9/20b Integrating Autonomic & Volitional Control (Biomedical Sciences) Flashcards
• Basics of neuro • How systems function together • Divisions • Neural circuits • Neurotransmitters • How ANS helps in maintaining function • What happens when people have dysfunction
Global Nervous System
- Brain, cerebellum, spinal cord
- Forebrain (cerebral cortex, basal ganglia, white matter)
- Diancephalon (deep inside cerebrum)
- Thalamus
- Brainstem (midbrain, pons, medulla)
- Spinal cord (cross sectional area smaller than a penny, caude equina)
Autonomic NS divisions***
primarily communicates with internal organs and determines their function
- sympathetic NS: has to go through a stressful/challenging situation. Increases arousal and expending energy, fight or flight
- Parasympathetic NS: maintain normal HR, breathing, allows you to relax and conserve energy, rest and digest
- Enteric**: works closely with ANS, but doesn’t rely on them, responds to SNS and PNS
when is diastolic pressure higher?
hardened artery
Decondititoned patients with orthostatic hypotension
bedridden, brain or spinal cord injuries, not a lot of time in upright sitting, complain of sweating and feeling flushed, light headedness and palor
Big picture of ANS
- need to get patients back into ADL we need muscles, heart, respiratory system, energy systems
- all of the above are controlled by nervous system
Somatic NS and CNS
control muscles
autonomic NS and CNS
cardio-respiratory system and ATP system in the body that controls metabolism
Functions and effects of PNS and SNS on different organs
almost all of the organs are not under your direct volitional control
–we don’t have full volitional control over our heart rate, or adrenal medulla
ANS Neural Circuitry
all organs involuntary functions receive inputs from SNS and PNS and can be done in 2 ways:
- Reduce SNS flow and increase PNS flow
- Increase SNS flow and decrease PNS flow
what section of the spinal cord does the SNS innervation come from?
thoracolumbar outflow section of the spinal cord: t1-l2/3
- exit spinal cord and supply/synapse pre/para vertebral chain of ganglia
- Axons of the neurons form ganglia exit and supply organs
what section of the spinal cord does the PNS innervation come from?
brainstem nuclei and sacral section of your spinal cord (craniosacral outflow - brasinstem nuclei are in the sacrum): S2-S4
- neurons send axons to parasympathetic ganglia where there is another neuron
- neuron from the parasympathetic ganglia exits ang goes to the organs
Somatic motor system vs autonomic motor system
Efferent Somatic - skeletal muscle and a neuron sitting in spinal cord (anterior horn cell) axons come out from the ventral root
Efferent autonomic - neuron in CNS (pre-ganglion), exits CNS, synapses on the autonomic ganglion (post ganglion neurons) then the axons (post ganglionic fibers) of the ganglion supply the organ
Location of the Pre ganglionic neuron in SNS/PNS
sits in the spinal cord
Location of the Post-ganglion neuron in SNS/PNS
sitting in either the pre or paravertebral chains
Preganglionic neurons release what?
in SNS and PNS always secrete Ach as neurotransmitters. Axons of the pregang are the Post ganglion nerves and produce effects on the end organ
what are the horns of the grey matter?
- posterior
- anterior: axons of the pregang neurons leave from the anterior/ventral roots and supply/innervate the autonomic ganglia (in pre or paravertebral chains)
- lateral: pregang neurons are in the lateral horn