23 - ANS Flashcards by Staci Thomas

The ______ can change visceral function rapidly and intensely:

– Heart rate can be increased to twice normal within 3-5 seconds

– Arterial pressure can be doubled within 10-15 seconds

– Sweating can begin within seconds

ANS

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In the ANS, terminal ends of these fibers usually have enlarged varicosities where neurotransmitter and large numbers of _______ are stored.

Mitochondria

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The efferent activity of the ANS is largely regulated by reflexes (not spinal reflexes). A ________ reflex is located in the major systemic arteries sensing blood pressure. If BP decreases, sensory impulses to the vasomotor center of the brainstem decrease. Heart rate increases and vascular resistance increases.

Baroreceptor

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The ANS pathways consist of two ______ in sequence.

Neurons

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The ANS preganglionic neuron cell bodies are located within the ______, its axons are ________ and its neurotransmitter is _______.

CNS
Myelinated
ACh

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The ANS postganglionic neuron cell bodies are located in the ________ ________, its axons are not ________, and its neurotransmitter is ______ in the parasympathetic system and ________ (usually) in the sympathetic system.

Peripheral ganglia
Myelinated
ACh
Norepinephrine

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In the ANS, (PARASYMPATHETIC/SYMPATHETIC) glands cause secretion of large amounts of sweat. (CHOLINERGIC/ADRENERGIC) to most sweat glands, which means they are sympathetic neurons using ACh. There are a few (CHOLINERGIC/ADRENERGIC) fibers in palms and soles. This is actually a parasympathetic function distributed via sympathetic fibers.

Sympathetic
Cholinergic
Adrenergic

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In the ANS, (PARASYMPATHETIC/SYMPATHETIC) glands strongly stimulates the lacrimal, nasal, salivary and GI glands of upper tract. Note that glands of lower GI tract are mostly stimulated via the _______ system.

Parasympathetic

Enteric

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In the heart, (PARASYMPATHETIC/SYMPATHETIC) stimulation increases heart rate and strength of contraction.

Sympathetic

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In the heart, (PARASYMPATHETIC/SYMPATHETIC) stimulation decreases heart rate and strength of contraction.

Parasympathetic

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In the systemic blood vessels, (PARASYMPATHETIC/SYMPATHETIC) stimulation constricts most blood vessels while (PARASYMPATHETIC/SYMPATHETIC) stimulation has almost no effect.

Sympathetic

Parasympathetic

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In arterial pressure, (PARASYMPATHETIC/SYMPATHETIC) stimulation decreases pumping of heart but has little effect on blood pressure.

Parasympathetic

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In arterial pressure, (PARASYMPATHETIC/SYMPATHETIC) stimulation results in acute increase in arterial pressure but little effect long term.

Sympathetic

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In general, the (PARASYMPATHETIC/SYMPATHETIC) stimulation inhibits most of the endodermal structures (GI, Respiratory, Endocrine, Auditory, Urinary).

Sympathetic

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In general, the (PARASYMPATHETIC/SYMPATHETIC) stimulation excites most of the endodermal structures.

Parasympathetic

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In the eyes, (PARASYMPATHETIC/SYMPATHETIC) stimulation results in pupil constriction and lens focusing.

Parasympathetic

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In the eyes, (PARASYMPATHETIC/SYMPATHETIC) stimulation results in pupil dilation.

Sympathetic

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In the GI tract, (PARASYMPATHETIC/SYMPATHETIC) stimulation results in a strong stimulation that inhibits peristalsis. The GI tract is normally not dependent on this type of stimulation.

Sympathetic

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In the GI tract, (PARASYMPATHETIC/SYMPATHETIC) stimulation promotes peristalsis and relaxes sphincters.

Parasympathetic

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The cell body of each sympathetic preganglionic neuron lies in the intermediolateral horn of the ______ _____ (CNS).

