UNIT 2 EXAM Flashcards
Nervous System
functions to control and coordinate activity of all systems in the body;
involuntary and voluntary control;
2 subdivisions: peripheral
central
Central Nervous System (CNS)
brain and spinal cord;
receives and interprets info; initiates motor responses
Peripheral Nervous System (PNS)
afferent nerves, efferent nerves;
12 cranial nerves;
31 spinal nerves;
somatic & autonomic
Somatic Nervous System (SNS)
nerves branch from cranial and spinal nerves;
innervates skeletal muscle;
voluntary control by cerebral cortex
Autonomic Nervous System (ANS)
visceral;
branches of cranial and spinal nerves;
innervates cardiac muscle and smooth muscle of organs and glands;
involuntary control;
regulated by hypothalamus and medulla oblongata;
made up of ganglia (collections of synapses)
authorhythmicity
contraction without any stimulus
homeostasis
a process that keeps the internal organs at a state of dynamic equilibrium
preganglionic nerve
extends from the spinal cord
postganglionic nerve
extends from the ganglia, it receives a signal from the preganglionic nerve;
it sends a signal to an effector organ or gland
Neurotransmitters (NT)
keep impulses going, chemical substance, stimulates an internal organ or gland to produce a change/ action by binding to receptors
Sympathetic Nervous System
fight, flight, fright;
adrenergic;
regulates activity of internal organs and glands during physical and mental stressful situations;
adrenal medulla releases EPI and NE
Parasympathetic Nervous System
rest and digest;
cholinergic;
Neurotransmission of Sympathetic Nervous System
Acetylcholine (ACH) released at ganglia onto nicotinic 1 (Nn) receptors of the postganglionic nerve;
Norepinephrine (NE) released by postganglionic nerve onto the effector gland or organ;
synthesized from dopamine
Epinephrine (EPI)
a hormone released by the adrenal medulla;
acts on adrenergic receptors
Dopamine (DA)
sympathetic and CNS neurotransmitter;
precursor to NE;
stimulates many receptors (alpha, beta, dopaminergic)
Sympathetic (some)/Adrenergic Receptors (all)
alpha-1, alpha-2, beta-1, beta-2
Alpha-1 Receptors
found on glands, smooth muscles, eyes, most arteries and veins;
smooth muscle contraction and vasoconstriction;
mydriasis;
stimulated by EPI and NE;
release of NE and EPI by the adrenal medulla
Alpha-2 Receptors
relaxation/inhibition (parasympathetic response);
decreases contraction of smooth muscle of the vessels (vasodilation);
decreases release of NE/regulates the release
negative feedback loop
Beta-1 Receptors
located on the heart;
stimulated by EPI and NE;
increases heart rate, force of contraction, and strength of AV conduction
Beta-2 Receptors
stimulated by EPI only;
located on smooth muscle (lungs and uterus), skeletal muscle arteries, and coronary arteries;
smooth muscle relaxation (lungs and uterus);
bronchodilation;
uterine relaxation;
relaxation of the coronary arteries and skeletal muscle arteries - vasoldilation
Effects from Sympathetic Stimunlation
release of EPI & NE from adrenal medulla;
vasoconstriction of the arteries (exceptions: arteries of the skeletal muscle and coronary arteries that are dilated);
increased HR;
increased force of contraction;
increased AV conduction;
decreased GI motility (smooth muscle contraction);
postganglionic NT released: NE;
mydriasis (pupils);
bronchodilation;
relaxation of the urinary bladder;
contraction of the urinary sphincter;
glycogen to glucose (energy is used)
Vasocontrcition
high rate of sympathetic nerve firing;
increases blood pressure but reduces blood flow
Sympathomimetic Effects
when drugs mimic the sympathetic nervous system (adrenergics, adrenergic agonists)
Vasodilation
low rate of sympathetic nerve firing;
decreases blood pressure bur increases blood flow
Sympatholytics
when drugs work against the sympathetic nervous system (adrenergic blocking, adrenergic blockers/inhibitors/antagonists)
ALPHA-1 Adrenergic Agonists
