Autonomic Nervous System

Autonomic Nervous System, Cholinergic and Adrenergic receptors

Parasympathetics and sympathetics make up what nervous system?

Autonomic

The brain and spinal cord make up what nervous system?

Central

The autonomic and somatic nervous systems make up what greater nervous system?

Peripheral

Thoracolumbar nerves that exit from the thoracic and lumbar regions are what kind of nerves?

Sympathetic

Craniosacral nerves that exit from the cranial and sacral regions are what kind of nerves?

Parasympathetics

Nerve fibers from the somatic nervous system only innervate what?

Striated skeletal muscle

Which nervous system contains nerve fibers that have ganglion?

Autonomic

Which nervous system contains nerve fibers that have no ganglion?

Somatic

Nerve fibers from the Autonomic nervous system innervate what?

Smooth muscle, cardiac muscle, and glands

How do you determine whether a nerve fiber is sympathetic or parasympathetic?

By looking at the region its axons (preganglionic fibers) leave

What is the area where axons meet called?

Ganglion

What nervous system (autonomic or somatic) contains a 2 nerve network with ganglion?

Autonomic

True or false: majority of organs have dual innervations (PNS and SNS)

True

What are compounds released from nerves that work locally?

Neurotransmitters

What are compounds released from a gland that works in the blood to initiate a response somewhere else?

Hormones

What are the neurotransmitters of the autonomic nervous system?

Acetylcholine (ACh) and Norepinephrine (NE)

Describe a Cholinergic nerve

A nerve that releases acetylcholine (ACh) that then works on a Cholinergic receptor

What are the two kinds of Cholinergic receptors?

Nicotinic and Muscarinic

What neurotransmitter has a very high affinity (is a full agonist) and is nonselective for both nicotinic and muscarinic receptors?

Acetylcholine (ACh)

What kind of receptors does skeletal muscle contain?

Nicotinic

What neurotransmitter has affinity to alpha 1, alpha 2, and beta 1 receptors?

Norepinephrine (NE)

What nerve releases Norepinephrine (NE)?

Adrenergic

True or false: Norepinephrine (NE) has affinity for nicotinic and muscarinic receptors

False

True or false: Acetylcholine (ACh) has no affinity for alpha and beta receptors

True

Blood vessels, arteries, and veins only receive innervation from what nervous system?

Sympathetic

What is the space in between the nerve terminal and cell body called?

Synapse

When nicotine binds to nicotinic receptors, you can have muscle contractions due to what?

Nicotine mimicking ACh

Where are Muscarinic receptors located?

In organs all over the body

Where is Norepinephrine (NE) predominantly released from?

Postganglionic sympathetic fibers

What receptors does Norepinephrine (NE) bind to in the heart?

Beta 1

What receptors does Norepinephrine (NE) bind to in blood vessels?

Alpha 1

What is the gland that synthesizes Epinephrine termed?

Adrenal medulla

If your sympathetics increase, release of what neurotransmitter subsequently increases?

Epinephrine

What occurs at the adrenal gland (medulla) to release Epinephrine?

Acetylcholine (ACh) binds to the adrenal gland’s nicotinic receptor, stimulating Epinephrine release

Sweat glands contain what kind of receptor that Acetylcholine binds to?

Muscarinic

Epinephrine (EPI) is similar to Norepinephrine (NE) in that it binds to Alpha 1, Alpha 2, and Beta 1. What other receptor does Epinephrine (EPI) bind to that makes it different?

Beta 2

What two neurotransmitters bind Adrenergic receptors?

Epinephrine (EPI) and Norepinephrine (NE)

Autonomic nervous system innervates all organs/glands except for what?

Skeletal muscle

Denervation within the somatic nervous system results in what?

Paralysis and atrophy

Conservation of energy, bradycardia, vasodilation, reduced blood pressure, increased renal blood flow, increased urine output, increased GI motility, and reduced respirations are all functions of what nervous system?