Spinal cord

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The sympathetic preganglionic fiber can synapse with postganglionic neurons upward or downward in the paravertebral chain, interconnected with _______ nerves.

Spinal

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T/F. The sympathetic preganglionic fiber can pass for variable distances through the chain and then through one of the sympathetic nerves to synapse in a peripheral sympathetic ganglion.

True

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All preganglionic nerves are (CHOLINERGIC/ADRENERGIC).

Cholinergic

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Postanglionic sympathetic fibers pass through the ______ rami, are type C fibers, and make up about 8 percent of the fibers in the average nerve.

Gray

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(PREGANGLIONIC/POSTGANGLIONIC) sympathetic fibers innervate muscle to constrict blood vessels, piloerect hair, and change heart rate and force of contraction.

Postganglionic

The ________ sympathetics supply the face and thoracic viscera and are considered postsynaptic.

Cervical

The cervical sympathetic postganglionics are from what ganglia?

Superior, middle, and inferior cervical ganglia | T1-T5 paravertebral ganglia

The cervical sympathetic postganglionics exit the chain as direct fibers and travel downwards to enter the thorax as cardiopulmonary _________ nerves.

Splanchnic

The cardiopulmonary ________ nerves travel on their own and do not accompany other nerves or vessels. They function in coronary artery dilation, increase heart rate, and bronchodilation.

Splanchnic

The thoracic sympathetic chain lies against the neck of ribs and costovertebral junctions. They are made up of 12 thoracic ganglia pairs, the first one is often fused with inferior cervical ganglion going to the head and is referred to as the ________ ganglion collectively.

Stellate

Splanchnic nerves are composed of preganglionic fibers and visceral sensory fibers. They supply the abdominal viscera and synapses in the prevertebral ganglia. All preganglionic neurons are _________.

Cholinergic

This splanchnic nerve is from T5-T9 and synapses in the celiac ganglion.

Greater

This splanchnic nerve is from T10-T11 and synapses in the superior mesenteric ganglion.

Lesser

This splanchnic nerve is from T12 and synapses in the aorticorenal ganglion.

Least

This splanchnic nerve is from L1-2 and synapses in the superior and inferior mesenteric ganglion.

Lumbar

Put the following steps of post-ganglionic neurotransmitter synthesis of norepinephrine in order: A. Hydroxylation of dopamine to norepinephrine B. Hydroxylation of tyrosine to dopa C. Transport of dopamine into the vesicles D. Decarboxylation of dopa to dopamine E. Once the neuron is stimulated, NE is released, where it binds to receptors depending on affinity

1. B 2. D 3. C 4. A 5. E

After its release, norepinephrine is broken down in the cleft and recycled via the norepinephrine transporter. Then its taken up into circulation. With recycling, small amounts are returned to vesicles. Most is metabolized by ________ ________ to dihydroxyphenylglycol, which is released into circulation. It's eventually broken down by _______, which is found in all tissues.

Monoamine Oxidase | COMT

Adrenergic receptors can be either _______ or _______.

Alpha (Alpha1 or Alpha2) | Beta (Beta1, Beta2, or Beta3)

Norepinephrine excites mainly _______ receptors but also _______ receptors to a lesser extent.

Alpha | Beta

Epinephrine excites both ______ and ______ receptors equally.

Alpha | Beta

Certain alpha receptors are ________, while others are _______.

Excitatory | Inhibitory

(ALPHA/BETA) receptors are associated with the following: - - Vasoconstriction - - Iris dilation - - Intestinal relaxation - - Intestinal sphincter contraction - - Pilomotor contraction - - Bladder sphincter contraction - - Inhibition of neurotransmitter release (alpha2)

Alpha

This type of beta receptor is associated with cardioacceleration, increased myocardial strength, and lipolysis.

Beta1

This type of beta receptor is associated with: - - Vasodilation - - Intestinal relaxation - - Uterus relaxation - - Bronchodilation - - Calorigenesis - - Glycogenolysis - - Bladder wall relaxation

Beta2

This type of beta receptor is associated with thermogenesis.