alpha-1 receptor is stimulated;
contraction of smooth muscle, vasoconstriction (increased BP);
vasoconstriction in nasal passages - shrinks swollen mucous membranes (decongestant effect);
DRUGS:
ephedrine - increases BP
phenylephrine (Neo-Synephrine) - increases BP, nasal decongestant
CLINICAL USE:
increases BP;
nasal decongestant;
increases circulation of vital organs
CONCERN: hypertensive and cardiac patients (in case of excessive vasoconstriction)
PATIENT TEACHING/SIDE EFFECTS: slows digestion/urination;
excessive nasal dryness
Adrenergic Agonists (ALPHA-1, BETA-1, BETA-2)
stimulates alpha-1, bet-1 and beta-2 receptors;
vasopressor - vasoconstriction; higher BP;
cardiac stimulator;
bronchodilator;
DRUGS:
epinephrine (Adrenalin)
USES: severe allergic reactions/anaphylaxis, shock, cardiac arrhythmias;
PATIENT TEACHING/SIDE EFFECTS: increased heart rate and BP
ALPHA-1 Adrenergic Blockers
binds to alpha-1 receptors and blocks them;
vasodilation (decreased BP);
relaxation of smooth muscle;
relaxation of the smooth muscle of the uterus (increases urine flow)
DRUGS:
prazosin (Minipress);
doxazosin (Cardura);
terazosin (Hytrin)
USES: hypertension, benign prostatic hyperplasia
PATIENT TEACHING/SIDE EFFECTS:
orthostatic hypotension (BP decreases when a patient stands up) - caution with position changes, reflex tachycardia (when BP decreases, heart betas faster to raise it), GI upset, increased urination
BETA-1 Adrenergic Agonists
MOA:
low dose stimulates dopaminergic (d-1) receptors in the kidneys causing vasodilation and increased renal blood flow;
moderate dose stimulates beta-1 receptors; this increases heart rate, force of contraction, cardiac output;
high dose stimulates alpha-1 receptors causing vasoconstriction (increase in BP);
DRUGS:
dobutamine
USES:
treatment of shock, increases BP, and increases heart function with acute heart failure
PATIENT TEACHING/SIDE EFFECTS:
overstimulation of the heart, CNS irritation
BETA-2 Adrenergic Agonists
stimulates beta-2 receptors;
relaxes smooth muscle of the lungs, causing bronchodilation;
relaxes smooth muscle of the uterus
DRUGS:
albuterol (Proventil, Ventolin, Accuneb) - bronchodilator;
terbutaline (Brethine) - bronchodilator, uterine relaxant;
formoterol (Foradil) - bronchodilator;
salmeterol (Serevent) - bronchodilator;
USES:
asthma, respiratory illness/disease, pre-term labor
PATIENT TEACHING/SIDE EFFECTS:
tachycardia, jittery, tremors, headache
Selective BETA-1 Blockers
beta-1 receptors are blocked (antagonizes beta-1 effects of EPI and NE);
decreases force of contraction;
decreases AV conduction;
decreases HR;
decreases cardiac output, decreasing BP;
USES:
HTN, angina, arrythmias, tachycardia, migraines, glaucoma (decreases IOP); heart failure (decreases sympathetic activity)
DRUGS:
atenolol (Tenormin);
metoprolol (Lopressor)
PATIENT TEACHING/SIDE EFFECTS:
drowsiness, GI upset, CNS depression, bradycardia, monitor serum lipid levels, mental depression, monitor glucose levels in diabetics
Non-Selective Beta Blockers (BETA-1 & BETA-2)
blocks beta-1 & beta-2 receptors;
decreases HR, force of contraction, conduction, cardiac output, lowering BP;
causes bronchoconstriction
USES:
HTN, arrythmias, angina, tachycardia, migraines, glaucoma (decrease IOP), heart failure ( decreases sympathetic activity)
DRUGS:
nadolol (Cogard);
propranolol (Inderal);
timolol (Blocarden);
CONTRAINDICATION: asthma and respiratory disease patients, can trigger respiratory distress
PATIENT TEACHING/SIDE EFFECTS:
drowsiness, GI upset, CNS depression, bradycardia, monitor serum lipid levels, mental depression, monitor glucose levels in diabetic patients
Parasympathetic Sympathetic Nervous System
“Rest and Digest”;
restoration of energy stores;
balance;
stimulates one specific body part/system;
NT is CH at ganglia and postganglionic cells
Vagus Nerve
10th cranial nerve;
parasympathetic fibers;
branches to the larynx, pharynx, heart, lungs, blood vessels, and digestive areas;
