorsal motor nucleus of the vagus - motor
What is the pathway of the baroreceptor reflex arc (adjusting blood pressure after postural change)?
Afferent pathway: baroreceptors in heart and great vessels sense blood pressure; chemoreceptors in carotid body sense O2 and CO2 concentrations -> afferents of CN IX and X -> nucleus of the solitary tract
Efferent pathway: reduced parasympathetic stimulation of the heart, allowing the heart to beat at its naturally faster pace; sympathetic constriction of the blood vessels
What part of the ANS is responsible for sweating? What neurotransmitter do these neurons utilize?
The sympathetic system causes sweating and is one of the few cases where the postganglionic sympathetic nerve releases acetylcholine instead of epinephrine