Beta3

Sympathetic preganglionic fibers are short and synapse with long postganglionic fibers via Ach and a _________ receptor. The postganglionic fibers release norepinephrine to adrenergic receptors.

Nicotinic

Parasympathetic preganglionic fibers are long and synapse with short postganglionic fibers via Ach and a ________ receptor. The postganglionic fibers release Ach to ________ receptors.

Nicotinic | Muscarinic

Muscarinic and nicotinic are both _________, however _______ deals with GPCR and ________ deals with ion channels.

Cholinergic Muscarinic Nicotinic

This drug blocks the synthesis and storage of norepinephrine.

Reserpine

This drug blocks the sympathetic beta1 and beta2 receptors.

Propranolol

This drug blocks mostly sympathetic beta1 receptors.

Metoprolol

Adrenergic beta receptor blockers ("Beta Blockers") attenuate the actions of the _________ system. They decrease heart rate and force of contraction, and are antihypertensive. 13 are commonly prescribed.

Sympathetic

_______ _______ can have the following side effects: - - Fatigue - - Hypotension - - Bradycardia - - Associated with negative changes in blood lipid profiles - - Associated with higher glucose and insulin levels

Beta blockers

______ adrenergic receptor blocker of the sympathetic system will decrease blood pressure, because these receptors normally focus on vasculature and cause the contraction of _______ _______ cells.

Alpha | Smooth muscle

This is stimulated by the sympathetic system and secretes about 80 percent epinephrine and 20 percent norepinephrine hormones. The hormones last 5-10 times longer than neurotransmitter versions because there is no local intense reuptake and destruction.

Adrenal medulla

The secretory cells of the adrenal medulla are the ________ ________. They have rudimentary fibers that secrete epinephrine and norepinephrine.

Postganglionic neurons

Note that norepinephrine/epinephrine is active for only a few seconds when secreted by neurons, but when secreted into the blood (via the adrenal medulla) it remains active until destroyed by _______ in surrounding tissues, especially the liver.

COMT

Alarm or stress response occurs when there is a mass discharge of the entire _________ system (fright, fear, severe pain): - - Increased arterial pressure - - Rerouting of blood flow to active muscles - - Increased rates in cellular metabolism - - Increased blood glucose concentration - - Increased glycolysis in liver and muscle - - Increased muscle strength - - Increased mental activity - - Increased blood coagulation rate

Sympathetic

About 75 percent of all parasympathetic fibers are in the _______ nerve.

Vagus (CN X)

T/F. Most preganglionic fibers of the parasympathetic system pass all the way to the organ that is to be innervated.

True

__________ parasympathetic fibers are located in the wall of the organ and use Ach as their neurotransmitter.

Postganglionic

Some cranial nerves carry parasympathetic signals, which are...

Oculomotor (CN III) Facial (CN VII) Glossopharyngeal (CN IX) Vagus (CN X)

The parasympathetic system has ________ nerves that pass through the spinal nerve _______ plexus on each side of S2 and S3. It supplies the colon, rectum, urinary bladder, and external genitalia.

Sacral | Sacral

Most parasympathetic nerves are __________ and synapse at the effector organ. There are very short _________ fibers.

Preganglionic | Postganglionic

The preganglionics of this cranial nerve come from the Edinger-Westphal nucleus to the ciliary ganglion, and its postganglionics go from the ciliary ganglion to the sphincter pupillae muscle.

Oculomotor nerve (CN III)

The motor function of this cranial nerve includes innervating the skeletal muscles of the eyes, including levator palpebrae superioris, superior rectus, medial rectus, inferior rectus, and inferior oblique.

Oculomotor nerve (CN III)

The parasympathetic function of this cranial nerve includes the constriction of pupillae of the iris and the ciliary muscles.