responsible for parasympathetic responses: slows heart rate, bronchoconstriction, decreases blood pressure, relaxes the smooth muscle of the GI tract, urinary sphincter; contracts the urinary bladder;
gag reflex, sweating, speaking;
sudden stimulation causes drop in HR and BP;
can result in syncope
3 types of cholinergic reeptors
muscarinic (receptors in cardiac and smooth muscle and glands; at parasympathetic postganglionic nerve endings; decreases HR, cause bronchoconstriction, increases digestion and urination, causes miosis)
nicotinic 1 (Nn) - receptors at ganglia of sympathetic and parasympathetic postganglionic nerves (synapse area)
nicotinic 2 (Nm) - receptors found at skeletal muscles; if stimulated muscle contracts
all are stimulated by ACH
Parasympathomimetics
when drugs mimic parasympathetic nervous system (cholinergic agonists, cholinergics)
Parasympatholytics
when drugs block receptors on the organs and glands of the parasympathetic nervous system (cholinergic antagonists, anticholinergics)
Cholinergics/Parasympathomimetics (Direct-Acting Agonists)
directly bind and stimulate muscarinic (cholinergic) receptors in the parasympathetic division;
mimic ACH;
DRUGS:
acetylcholine (ACH) - used for for miosis; cataract and other eye surgeries;
pilocarpine (Pilocar) - used for glaucoma; causes miosis to decrease fluid in the eye; decreases IOP;
bethanecol (Urecholine) - used for urinary retention and ileus/intestinal stasis; stimulates muscarinic receptors of the bladder and the GI tract to prevent constipation and urinary retention post-op and in the elderly
Cholinergics/Parasympathomimetics (Indirect-Acting Agonists)
inhibit acetylcholinesterase (the enzyme that destroys ACH), thus increasing ACH;
DRUGS: neostigmine (Prostigmin)
USES:
treat urinary retention and ileus/intestinal statis; reverses actions of rocuronium bromide (Zemuron) that causes respiratory paralysis from anesthesia by increasing levels of ACH at the nicotinic 2 (Nm receptors) on skeletal muscle; treatment for myasthenia gravis (antibodies attack Nm/N2 receptors)
ANTIDOTE for overdose on anticholinergics: physostigmine (Eserine) - cholinergic
Cholinergic Side Effects and Patient Teaching
S: salivation
L: lacrimation
U: urinary incompetence
D: defecation
G: gastrointestinal distress
E: emesis
Anticholinergics/Parasympatholytics
bind to the muscarinic receptors, blocking ACH;
DRUGS:
atropine - antidote for cholinergic poisoning; increases HR; decreases vagus nerve activity; pre-op med: slows digestion and urination; mydriasis;
dicydomine (Bentyl) - used for GI disorders (ulcers, colitis, IBS), decreases GI motility and secretions;
ipratropium bromide (Atrovent) - bronchodilation;
PATIENT TEACHING/SIDE EFFECTS:
dry mouth, visual disturbances, urinary retention, constipation, tachycardia
Swear Glands
Eccrine and Appocrine Glands
Eccrine Glands
non-hairy areas, through skin pores;
sympathetic cholinergic control;
muscarinic receptors;
stimulated by ACH;
regulated body temperature at all times
Apocrine Glands
hairy areas, through hair follicles and then through skin;
sympathetic adrenergic control;
alpha-1 receptors;
stimulated by EPI & NE;
used to cool down when expending energy
Parkinson’s Disease
decreased levels of dopamine;
leads to excessive ACH activity (excess motor activity, tremors, muscle rigidity, brady kinesia, posture/balance difficulty);
Anti-Parkinson’s drug therapy: increase DA, decrease metabolism of DA, stimulate DA receptors;
Anti-Cholinergics: block ACH, reduce symptoms of tremor and rigidity
Somatic Nervous System
voluntary;
skeletal muscle contraction;
impulses originating in CNS to the somatic motor neurons;
neurons connect wit skeletal muscle fibers = neuromuscular junction (NMJ);
ACH acts on nicotinic 2 (Nm) receptors: respirations, contractions of diaphragm and chest muscles, tone for movement, tone for movement, body posture
