Chapter 4 Flashcards
What is the structure of a neuron?
Dendrite- That recieve signals
Soma (cell body)
Nucleus
Myelin Sheath
Axon- sends electrical impluses
Axon terminal button
Neurons communicate through synapses where neurotransmitters are released and bind to receptors on other neurons or effectors.
How are neurotransmitters released from and act on neurons?
Neurotransmitters are released from the axon terminals into the synaptic cleft. Once released, they bind to specific receptors on the postsynaptic neuron or effector, initiating a response. For example, acetylcholine (ACh) can bind to cholinergic receptors.
What neurotransmitter is released from **sympathetic preganglionic axons? **Postganglionic axons?
Neurons release acetylcholine (ACh), while postganglionic neurons primarily release norepinephrine (NE)
What neurotransmitter is released from parasympathetic preganglionic axons? Postganglionic axons?
Both parasympathetic preganglionic and postganglionic neurons release acetylcholine (AcH)
What happens in the body when the parasympathetic system is activated?
- Stimualtes flow of saliva
- Slows heartbeat
- Constricts bronchi
- Stimulates peristalsis(flow of food) and secretion
- Stimulates release of bile
- Contracts bladder
What happens in the body when the sympathetic system is activated?
- Dilates pupil
- inhibits flow of saliva
- Accelerates heartbeat
- dilatea bronchi
- inhibits peristalsis and secretion
- coversion of gylcogen to gluosee
- secretion of adrenaline and noradrenaline
- Inhibits contraction
How are agonist and antagonist of the autonomic nervous system named?
Cholinergic drug (mimics or blocks acetycholine) and adrenergic drugs (mimic or blocks nonepinephrine and epinephrine.
What kind of cholinergic receptors are there? And where is each type located?
Muscarinic- (agonist) it contracts the smooth muscles within the bronchioles, increases SLUD and decreases heart rate.
Nicotinic- contraction of skeletal mucles
What are the pharmacologic effects of parasympathomimetics?
- induce resting adn digesting responses
* . constrict pupils
* decrease heart rates
* constricts bronchioles
* increases GI activity
* SLUD activities - Can be used to treat
* xerostomia
* unirnary retention
* glaucoma
* myasthenia gravis
What are the therapeutic uses of parasympathomimetics?
It treats
* nicotinic receptor activity direct acting- nicotine addition
* primarily muscarinic receptor activity direct acting- urinary rention, low GI activity, glaucoma, xerostomia.
* primarily muscarinic receptor activity indirect acting- alzheimers, myasthenia gravis
What are the adverse reactions for parasympathomimetics?
- Bradycardia
- Pupil constriction
- Bronchial constriction
Can occur at a normal consentration or regular dose
When shouldn’t a person take a parasympathomimetic?
Asthma
Peptic ulcers
Hyperthyroidism
GI or Urinary Obstruction
What are the pharmacologic effects of anticholinergics?
- They are an antagonist that blocks the parasympathetic responses
- Anticholinergics block resting and digesting Responses
What are the therapeutic uses of anticholinergics?
- Motion sickness
- Hypersalivation
- Unrinary incontinence
- Irritable bowel syndrome (IBS)
- Chronic Obstructive pulmonary disorder (COPD)
- Skeletal muscle tension
Muscarinic receptors anatagonist have a varitey of uses what are they?
Atropine- cardiac arrhythmias COPD
Scopolamine- Motion sickness
Diphenydramine- allergies
Tolterodine-urinary incontience
Nicotinic receptor antagonist are used during surgeries to relax skeletal muscles what are they?
Atracurium
Pancuronium
What are the adverse reactions of anticholinergics?
- Xerostomia
- Blurred vision
- Urinary retention
- GI retention or constipation
- Increase respiration
When shouldn’t a person take anticholinergics?
When they have Glaucoma
Cardiovascular disease
GI or urinary obstruction
What drug interactions might cause a adverse reaction when a patient is using a anticholinergic drug?
- Other Anticholinergic medications
- Tricyclic Antidepressants
What kinds of adrenergic receptors are there? Where is each type located?
α1 receptors: Located in smooth muscle, causing contraction in the pupil and genitourinary system and increased blood pressure.
α2 receptors: Located in the CNS, decreasing blood pressure, insulin secretion, lacrimation and neurotransmitter/NE secretion.
β1 receptors: Located in the heart, increasing heart rate and contractility.
β2 receptors: Located in Lungs, smooth muscle (lungs, blood vessels, heart, kidney), causing relaxation.
β3 receptors (increases blood glucose levels): Located in fat tissue, stimulating fat breakdow
What are the pharmacologic effects of sympathomimetics?
- induces fight or flight,
What are the therapeutic uses of sympathomimetics?:
Sympathomimetics treat conditions like asthma, nasal congestion, anaphylaxis, ADHD, and low cardiac output
Opens constricted vessels
What are the effects of sympathetic agonists on the different adrenergic receptors?
All are direct acting:
α1 agonists: Increase blood pressure and treat nasal congestion.
α2 agonists: Decrease blood pressure and treat ADHD.
β agonists: Dilate bronchioles and treat asthma, treat low cardiac output.
Non-specific- anaphylaxis-epinephrine
When shouldn’t a person take a sympathomimetic?:
angina pectoris, hypertension, hyperthyroidism, and low gastric motility
What are the adverse reactions of sympathomimetics?:
xerostomia, cardiac arrhythmias, tachycardia, hypertension, and tremors
what are the drug interactions for sympathomimetics?
Tricyclic antidepressants
Epinephrine in Local anesthetics
Other Adrenergic stimulants
What are the pharmacologic effects of adrenergic antagonists?:
Adrenergic antagonists prevent “fight or flight” responses, such as lowering blood pressure and reducing heart rate
What are the therapeutic uses of adrenergic antagonists?:
used to treat hypertension, migraines, glaucoma, and prostate hypertrophy
What are the adverse reactions of adrenergic antagonists?:
Adverse reactions include decreased systolic blood pressure, bradycardia, and dizziness
When shouldn’t a person take adrenergic antagonists?
asthma and hypotension, other antihypertensive drug including diuretics