Parasympathetic

Expenditure of energy, tachycardia, vasoconstriction, increase blood pressure, decreased renal blood flow, decreased urine output, increased respirations, and reduced GI motility are all functions of what nervous system?

Sympathetic

What muscles is the Sinoatrial (SA) node responsible for that ultimately determines heart rate?

Cardiac myocytes

Within the parasympathetic nervous system’s nerve terminal, vesicles are filled with thousands of neurotransmitters like ACh. When the action potential reaches the synapse, these are released into the synapse, allowing ACh to diffuse across the synapse and bind to a __________ receptor that decreases calcium, leading to a decrease in heart rate.

muscarinic

Within the sympathetic nervous system’s nerve terminal, vesicles are filled with thousands of neurotransmitters like NE. When an action potential stimulates the release of NE into the synapse, what receptor does NE bind to that increases calcium, resulting in an increased heart rate?

Beta 1

What receptors, when stimulated, are responsible for an increase in heart rate?

Beta 1

What receptors, when stimulated, are responsible for a decrease in heart rate?

Muscarinic

What term is used to describe pupil dilation?

Mydriasis

What term is used to describe pupil contraction?

Miosis

The Iris sphincter muscle is controlled by the PNS and causes Miosis when stimulated. What receptors are responsible for causing this contraction?

Muscarinic

The Iris radial muscle is controlled by the SNS and causes Mydriasis when stimulated. It does this through contraction, however the contraction is in an outward direction, actually causing dilation. What receptors are responsible for causing, ultimately, dilation of the pupil?

Alpha 1

What are the 5 key steps in neurotransmission?

Synthesis, storage, release, recognition, and metabolism

ACh is predominantly metabolized postsynaptically by what enzyme?

Acetylcholinesterase (AChE)

What would be the effect of blocking AChE?

Less ACh is cleaved by the enzyme, allowing more ACh to bind to receptors

NE is primarily cleared from the synaptic space by presynaptic reuptake into the nerve terminals via what?

Norepinephrine Transporter (NET)

What effect would occur if NET was blocked?

More NE is available to bind to alpha/beta receptors

What is the effect of stimulating nicotinic receptors in a postganglionic autonomic cell body?

Action potential

What is the effect of stimulating nicotinic receptors in the adrenal gland?

Secretion of Epinephrine (EPI)

What is the effect of stimulating nicotinic receptors at the neuromuscular junction (NMJ)?

Skeletal muscle contractions

What is the effect of stimulating muscarinic receptors?

Parasympathetic associated responses (SLUDE) like bradycardia, airway contraction, increased urination, increased GI motility, vasodilation, miosis, increased salivation, tears, and sweating, etc.

What would be the response of your airways if Muscarinic receptors were inhibited?

Airways relax allowing you to breathe in more air

What is the effect on vasculature when Muscarinic receptors are activated?

Relaxes the smooth muscle on the walls of the vasculature through generating nitric oxide (NO), resulting in vasodilation

What is the effect of stimulating Adrenergic receptors?

Sympathetic nervous system responses like tachycardia, bronchorelaxation, decreased urination and GI motility, mydriasis, etc.

What receptor is responsible for tachycardia in the heart?

Beta 1

What receptors are responsible for bronchorelaxation, decreased urination, and decreased GI motility?

Beta 2

What receptor is responsible for mydriasis?

Alpha 1

What receptor is responsible for increased contractile force and heart rate?

Beta 1

What receptor is responsible for vasodilation and lower total peripheral resistance?

Beta 2

What receptors are responsible for vasoconstriction and increased total peripheral resistance?

Alpha 1 and Alpha 2

In most cases, what nervous system predominates?

Parasympathetic

An exception to dual innervation, what innervation do blood vessels receive?

Sympathetic

An exception to dual innervation, what innervation do sweat glands receive?

Sympathetic cholinergic

An exception to dual innervation, what innervation do bronchioles receive?

Parasympathetic