VF: Week 4 Sympathetic Nervous System

What are the neurotransmitters released at the autonomic ganglion and the adrenergic nerve terminal?

Norepinephrine

Acetylcholine

Epinephrine

Where is norepinephrine synthesized?

Adrenergic nerve terminal

Where is Acetylcholine synthesized?

Located in the Autonomic Ganglion

Where is epinephrine synthesized?

The Adrenal Gland

What pre-synaptic adrenergic receptor (AR) is linked to inhibition of norepinephrine release?

Alpha-2 AR

What is the Motor Structure Function?

The ANS and the SNS are almost entirely separated in the periphery.

How are the SNS and the ANS related to the CNS?

They are closely connected in the CNS.

What is the Function of the SNS?

Voluntary Controls the function of the skeletal muscle

What is the Function of the ANS?

Mainly regulated function of the internal organs and adapts them to the needs of the moment.

What is the Reciprocal Effect?

The effect that the parasympathetic and the sympathetic in which they counteract each other.

Are parasympathetic and sympathetic antagonist of each other?

No they are not they are complementary.

Fight or flight": Sympathetic

Regeneration: Parasympathetic

What is the origin of preganglionic neurons?

Throacolumbar region

Where are the preganglionic neurons found in the spinal cord?

Intermediolateral gray matter

What does most ganglia of the sympathetic system belong to?

The network of sympathetic chain ganglia that runs alongside the vertebral column

What is the ratio of preganglionic fiber to postganglionic fiber?

1:20

What is a ganglion?

A cluster of nerve cell bodies located outside the central nervous system. In the ANS, ganglia serve as relay points for transmitting signals between the central nervous system and target organs

Presynaptic ganglia: short

Postsynaptic ganglia: long

What does it mean when all preganglionic neurons are cholingeric?

They synthesize and release acetylcholine as their primary neurotransmitter.

Autonomic ganglia is always mediated by what neurotransmitter?

Acetylcholine

What is the receptor for the cholinergic?

Nicotinic

What cells in the adrenal medulla release epinephrine in the bloodstream?

Chromaffin Cells

What does it mean when a postganglionic neuron is adrenergic?

It means that they synthesize and release norepinephrine or noradrenaline as their primary neurotransmitter.

What are the receptors called that bind to the adrenergic receptors?

Alpha and beta

What is hidden?

ACH

What is hidden?

Adrenal Medulla

What is Hidden?

Adrenaline/Noradrenaline

What are the active adrenoceptors?

Alpha 1

Alpha 2

Beta 1

Beta 2

How does the sympathetic neurons and adrenal medulla effect the eyes?

Dilation of pupils (A1-AR)

How does the sympathetic neurons and adrenal medulla effect the Gastrointestinal activity?

Inhibits it with several receptors

How does the sympathetic neurons and adrenal medulla effect the Lungs?

Brochodilation (B2-AR)

How does the sympathetic neurons and adrenal medulla effect the Heart?

Increased heart rate:

Cardiac output (B2-AR)

Vasoconstriction (increase in BP) (A1-AR)

How does the sympathetic neurons and adrenal medulla effect the BG?

Increases the BG concentration (A2-AR)

How does the sympathetic neurons and adrenal medulla effect insulin?

Inhibits insulin release (B2-AR) by stimulating glugagon release

How does the sympathetic neurons and adrenal medulla effect the Blood supply?

Increases the blood supply to the skeletal muscles

What G-protein coupled membrane receptor (GPCR) stimulation leads to Bronchodiluation?

B2-AR

What type of receptor is Phenylephrine an agonist?

a1-adrenergic receptor

What doe a sympathomimetic mean?

mimics sympathetic dilution

What are the uses of Phenylephrine?

dilutes pupils

Vascoconstriction

What are the side effects of phenylephrine?

High blood pressure

What kind of adrenergic receptor is Phenylpropanolamine an agonist?

A1-adrenergic receptor

What are the uses of Phenylpropanolamine?

Constriction of the inner sphincter of the urinary bladder for incontinance or urinary dribbling

What are the side effects of Phenylpropanolamine?

Tachycardia and High blood pressure

What adrenergic receptor is Brimonidine Tartrate an agonist?

A2-adrenergic receptor

What are the effects of Brimonidine Tartrate?

Reduces intraocular pressure

How does Brimonidine Tartrate reduce intraocular pressure?

Decreases Aqueous humor production

Increasing aqueous humor outflow

What is the Therapeutic use of Brinonidine Tartrate?

Glaucoma

What is Glaucoma?

Increase of the intraocular pressure

How is Glaucoma harmful?

Fluid cannot drain from the eye causing increase in IOP. Prolonged high IOP can damage optic nerve and result in blindness

What type of adrenergic receptor is Xylazine an agonist?

A2-adrenregic receptor

What is the Mechanism of action for Xylazine?

Activation of presynaptic A2-adrenergic in the brainstem and spinal cord, leading to decreased sensorial or descending motor sympathetic outflow.

What are the effects of Xylazine?

