What is the purpose of the autonomic nervous system (basic)?
- regulate homeostasis and reproduction
- a lot of the functions are reflexive
What are the 3 components of the autonomic nervous system and their main function?
- Enteric system: innervates gut
- Sympathetic: fight or flight
- Parasympathetic: more discrete- relaxes the body
All systems within the ANS have ________ and ___________ components.
- GVE: general visceral efferent (motor)
- GVA: general visceral afferent (sensory)
What is afferent information transmitted through before taking efferent pathways to the parasympathetic and sympathetic systems?
limbic system <---> hypothalamus <---> reticular formation <---> spinal level
Name differences between the skeletal muscle and the smooth muscle:
- MAIN DIFFERENCE: in skeletal muscle a single motor neuron travel out and innervates skeletal muscle, whereas in smooth muscle (autonomic) have 2 motor neuronal chain- preganglionic and postganglionic
- autonomic functions are usually unconscious and influenced by hormones
Name five ways the SNS is different from the PSNS (only SNS characteristics):
- activate the body (fight or flight)
- preganglion arise from thoracolumbar (T1-L2) lateral gray horn
- short preganglionic/long postganglionic
- global responses
- main postganglionic NT= norepinephrine (except Ach in sweat glands)
Name 5 ways the PSNS is different from the SNS (only PSNS characteristics):
- prepare body for restpreganglion arise from CN III, VII, IX, X & S2, S3, S4
- long preganglion/short postganglion
- discrete, local responses
- postgangionic NT= acetylcholine
What are the 4 main similarities between the SNS and the PSNS?
- the nucleus is in the spinal cord or brainstem
- preganglionic neuron is B fiber which is equivalent to A-Delta (small, myelinated)
- postganglionic neuron is C fiber (small, unmyelinated)
- Ach is NT of preganglionic in PSNS and SNS
What is the neurotransmitter at the postganglionic neuron that travels to the heart and blood vessels?
norepinephrine (adregenic receptor)
What type of receptor is at Ach released on at sweat glands?
What do the cells of the adrenal gland act as in one of the sympathetic neuronal chains and what do they release?
They serve as the postganglionic neuron releasing epinephrine directly into blood vessels
Where are the cells of the peripheral ganglia derived from in the SNS? (the adrenal gland cells are derived from these as well)
neural crest cells
Describe the neuronal chain for the parasympathetic nervous system (receptor type and where):
- preganglionic neuron releases Ach on the postganglionic neuron that also releases Ach
- muscarinic receptor
- smooth muscles, glands, heart
What is the effects of the neurotransmitter depend on?
it depends on the receptor type activated by the neurotransmitter
What are the two types of cholinergic receptors?
- Nicotinic Receptors
- Muscarinic Receptors: regulate glands, smooth muscles, heart
Does binding of Ach at nicotinic recepetors cause a fast IPSP, EPSP or both and where does it occur?
- fast EPSP
- on post ganglionic membrane
Does binding of Ach at muscarinic receptors cause an EPSP, IPSP, or both and where does it occur?
- both IPSP and EPSP
- activates only receptors on the effector membrane
What do cholinergic receptors secrete?
What do Adrenergic receptors secrete?
What are the two groups of adrenergic receptors?
- alpha and beta
- alpha 1 and 2
- beta 1 and 2
What do the adrenergic receptors alpha 1 and alpha 2 cause?
What does the adrenergic receptor beta 1 cause?
decrease HR and contractility (beta blockers would block these sites)
What does the adrenergic receptor beta 2 cause and when would it be useful
- respiratory dialation
- treat asthma
What are the main functions of the Sympathetic Nervous System?
- increase HR
- increase sweating
- dilates pupils
- inhibits GI movement
- close sphinctor
- diverts blood from skin
- GI tract to skeletal muscle
i still need to figure this slide out....
What are the main functions of the Parasympathetic Nervous System?
- promote digestion
- GI perstalsis
- slows HR
- constricts pupil
- empties bladder
- relaxes sphinctor
- mediates genital erection
Where does cranial nerve III arise from and terminate?
arise from Edinger-Westphal and goes out to ciliary ganglion and terminates on post ganglion that innervates pupil constrictors
Where does cranial nerve VII arise from and terminate?
arise from superior salivatory nuclei and travel out to sphenopalantine and submandibular, innervating the lacrimal and submandibular gland
Where does cranial nerve IX arise from and terminate?
arise from inferior salivatory nuclei and innervates otic ganglia and postganglion travel to parotid gland
Where does cranial nerve X arise from and terminate?
arise from upper portion of medulla and preganglion travel down to thoracic and upper 2/3 abdominal viscera and provide parasympathetic input to these regions. lower portion abdominal receives parasympathetic from S2-S4
Where does the heart refer pain to?
- That's why in men they report left arm weakness with a heart attach because it shares sensory infor from T1
What does T6-T8 have referred pain to?
Where does the stomach refer pain to?
Where does the superior cervical send sympathetic output to?
What is considered the "stellate" ganglion?
the fusion of the inferior cervical ganglion and T1
Where do the middle cervical ganglia and inferior cervical ganglia send sympathetic output to?
What is under descending control of the hypothalamus?
Cranial nerve III, VII, IX, X
What is the basic problem with Horner's Syndrome?
sympathetic input to the face has been disrupted
Where has damage occured to cause Horner's Syndrome?
- descending fibers from the hypothalamus that go down to upper thoracis SC levels
- superior cervical ganglia where the postganglion arise to travel to the face
What are possible causes of the damage that has occured to causes Horner's Syndrome?
- brainstem stroke (damage descending pathways)
- SCI (damage descending pathways)
- wound, infection, or superior lobe resection of the lung (famage peripheral ganglia)
What are four common characteristics of Horner's Syndrome?
- miosis: paillary constriction
- anhidrosis: lack of sweating on one side of face
- ptosis: drooping of the eyelid
- enophthalamos: eyes sinks into the orbit
What is the external sphinctor of the bladder controlled by?
skeletal muscle (voluntary control)
What are the basic SNS and PSNS functions of the bladder?
- SNS: retention
- PSNS: bladder
Where does the internal sphinctor receive input from?
Sensory input in the wall of the bladder helps do what?
Form the reflexive arc with the external sphinctor so it closes off, and doesn't stretch too much
Where is the PSNS input from in the bladder?
S2-S4 (detrusor mm)
Where does ascending input from the bladder travel?
cortex and brainstem
What nerve roots correspond with incontinence?
S2, S3, S4
What does the descending output "tell" the bladder?
that's it's okay to "go"
What is another name for spastic bladder?
- automatic reflex bladder
What happens in a spastic bladder and where has the injury occurred?
- injury occurs to SC or CNS above S2
- as bladder fills it continually stretches causing a reflex contraction of detrusor
What is another name for atonic bladder?
What happens with a flaccid bladder
LMN is intact by there is no descending control the stretch reflex is blocked allowing the bladder to continue to stretch and it eventually starts leaking out
What causes autonomic dysreflexia (big picture)?
noxious stimuli occurs below the lesion which fires up the SNS becauses there are now descending pathways to counteract it
What are two red flags that someone may have autonomic dysreflexia?
- increase in perspiration
What's a common cause of autonomic dysreflexia?
kink in a catheter so the pressure builds up in the bladder because it can't get rid of the urine which arouses the SNS
What happens in autonomic dysreflexia (BP, HR, etc....)
- CO increases causing vasoconstriction and an increase in BP
- increase in BP stimulates the vasculature receptors, which increase the PSNS activity which causes a vagal response to decrease HR and vasodialtion above level of the lesion
- SNS and PNS compete --> could cause death