PNS Flashcards
Peripheral Nervous System
transmits signals between the CNS and the rest of the body
Autonomic Nervous System
- A division of the peripheral nervous system that controls involuntary responses by influencing organs, glands, and smooth muscle.
Sympathetic Division
-Division of the ANS that prepares the body for stressful energetic activity fight or flight
Parasympathetic Division
- Division of the ANS that dominates during times of rest and relaxation and directs Maintenace activities
Sympathetic division has what receptors
Adrenergic - Alpha and beta
Parasympathetic has what receptors
Cholinergic- muscarinic and nicotinic
Synaptic Transmission Steps
- neurotransmitters are going to anufactured by the neuron
- Action potential goes down neuron causes vesicles to release neurotransmitter
- Neurotransmitter goes to synaptic cleft
- Bind to receptor on post synaptic cell or neuron
- Bind and cause activity in post-synaptic neuron
- the extra NT is reuptaked or reabsorbed or diffused
How drugs affect ANS?
- they work on synaptic transmission
- manipulation occurs here and allows for selective response better than axonal conduction. Alter one of 5 mechanisms.
1. increase synthesis -> increase effect
2. storeage
3. realease
4. binding
5. prevent the normal destruction and uptake- if NT is not reabsorbed there is more NT available that increases ANS effect
Acetylcholine is the NT for what?
- preganglionic neurons in Para and sympathtic NS
What about Post ganglion neurons
What NT is found in each?
In Para: NT is ACH
Receptors are: Nicotinic, Muscarinic
In Symp: Primary NT is NE except for in swat glands which is Ach.
- Adrenal medulla release epinephrine and works on alpha and beta receptors
Sympathetic Nervous system characteristics what happens with pupils, salivation, HR, breathing, digestion, glucose, bladder, sex organs?
- Fight or flight
- thoracic and lumbar nerves
- dilates pupils: need to see bear
- inhibits salvation: don’t need to eat while you are running from bear
- Accelerates heart: increases blood flow to brain
- Facilitates breathing: vasodialtion opens to get oxygen that can go to bloodstream
- inhibits digestion: dont need to eat
- stimulates release of glucose: glycogen storage is there for glucose breakdown in order to get to brain and muscles for energy
- secretes epi and NE good ol adrenal medulla that gets catechlines going
- relaxed bladder: allows for no urination
- inhibits sex organs: survival don’t need to have sex while running from bear and also prevents labor form happening relaxes uterus
Parasympathetic Division “REst and Digest”
-pupils, salicvation, HR, breathing, digestion, stimulation, bladder, sex organs
- keeps body alive and functioning
- affect cranial and sacral nerves
- couch potato
- pupils: constrict and gets smaller miosis and contraction of cilliary muscles and accomodate for near vision
- stimulates salivation: you need salivation for digestion for foods
- slows HR: if you ar resting dont need a lot of blood flow
- Constricts breathing not a lot of oxygen in lungs
- stimulates digestion: if you are eating you need
- gallblader stimulation: needed to digest fatty foods
- contracts bladder: detrusor muscle contracts to urinate
- stimulates sex organs: Netflix and chill
REd box on diagram: Sympathomimetics
think vasoconstriction
- mimics sympathetheic nervous system
- Adrenergic agonists
- used in emergency situations
-act on adenergic receptors - works on release of NE from nerve terminals
Used for effect on heart, lungs, blood vessels, nasal passages - alpha = blood vessels vasoconstriction
-beta 1 = heart - beta 2= lungs
What do anti- adernergic drugs do? blue box opposite of red
- Block Sympathetic nervous system action
- block action at receptors
- most widely used drugs
- deccreases the releas of Ne from nerve terminals
- blocking alpha or beta
- use for HTN since it lowers BP
- blocks heart decereases BP and HR
- drugs that blcok beta 2 cause bronchoconsticiton
- alpha SE: orthoststaic hypotension, reflex tachycardia, nasal congesiton, and impotence
-beta slow electrical conduction through heart and lower bp
Purple box
Parasympathetics/ Muscarinics
- mimics the parasympathtic nervous system
- Muscarinic receptor
- directely stimulates cholinergic receptors or indirectly stimulates by inhibiting acetylcholinerase
- two receptors: Muscarinic and nicotinic
- decrease BP, decrease HR, and increase peristalsis
Green box /anticholinergics/ Muscarinic antagonist
- blocks sch at muscarinic recetpors
- used to dry secretions, treat asthma, prevent motion sickness dialets pupil and dilates bronchi
SE: tachy, CNS stimulation, urinary retention, dry mouth, dry eyes, constipation, intolerance to heat
-Can’t spit, can’t shit, can ‘t pee
Muscurinic receptors effects (secretions, smooth muscle, HR, eye muscles, urinary bladder)
- Increased glandular secretions: pulmonary, GI/intestinal, sweat
- Contraction of smooth muscle: bronchi and GI tract
- slowing of HR
- Contraction of sphincter muscle of iris: miosis
- Contraction of ciliary muscle of eye: focus for near vision
- Voiding of urinary bladder: contraction of detrusor muscle and relaxation of trigone and sphincter muscles
Alpha 1 receptor (eyes, bvs, organs)
- dilation of Eyes, vasodilation Bvs, relation of bvs in male sex organs, prostatic capsule and bladder
Beta1 receptor
- Heart and kidney
- increase HR, increase force oof contraction, increase velocity of impulse through AV node.
- Kidney: increase renin-> angiotensin -> vasoconstriction
Beta 2 receptor
-Lungs bronchodilate, uterus relaxation, bvs, vasodilation, promote glycogenolysis
Bethanechol (Urecholine)
indication, action,
se: abdominal, secretions, bp effects, contraindications
- Parasympathetic agonist
- indication: postpartum or postoperative non obstructive urinary retention
- stimulates smooth muscle contaction in GI and urinary system
- SE: abdominal discomfoort, N/v/d, salication, flushing, sweating hypotension, brady
- Do not use in pts with asthma, bowel obstruction, or BPH
- Give 1 hour before meals (N/v with meals)
Atropine (uses,contraindications, SE)
SE: vision, HR, wet or dry?
- prototype of anticholinergic/ muscarinic antagonist: blocks parasympathetic actions of Ach and induces symptoms of fight or flight
- uses: increase HR in bradycardia, dilate pupils during eye exams (mydriasis) dilation , irritable bowel, suppress secretions during surgical procedures
- SE: drowsness, blurred vision, phtophobia, increased intraocular pressure, tachycardia, dry mouth, constipation, urinary retention, anhidrosis, tachycardia
- Contraindicated in glaucoma
What to do for an atropine overdose
HBDM
physostigmine (cholinesterase inhibitor) is antidote
- presents as psychosis
- hot as hades: blockade of sweat glands fever
- blind as a bat: pupils unable to constrict in bright light
- dry as a bone: salivary glands blocked
- Mad as a hatter: agitation and hallucinations
Adrenegic Agents: Catecholamine
Can they be taken orally, how long is action, can they cross BBB?
- Can’t be used orally due to rapid degredation
- brief duration of action
- cannot cross blood brain barrier
- They are broken down very quickly ussually a drip
EX: epi, Ne, isoproteronal, dopamine, dobutamine