Oculomotor nerve (CN III)

The preganglionics of the cranial nerve go from the superior salivatory and lacrimal nuclei to the submandibular/sublingual ganglia. Its postganglionics go to the lacrimal gland, submandibular gland, sublingual gland, and mucous glands.

Facial nerve (CN VII)

The motor function of this cranial nerve is to provide innervation to the muscles of facial expression, as well as the muscles in the inner ear.

Facial nerve (CN VII)

The sensory innervation of this cranial nerve is to carry sensation of taste from the anterior 2/3 of the tongue.

Facial nerve (CN VII)

The parasympathetic innervation of this cranial nerve stimulates the submandibular and sublingual glands to increase the flow of saliva and stimulates the nasal mucosa.

Facial nerve (CN VII)

The preganglionics of this cranial nerve go from the inferior salivatory nucleus to the otic ganglion. The postganglionics go to the parotid gland.

Glossopharyngeal nerve (CN IX)

This cranial nerve functions to carry general sensation and sensation of taste from the posterior 1/3 of the tongue. It innervates the skeletal muscle to the stylopharyngeus muscle, and an injury to it can result in impaired swallowing.

Glossopharyngeal nerve (CN IX)

This is the longest nerve in the human body and it runs parallel to the esophagus, as well as innervates the esophagus.

Vagus nerve (CN X)

The vagus nerve passes posterior to root of lung on each side then pierces the diaphragm with the esophagus, then it becomes the _______ nerve and supplies viscera in the thoracic cavity.

Gastric

The vagus nerve does what to the heart?

Lowers heart rate

The ______ nerve does the following to the GI tract: - - Controls taste and saliva - - Increases stomach acidity (via release of histamine), digestive secretion, gut flow - - Role in controlling blood glucose balance - - Assists in releasing bile

Vagus

The vagus nerve promotes the general function and filtration of the ________.

Kidneys

For reproduction, the vagus nerve helps control ________.

Fertility

If there is a _______ nerve dysfunction, then the following can occur: - - Irritable bowel syndrome - - Anxiety - - Depression - - High or low heart rate - - Difficulty swallowing - - Esophageal reflux - - Migraines (association) - - Anxiety disorders

Vagus

________ + ________ = Acetylcholine

Acetyl-CoA | Choline

What is the enzyme used to form acetylcholine from acetyl-CoA and choline?

Choline acetyl-transferase

Acetylcholine can be broken down into _______ and _______ by the enzyme _________.

Choline Acetate ion Acetylcholinesterase

This is a poison from toadstools.

Muscarine

These receptors are found on all effector cells stimulated by postganglionic cholinergic neurons.

Muscarinic

These receptors are found in autonomic ganglia at synapses between preganglionic and postganglionic neurons. They are present in neuromuscular junctions in skeletal muscles.

Nicotinic

(MUSCARINIC/NICOTINIC) receptors have different subsets that can be stimulatory or inhibitory. They work through G-proteins.

Muscarinic

(MUSCARINIC/NICOTINIC) receptors work through ion channels.

Nicotinic

_______ _______ drugs because they bring to acetylcholine receptors (nicotinic or muscarinic).

Direct cholinergic

______ drugs inhibit cholinesterase (thus promoting acetylcholine to linger longer).

Indirect

Some chemical weapons are parasympathetic drugs such as _______ (indirect), and ______ ______.

Sarin | Tear gas

This drug is primarily used to treat glaucoma and an overdose is similar to nerve agents. It binds muscarinic and nicotinic receptors.

Carbachol

__________ drugs are not rapidly destroyed by cholinesterase. They include pilocarpine and methacholine. They act directly on muscarinic receptors.

Parasympathomimetic

Drugs that inhibit acetylcholinesterase are...

Neostigmine Pyridostigmine Ambenonium

Drugs that block cholinergic activity are...

Atropine Homatropine Scopolamine

23 - ANS Flashcards

(95 cards)