Regulate, Adjust and Coordinate vital viseral (organ) functions:

* Blood Pressure & Blood Flow

* Body Temperature

* Respiration

* Digestion

* Metabolism

* Elimination

1. Sympathetic: Maintains vital functions (responds when tehre is a critical threat to the integrity; "fight or flight response")

2. Parasympathetic: Concerned with conservation of energy; resource replenishment; maintenance of organ function during inactivity

The ANS is a motor system

It innervates (sends nerve signals to) smooth and cardiac muscles and glands.

"Fight or Flight Response"

Maintains Vital Functions in response to a critical threat

Conserving Energy

Resource Replenishment

Maintenance of Organ function during inactivity

Sympathetic: Activity;

Parasympathetic: _________

Sympathetic: Activity/Active Organs

Parasympathetic: Inactivity; resting and maintenance of organs

Sympathetic System = "Flight or Fight Response"

Increase Heart Rate & Blood Pressure

Dilate Bronchi (Lungs)

Dilate Pupils

Shunting (Moving) of blood away from the skin and viscera (organs) TO the skeletal muscles

Mobilize stored energy to provide glucose and fatty acids for the brain and skeletal muscles

During a Sympathetic Response ("Flight or Fight Response"), why does the body Increase Heart Rate & Blood Pressure?

To give energy and blood to muscles and the brain (to run away) in stressful situations and less to organs and skin

Fill in the blanks:

True or False

The Autonomic Nervous System can be controlled by the mind.

False

Autonomic = Uncontrolled by mind

Conserve energy & resources

Maintain Organ function

* Slows Heart Rate

* Increases gastric and intestinal secretion and Motility

* Empty Bladder

* Empty Bowels

* Constrict Pupils

* Contract Bronchial Smooth Muscles

The divisions of the Autonomic Nervous System, the parasympathetic and sympathetic, can work ________, ________ or ____________.

Give an Example of each.

The divisions of the Autonomic Nervous System, the parasympathetic and sympathetic, can work completementary, opposite or one at a time.

Complementary: Micturition (pass urine) and Defecation (pass stool)

Opposite: Regulation of Heart Rate

One At A Time: Regulation of Contractility of the Left Ventricle

2-Neuron Pathway

1st Neuron is called Preganglionic Neuron (cell bodies reside in brain and spinal cord and axons go into the periphery)

2nd Neuron is called Postganglionic Neuron (cell bodies are in an autonomic ganglion and axon goes out to the end organ (smooth muscle, cardiac muscle or gland)

[image]

1st Nueron in the 2-Neuron Pathway

Preganglionic Neuron:

Cell Bodies reside in Brain or Spinal Cord and Axons go Out to the Periphery

- Clusters of neuronal cell bodies and dendrites

- Part of the Postganglionic Neuron

- A junction between autonomic nerves originating from the CNS and autonomic nerves innervating their target organs in the periphery.

The 2nd Neuron in the 2-Neuron Pathway

Postganglionic Neuron:

Cell Body is an autonomic ganglion

Axon goes out to the end Organ (which can be smooth muscle, cardiac muscle or a gland)

Preganglionic Neuron:

- Cell body is in the Spinal Cord or Brain (CNS)

- Axons are myelinated

Postganglionic

- Cell body is ouside of the CNS

- Axons are unmyelinated

Part of the peripheral nervous system associated with the voluntary control of body movements through the action of skeletal muscles.

** Stimulated by external stimuli while the ANS system is an AUTONOMIC system and controls cardiac and smooth muscle involuntarily

** The somatic nervous system processes sensory information and controls all voluntary muscular systems within the body, with the exception of reflex arcs.

1. Autonomic Nervous System (automatically controls cardiac (heart) and smooth (ex: Intestines) muscles and visceral organs

2. Somatic Nervous System (voluntarily controls skeletal muscle movements and organs)

Comparison of Somatic Nervous System with Autonomic Nervous System.

Fill in the blanks.