Produces sedation, muscle relaxation, and analgesia

What animals are mostly effected by Xylazine?

Horses

cattle

large animals

Deer

What is the therapeutic use of Xylazine?

Anesthetic premedication

Sedation

Total IV anesthesia

Vomiting in cats

What are the adverse effects of Xylazine?

Brachycardia

Heart Conduction disturbances

What is the adrenergic receptor for Detomidine and Romifidine?

A2-adrenergic receptor

What is the mechanism of action for Detomidine and Romifidine?

Activation of presynaptic A2-adrenergic receptors in brainstem and spinal cord, leading to decreasing sensorial or descending motor sympathetic outflow

What are the effects and uses of Detomidine and Romifidine?

Sedation and anesthetic premedication, IV anesthesia in horses

What are the adverse effects of Detomidine and Romifidine?

Bradycardia

Heart Conduction Disturbances

What is the adrenergic receptor for Medetomidine?

A2-adrenergic receptor

What is the adrenergic receptor for Dexmedetomidine?

A2-adrenergic receptor

What is the effects and uses of Medetomidine?

Sedative with analgesic action in small animals and horses

What are the effects and uses of Decmedetomidine?

emetic in cats

Treat emergence delirium following anesthesia

What drug could be used for treating hyptension associated with anesthesia?

Phenylephrine

What is the Adrenergic receptor for Isoproterenol?

B adrenergic receptor

What are the effects of Isoproterenol?

Increases the force of contraction

The rate

Conductivity of the heart impulses

Vasodilation

Urine Relaxation

What does a non-selective adrenergic receptor mean?

Doesn’t respect receptor types such as B1 and B2

What does tocolytic effect mean?

Urine relaxation

What are the therapeutic uses of Isoproterenol?

Brachycardia

heart block

What are the adverse effects of Isoproternol?

Tachycardia

Arrhythmias

What type of adrenergic receptor is Dobutamine an agonist?

B1 adrenergic receptor

What are the effects of Dobutamine?

Increase the myocardium force of contraction

Heart rhythm is stable but depends on the dos and species

What is the Therapeutic uses of Dobutamine?

Congestive heart failure

Hypotension during surgery by increasing CO

What are the adverse effects of Dobutamine?

Increases AV conduction

Tolerance (tachyohylaxis)

What type of adrenergic receptor is Terbutaline an agonist?

B2 adrenergic receptor

What is the mechanism of action and effects of Terbutaline?

Produces relaxation of smooth muscle found principally in bronchial, vascular and uterine tissues.

What are the therapeutic uses of Terbutaline?

Brochodilater: treats asthma

Particularly used in cats

What is the adverse effects of Terbutaline?

Tachycardia

What is the adrenergic receptor for Clenbuterol agonist?

B2 adrenergic receptor

What is the mechanism and the effect of Clenbuterol?

Bronchodilator

Banned in food-producing animals due to anabolic/performance enhancer in human consumers.

What sympathomimetic drug can be used as part of the treatment of acute congestive heart failure in dogs?

Dobutamine

What are the three types of a-adrenergic receptor antagonists?

Non-selective

Selective A1

Selective A2

What is a non-selective alpha-adrenergic receptor?

Works on any alpha receptor

What are examples of Non-selective a-adrenergic antagonists?

Phenoxybenzamine

ACP

What is an example of a Selective A1 adrenergic anatgonist?

Prazosin

What is an example of Selective A2 adrenergic antagonsit?

Yohimnine

Atipamezole

What are the two type of B adrenergic antagonists?

Non selective

Selective B1

What are examples of non-selective B-adrenergic anatagonist?

Propanolol

Timolol

Satalol

What is an example of a selective B1 antangonist?

Atenolol

What type of receptor is for the Phenoxybenzamine antagonist?

A-adrenergic receptor

What does Phenoxybenzamine do to the receptor?

Irreversible inhibition of the a-adrenergic receptor

What are the pharmacological actions fo Phenoxybenzamine?

Prevents vasoconstriction of peripheral blood vessels

What is the theraputic use of Phenoxynenzamine?

Tumor of the adrenal gland medulla (pheochromocytoma)

Reduces urinary sphincter tone and allow easier urination

What type of receptor is used for Acepromazine (ACP) antagonist?

A-adrengenic

What is the mechanism and use of ACP?

Phenothiazone tranquilizer that blocks dopamine receptors in CNS and depresses reticular-activity resulting in sedation

What is does ACP block?

Dopamine

A-adrenergic receptor

Is ACP and analgesic?

No, but potentiates the effects of analgesic drugs

What are the effects of ACP?

Sedation without significant respiratory depression

Systemic BP can be reduced due to vasodiluation.

Vagally-induced Bradycardia

Antiemetic

Antihistaminic

Antisympathetic

Antiarrhythmic

Antishock

What receptor is used for Prazosin antagonist?

A1 adrenergic

What are the effects of Prazosin?

decreased peripheral resistant and lowers BP

Reflex tachycardia is less significant caused by beta receptors