Autonomic nervous system Flashcards
What makes up the sympathetic trunk?
(Spinal cord – thoracic and lumbar nerve pathway making contact with ganglia known as sympathetic trunk)
What does the parasympathetic nervous system do?
- organ specific control (Eyes, mouth, lungs, heart, bladder, intestines
- Eg. Cranial nerve 10 supplying sympathetic control to most of viscera (organs in chest region)
What does the parasympathetic nervous do?
Rest and Digest
- Craniosacral
- Myelinated preganglionic Long fibres and nerve pathways (more quick action potential) and short non-myelinated postganglionic fibres or nerve pathways
-** Releases acetylcholine at synapses **
What does the sympathtic nervous system do?
**Flight and fight **
- Two sympathetic trunks on either side of spinal cord associated with sympathetic ganglion
- AP along major spinal nerve (in grey ramus) out then nerve fibre passes through **white ramous **entering sympathetic trunk and sympathetic ganglion
- Gray ramus neurones control blood vessels, sweat glands and hair follicles
- Some branch out from white ramus along prevertebral ganglion to the viscera (organs in abdomen)
- Then others go to organs in chest
- Relatively short lightly myelinated preganglionic axons
- acetylcholine at synapse then short non-myelinated postganglionic axon and release nor epinerorine (nor adrenaline) onto effector organs
What is the paravertebral ganglia?
Ganglia of sympathetic trunk
Send branches to pre vertebral ganglia which controls organs of the abdomen
WHats the prevertebral ganglia?
preaortic ganglia
Called solar plexus (winding is when this is put under pressure)
- Celiac ganglia - stomach and liver
- Superior mesenteric ganglia – colon and small intestine
- Aortorenal ganglia – renal system of kidneys
- Inferior mesenteric ganglia – colon and rectum
What adrenal glands are in the kidneys?
medualla and cortex
What does the medulla gland do in kidney?
- contain chromaffin cells which are modified neurone releasing **epinephrine and nor epinephrine (adrenaline) **–
- attached to sympathetic nervous system by celiac ganglion into adrenal medulla
What does the cortex gland do in the kidney?
- producing of stress hormone cortisol also promoting glycogenesis in liver, liberation of nutrients, glucose and proteins and promotes gluconate
- rich blood supply
What is a neurohemal organ?
Chromatin cells release epinephrine or nor epinephrine directing into the blood
Whats the process of the parasympathetic nervous system?
rest and digest
Body recovery and resupply of tissues with nutrients
- **Broncho constriction **of lungs (less blood circulation and ventilation of lungs)
- **pupils constrict **– focusing on short/ close vision
- Increased salvation – watery - getting ready to eat
- Gastrointestinal tract – activated to secrete acid and digestive juices – preparing to eat
What happens when the sympathtic nervous system is activated?
- Heart – rate increase, stroke volume increased
- Blood flow redistributed – increased to skeletal muscle and cardiac blood vessels
- Broncho dilation – more oxygen needed with more ventilation
- **Salivary glands – activated – viscous **thick saliva – to protect delicate membranes in mouth
- Pilo erection – hair stand on end – contracting pili cells
- Pupils of eyes dilate – focus further away
- **Liver – glucogenesis in liver releases glucose **form liver – increasing respiration
- **Releasing fatty acids **from white fat of the body
Whats the distribution differences of the sympathetic and parasympathtic nervous system?
- Not all tissues have symp and parasym nerve system
- Hair follicles – only sympathetic
- Blood vessels mainly sympathetic
- Sweat and adipose only sympathetic
- Iris only parasympethic
How does brain stem change in autonomic control?
Reticular formation:
- Cardiac fazers and respiratory centres
- Those areas responsible for blood pressure, circulation, blood flow and salivation change due to activation of sympathetic nervous system
What the 4 nuclei involves in brain stem control of cardiac output?
- solitary nucleus
- sepressory area
- nucleus ambiguous
- pressor are
How does the solitary nucleus control cardiac output?
**- sensory input zones with **baro receptors **and input
- pressure sensers and chemoreceptors
- pH of blood and blood gases – links to 2 and 3
What doe depressor areas do to control cardiac output?
- inhibition of sympathetic nervous system
- when activated inhibits sympathetic tone in pressor area
How does the nucleus ambiguoud control cardiac output?
- controls vagus nerve
- in response to changed blood pressure
- changing cardiac output and regulation of blood
How does the pressor area control cardiac output?
– sympathetic area activated by depressor area
What are three main nuclei involbes in brain stem control of respiratory function?
- ventral respiratory group
- dorsal respiratory group
- pontine nuclei
also solidary nucleus
How does the ventral respiratory group control repsiratory function?
- central pattern generator
- two sets of brain cells pattern of inspiration and exploration complimentary
How does the dorsal respiratory group control repsiratory function?
- info from **solitary nucleus **as well as lots of information from receptors where ventral respiratory group is controlled due to stimuli
How does the pontine nuclei control repsiratory function?
higher level of control than dorsal as regulates relationship between nuclei smoothing motor activity
What does the vagus nerve do in autonomic control?
- 90% parasympathetic NS go through area
-** Input of sensory** (stretch and chemoreception) info from lungs, bladder, circulatory system and digestive tract - Adjustments made via autonomic nervous effectors
What does hypothalamic control mean?
- ‘boss’ with overall integration of controlling SNS and PNS in ANS
- Autonomic sensory inputs into hypothalamus by visual stretch receptors of vagus nerves – temp, HR, pH, CO2 levels, osmilary system
- Regulatory zone
WHat does the cerebral cortex do?
- Frontal lobe
- Cognitive stressor
- To control hypothalamus and limbic system due to psychosocial output
What does the limbic system do?
- Emotional input – eg. Comfort eating, reproduction. – scared
- Emotional input of sensory experiences
