Exam 1: Autonomic Nervous System Flashcards
Autonomic nervous system
involuntary
visceral subdivision
integrated with endocrine system
gets input from hypothalamus and cerebellum
divisions of ANS
sympathetic: response to stressors
parasympathetic: controls homeostatic responses at rest
things involved in parasympathetic division
- constricted pupils
- stimulate saliva
- constrict bronchi-brings to relaxed state
- dec HR
- GI tract - relaxed to digest food
- stimulates urination
things involved in sympathetic division
- dilate pupils - more alert, focused
- inhibit saliva production
- dilate bronchi - more airflow for running and flighting
- inc HR
- adrenal gland for epinephrine and norepinephrine
- glucose release
- inhibits stomach, intestines, pancreas - some gastric upset
- inhibits urination - sometimes pee bc of pressure out on bladder if full
Nerves in ANS
- always 2 neurons
preganglionic neuron comes in myelinated, quick, all using Ach
postganglionic neuron not myelinated, slower
if postganglionic and parasympathetic - what neurotransmitter
what about sympathetic??
parasympathetic: acetylcholine
sympathetic: norepinephrine
what is the sympathetic division known as and why?
thoracolumbar
preganglionic cell bodies are located in the lateral horn of T1-L2
3 types of ganglia in thoracolumbar division
chain
collateral
suprarenal
paired ganglia that are located near and run parallel to the vertebrae
control body wall, limbs, and viscera ABOVE the diaphragm
NOT innervated by cervical nerves
chain ganglia
stellate ganglion
most
ones that stay inferior combined with T1
control viscera BELOW diaphragm
preganglionic neurons pass through chain without synapsing
celiac, superior mesenteric, inferior mesenteric
travel down from thoracic and go out
collateral ganglia
central region of the adrenal gland, midline
modified sympathetic nervous tissue
preganglionic neuron passes through chain without synapsing
suprarenal ganglia
celiac collateral ganglia
T5-T9 forms greater splanchnic nerve that supplies ganglia
innervates: stomach, liver, gallbladder, spleen, pancreas (not beta cells)
pass through for suprarenal
splanchnic
viscera
superior mesenteric collateral ganglia
T10-T11 forming lesser splanchnic nerve that supplies ganglia
innervates: small intestine and initial part of large intestine
inferior mesenteric collateral ganglia
T12-L2 forms lumbar splanchnic nerve that supplies ganglia
innervates: rest of large intestine, rectum, kidneys
bladder and sex organs (but crossover) - little chain sacral splanchnic
-sacral-sympathetic
pelvic-parasympathetic
what does the preganglionic neuron communicate with
sympathetic trunk
what is the parasympathetic division also known as and why?
craniosacral
preganglionic cell bodies part of 4 cranial nerves (oculomotor, facial, glossopharyngeal, and vagus)
oculomotor
cranial nerve 3
- intrinsic eye movements, iris constriction, most extrinsic not superior oblique(trochlear) or lateral rectus (abducens)
facial nerve
cranial nerve 7
- salivation
glossopharyngeal
cranial nerve9
salivation
vagus nerve
branch to sensory function of ear in eardrum
cranial nerve 10
goes to heart, bronchi, digestive system
pelvic splanchnic
parasympathetic
most urogenital
visceral
2 types of ganglia in craniosacral
no chain ganglia!!
terminal and intramural
terminal vs intramural ganglia
terminal: synapse near, but outside of target organ
intramural: synapses IN the target organ - synapses with postganglionic neuron
4 types of terminal ganglia
ciliary
pterygopalantine
submandibular
otic
innervated by fiber tracts from the oculomotor nerve for intrinsic eye movement
these bodies are in the eye neopoint accommodation
ciliary terminal ganglia
innervated by a branch of the facial nerve for lacrimal and nasal mucosa secretions
pterygopalantine terminal ganglia
innervated by a branch of the facial nerve for sublingual and submandibular gland secretions
salivation
submandibular terminal ganglia
innervated by fibers from the glossopharyngeal nerve for parotid gland secretions
largest salivary gland
otic terminal ganglia
the majority of parasympathetic ganglia are _____
intramural ganglia
where does the vagus nerve provide innervation to
organs of thorax and viscera in the abdomen
what innervation is carried out by ganglia of the sacral region?