Organs or molecules that become active upon nerve stimulation

Dictionary.com:

A bodily organ (as a gland or muscle) that becomes active in response to stimulation

A molecule (as an inducer, a corepressor, or an enzyme) that activates, controls, or inactivates a process or action (as proteinsynthesis or the release of a second messenger)

Autonomic Nervous System:

2-Neuron Pathway

Somatic Nervous System:

1-Neuron Pathway

Parasympathetic Nervous System Receptors

CNS > Preganglionic Nueron >

___(receptor?)__ > Postganglionic Neuron > ___(receptor?)__ > Various Organs

CNS > Preganglionic Nueron >

Acetycholine > Postganglionic Neuron > Acetycholine > Various Organs

Sympathetic Nervous System Receptors

CNS > Preganglionic Neuron >

___(receptor?)__ > Postganglionic Neuron > ___(receptor?)__ > Various Organs

CNS > Preganglionic Neuron >

Acetylcholine > Postganglionic Neuron > Neurepinephrine > Various Organs

Sympathetic Nervous System Receptors

CNS > Preganglionic Neuron >

___(receptor?)__ > Postganglionic Neuron > ___(receptor?)__ > Sweat Glands

CNS > Preganglionic Neuron >

Acetylcholine > Postganglionic Neuron > Acetylcholine > Sweat Glands

Sympathetic Nervous System Receptors

CNS > Preganglionic Neuron >

___(receptor?)__ > Adrenal Medulla >

___(receptor?)__ > Various Organs

CNS > Preganglionic Neuron >

Acetylcholine > Adrenal Medulla >

Epinephrine > Various Organs

Somatic Motor System Receptors

CNS > Motor Neuron >

___(receptor?)__ > Skeletal Muscles

Fill in the Blanks

Comparison of Somatic and Automic

The neurotransmitter in the postganglionic neuron for the sympathetic nervous system to various organs is Norepinephrine.

CNS > Preganglionic Neuron > Acetycholine > Postganglionic Neuron > Norepinephrine > Various Organs

The receptors on the organs can be ________ or _________.

The receptors on the organs

can be alpha or beta.

Acetylcholine is the neurotransmitter for preganglionic neurons for both ANS divisions (Parasympathetic and Sympathetic).

The Receptor for the preganglionic neurons of both Parasympathetic an Sympathetic is ________________.

Acetylcholine is the neurotransmitter for Postganglionic neurons for the Parasympathetic Division.

The Receptor for the Postganglionic neurons of the Parasympathetic Division is ________________.

Sympathetic Nervous System

Fill in the blanks.

1. CNS

2. Preganglionic Neuron

3. _? Neurotransmitter__

4. _? Receptor_

5. Postganglionic Neuron
6. __? Neurotransmitter__

7. __? Receptor__

8. Various Organs

Sympathetic Nervous System

1. CNS

2. Preganglionic Neuron

3. Acetylcholine

4. Nicotonic Postganglionic Acetylcholine Receptor

5. Postganglionic Neuron
6. Norepinephrine

7. Alpha OR Beta Receptors

8. Various Organs

Parasympathetic Nervous System

Fill in the blanks.

1. CNS

2. Preganglionic Neuron

3. _? Neurotransmitter__

4. _? Receptor_

5. Postganglionic Neuron
6. __? Neurotransmitter__

7. __? Receptor__

8. Various Organs

Parasympathetic Nervous System

1. CNS

2. Preganglionic Neuron

3. Acetycholine

4. Nicotinic Postganglionic Acetylcholine Receptor

5. Postganglionic Neuron
6. Acetylcholine

7. Muscuranic Receptor

8. Various Organs

Axons exit the spinal cord at each level and immediately synapse at a paraspinal sympathetic ganglion.

The paraspinal sympathetic ganlion are interconnected (Connect together) so that unitary or whole activation of the sympathetic nervous system is possible.

Preganglionic nerve cell bodiesa re in the the throaco/lumbar cord from T1 to L2.

Axons eit the spinal cord at each level and immediately synpase with paraspinal sympathetic ganglion.

The sympathetic ganlia are interconnect (connected), making unitary or whole activation of the sympathetic nervous system possible.

Explain the pathway the Sympathetic Neurons take to activate the Sympathetic System and reach their ending organ targets.

(This is heavy flashcard

Its combining Slides 8-10)

Step 1: Signals are sent from the CNS (Brain and/or spinal cord)

Step 2: Preganglionic nerve cell bodies are in the thoraco/lumbar cord from T1 to L2.

