Term
What are preganglionic and postganglionic neurons and where are they found? |
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Definition
| The preganglionic & postganglionic neurons are efferent neurons found in the involuntary nervous system. The preganglionic neuron travels from the CNS to the ganglia. The postganglionic neuron travels from the ganglia to effector cell. |
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Term
How many efferent neurons in the SNS, PNS, voluntary portion of the nervous system? |
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Definition
SNS- 2 neurons PNS- 2neurons Voluntary- 1 neuron |
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Term
| What neurotransmitter stimulates adrenergic receptors and what are the different types of adrenergic receptors and where are they located. |
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Definition
Adrenergic receptors normally respond to norepinephrine neurotransmitter release in the body. Location: vasculature, heart, smooth muscle wrapping around brochiole. Alpha (a) adrenergic receptors- contracts smooth muscle. Found in Peripheral blood vessels, vasculature. Beta1 (B1) adrenergic receptors- stimulates heart rate, strength. Heart is major place found. Beta2 (B2) adrenergic receptors- relaxes smooth muscle, increases metabolic rate. (bronchiole tree) |
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Term
What are the the 2 types of cholinergic receptors, location, and what is the neurotransmitter that stimulates them? |
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Definition
The 2 types of cholinergic receptors are muscarinic cholinergic receptors & nicotinic cholinergic receptors. found especially in smooth muscle of hollow organs nuerotransmitter: acetycholine |
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Term
| What are some of the characteristics of the muscarinic cholinergic receptors? |
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Definition
- they are parasympathetic neuron sys receptors chiefly found at effector after postganglionic neuron.
- contracts smooth muscle (except GI and urinary sphincters, & blood vessels). The eye "sphincter" is under parasym. cause it is truly an eye mucsle not sphincter.
- stimulates exocrine glands (sweat glands)
- decreases heart rate & sometimes contractility
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Term
| What are some characteristics of nicotinic cholinergic receptors? |
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Definition
- found at ganglia, neuromuscular junctions, and the adrenalmedulla
- may stimulate both the sympathetic and the parasympathetic system simultaneously. (stimulates bothe sym. and parasym. ganglia)
- stimulates adrenal medulla (sym. like effect)
- stimulates skeletal muscle (neuromuscular junction)-voluntary system.
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Term
| Why would you want to stimulate a nicotinic receptor if it seems to have many side effect? |
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Definition
| You want to stimulate a nicotinic receptor when you want control over a skeletal muscle because the only receptor found at the skeletal muslce is the nicotinic cholinergic receptor. |
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Term
| review charts in appendix a |
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Definition
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Term
What neurotransmitter stimulated skeletal muscle and what is the receptor |
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Definition
Neurotransmitter: acetylcholine receptor: nicotinic cholinergic receptor |
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Term
How is neurotransmitter action stopped? Which neurotransmitter is degraded at the receptor? Which is recycled back into the presynaptic neuron? |
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Definition
Depending on transmitter substance, stimulation may be stopped by: 1) use of an enzyme to destroy the transmitter (AcH destryed by cholinesterase*) (NE destroyed by MAO in presynaptic terminal & COMT in postsynaptic cell) 2) REUPTAKE of the transmitter into neuron A. Whatever doesn't bind to receptor gets recycled back to preganglionic neuron. (NE's- most important removal mechanism) |
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Term
| What are the main indications and contraindications for alpha agonists |
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Definition
INDICATIONS
-used to treat allergic reactions by causing vasoconstriction and reducing edema.
-treats hypotension(blood goes to venus system but not to heart), like that caused in spinal anesthesia, by stimulating alpha receptors to clamp down on muscles and increase blood pressure and increase beta 1 receptors to heart which increases heart rate and contractility.
-used for nasal congestion-use as nose spray--fewer side effects. Local vasoconstriction which decreases feeling of pressure in nose.
-used with local anesthetics to delay absorption (longer acting with fewer central side effects).
-used a a topical hemostatic (something that stops bleeding), dentist, professional sports, nosebleeds.
-Dilates pupil for eye exam by stimulation of alpha receptors in eye causing constriction of radial muscle causing pupil dilation.
CONTRAINDICATIONS
-Angina (not able to supply enough blood with demand of heart). Stim of alpha receptors increases heart work load.
-Hypertension: alpha stimulation increase BP dramatically. |
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Term
| What are main indications and contraindications for beta agonists? |
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Definition
INDICATIONS:
allergic reactions:
-B2 receptors can reverse bronchiolar constriction.
-B1 can increase cardiac output.
-B2 is used for chronic obstructive pulmonary disease.(ex. asthma emphysema chronic bronchitis)Inhalation causes fewer side effects than oral or sublingual.
-used in hypotension by stimulating beta1 receptors in heart which increases heart rate and increases contractility, increasing BP.
-Prolonged shock (circulatory failure). Using a Beta agonist vasodialator such as isoproterenol or dopamine, which has an independent vasodilator effect. B1 will increase heart rate and contractility and B2 dilates critical vessels.
CONTRAINDICATIONS:
-angina-b1 increases heart workload.
-hypertension-b1 but to a lesser extent than alpha
-hyperthyroidism-B2 stimulation increases metabolism more & b1 increases heart palpitations and makes symptoms worse. |
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Term
| Name indications and contraindications for alpha antagonists |
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Definition
indications:
-locally-prevent local necrosis following Norepi overdose
-in patient in shock restores sequesterd fluid in circulation
-Pheochromocytoma (tumor of adrenal gland) first diagnos to see if this is the cause of hypertension. Use preoperative treatment used to gradually remove stimulation (otherwise a drastic decrease in BP will occur when tumor is removed)
CONTRAINDICATIONS:
-asthma: do not use alpha agonist if one has asthma
-hypotension
-congestive heart failure
caution: diabetes |
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Term
| What are indications and contraindications for beta antagonists |
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Definition
INDICATIONS: 1)cardiac arrythmias 2)prevention of angina by decreasing workload 3)hypertension 4)controlling signs of thyrotoxicosis-counteracts (tachycardia, high b/p increase) 5)Prophylaxis of migraine headaches and, perhaps treatment of acute attacks. CONTRAINDICATIONS: Asthma Hypotension (unless with arrhthmisa requiring treatment) Congestive heart failure, heart block caution: Diabetes |
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