lower portion of colon, rectum, urogenital
autonomic nerve plexuses are involved in_____
dual innervation of an organ with both sympathetic and parasympathetic divisions - work together
what are the 8 autonomic nerve plexuses and which are above the diaphragm?
cardiac, pulmonary, esophageal (above diaphragm)
celiac/solar plexus superior plexus inferior mesenteric renal hypogastric
cardiac plexus
Parasympathetic fibers: of vagus nerve, dec HR, coronary vessels constrict, relaxed diameter
Sympathetic fibers: from T1-T4 (T5) - inc rate and force , inc diameter of coronary blood vessels - more strength in action potential
where is the cardiac plexus?
- 2 interconnected regions : superficial and deep
left side of heart gives superficial, right side is deep between heart and trachea
How can the heart get more blood flow not controlled by the plexus?
- if not enough O2 the heart releases adenosine
- relaxes blood vessels, local arterioles
- arterioles relax to get more blood flow
if hypoxic situation the heart puts this out as emergency signal - should work unless you have a blocked artery
pulmonary plexus
parasympathetic fibers: of vagus: constrict the bronchi
sympathetic fibers: from T1-T4: dilate bronchi
heart rate inc and dilate bronchi (lungs and heart interconnected)
plexus goes laterally around each bronchi - sensory and motor fibers
between cardiac and esophageal plexuses
esophageal plexus
parasympathetic fibers: of vagus: produce rhythmic peristaltic contractions
sympathetic fibers: T1-T4: constriction of esophageal lower sphincter, inhibition of peristalsis
left vagus anterior, right posterior
heart burn vs heart attack
acid reflux or esophageal spasms get confused between heartburn and heart attack
- acid reflux can cause pain up into arms and neck which ppl may think is heart attack and is not or opposite and it is and they do not think it is
- belching relieves heart burn but not a heart attack
celiac plexus
parasympathetic: mainly vagus nerve, some splanchnic
- stimulate digestion
sympathetic: celiac and superior mesenteric ganglia
- inhibit digestion
largest plexus behind the stomach and in front of abdominal aorta
has branches to all abdominal viscera
superior mesenteric plexus
parasympathetic: right vagus
- stimulates digestion
sympathetic: superior mesenteric ganglion
- inhibits digestion
continuation of celiac plexus, in front of abdominal aorta at superior mesenteric artery
all external forces on digestive system
can accelerate or decelerate nervous system of the digestive system
plexus
inferior mesenteric plexus
parasympathetic: pelvic splanchnic nerves
- stimulate defecation
sympathetic: lumbar/sacral splanchnic nerves
- inhibit defecation
renal plexus
parasympathetic: from celiac ganglion
- dilation of renal artery to kidneys
Sympathetic: from splanchnic nerves (T10-L2)
- constriction of renal artery (raises BP)
hypogastric plexus
superior and inferior - each side there is an inferior that are linked
parasympathetic: pelvic splanchnics
- urinary branches stimulate urination
- reproductive branches increase blood flow to organs
sympathetic: lumbar splanchnic in origin but come out as sacral
- urinary branches inhibit urination
- reproductive branches stimulate muscle contractions
mainly controlled through hormones
visceral reflexes can be ______
long or short
reflex involving interneurons of the CNS
long visceral reflex
reflex that bypasses the CNS and synapses in ganglia
- get response back from the ganglia (motor response)
short visceral reflex
example of a short reflex
enteric plexus
- acts independently to control digestion and includes all nerves from the esophagus to anus
- can have someone with spinal cord injury but can still breathe and have a functioning digestive system
- enteric plexus is independent nervous ssytem of digestive system
sympathovagal balance
when changing position, accommodation has to be made so brain continues to receive sufficient amount of blood
- parasympathetic to sympathetic conversion
why do these conditions cause an imbalance and result in fainting?
-dehydration, atherosclerosis, vasovagal syncope
dehydration: loss of volume - not be able to constrict enough
atheroclerosis: blood will not be able to get through dur to the plaque
vasovagal syncope: no reason for the big sympathetic response, you just drop - dec HR, dec BP