Step 3: Axons exit the spinal cord at each level and immediatly synapse (connect) with a paraspinal sympathetic ganglion.

(To incorporate, the axons leave the spinal cord at each level, release the neurotransmitter acetylcholine, synpase (connect) with the nicontinic postganglinoic acetylcholine receptor on the paraspinal sympathetic ganglion.)

Step 4: The Sympathetic System becomes activated because the paraspinal sympathetic ganglion are intertwined/interconnected, making unitary (whole) activation of the Sympathetic System possible.

Step 5: Axons of the postganglionic sympathetic neurons leave the paraspinal ganglion and innervate (send nerve singals to) smooth & cardiac muscle and glands

(To Incorporate: Axons of the postganglionic sympathetic neurons leave the paraspinal ganglion, release neurotransmitter (either norepinephrine or acetylcholine), attach to their receptor (either Alpha, Beta or Nicotinic Receptors) to activate smooth & cardiac muscle and glands.)

Sympathetic Pathway: Adrenal Medulla

Preganglionic axons from the sympathetic centers in the ___________ cord go directly to the adrenal medulla where they innervate (send never signals to) cells called ____________.

Mostly epinephrine

Sometimes Norepinephrine

* Both of these products are secreted into the bloodstream, rather than being released into the synapse

Epinephrine is secreted into the bloodstream and activates beta-2 receptors that are not innervated by the SNS.

*Epinephrine can also activate Beta-1 and Alpha receptors, however, they are more likely to be activtated by norepinephrine that is released from postganglionic axon terminals into their synapses at the end of organs in the SNS.)

Remember: CNS > Preganglionic Axon > Acetylcholine > Nicotinic Receptor > Postganglionic Neuron > Norepinephrine > Alpha and Beta Recetors

1. Preganglionic Cells in the thoracocolumbar cord go directly to the Adrenal Medulla, which is a gland that sits on top of the kidneys.

2. The preganglionic axons innervate (signals) enterochromaffin cells.

3. Enterochromaffin cells synthsize epinephrine (and small amounts of Norepinephrine).

4. Epinephrine (and norepinephrine) are secreted (released) into the bloodstream

5. While circulating in the blood, epinephrine activates Beta-2 Receptors.

1. Brain Stem

2. Sacral Cord

CN III - Oculomotor (Dilate Pupils)

CN VII - Facial (Salivary, nasal and lacriminal glands)

CN IX - Glossopharyngeal (Salivary Glands)

CN X - Vagus Nerve (most important)

Parasympathetic System

Preganglionic axons in the vagus nerve supply what organs?

Mainly: Heart, Trachea, Lungs, Esophagus, Stomach, Small Intestines

Some of the: Colon, Liver, Gallbladder, Pancreas, Kidneys and Upper Uterers

The parasympathetic System supplies preganglionic axons for the cranial nerves in the Brainstem (CN III, VII, CN IX, X).

The Cranial Nerves are separated by what?

Do they act independently or dependently?

Can they communicate with each other?

The parasympathetic centers in the brain that supply the various cranial nerves are separated by distance and function.

There may be communication between the nerves, but they act independently

S2-S4

Sacral 2 -Sacral 4 levels

Where they go to the bladder, uterus, urethra, prostate, distal colon, rectum and vasculature of the genitalia.

The sacral and cranial parts of the parasympathetic system are

A. Independent of each other

B. Dependent on each other

The sacral and cranial parts of the parasympathetic system are independent of each other.

This is different from the sympathetic system, which is an interconnected sympathetic chain.

Parasympathetic: Once the preganglionic axons leave the spinal cord, they still act independent of each other.

Sympathetic: Once the preganglionic axons leave the spinal cord, they interconnect and work together as unit at the same time.

1. Begins with cranial nerves in the brain stem.

2. Preganglionic axons attached to the cranial nerves go down the spinal cord and exit through S2-S4 (Sacral 2 - 4)

3. Preganglionic axons release the neurontransmitter acetylcholine to activate nicotinic Receptors.

4. Postganglionic neurons fire and release acetylcholine to activate muscuranic receptors on the end organ's individual cells.

Parasympathetic Nervous System:

1. Acetylcholine > Nicotinic Receptors

2. Acetylcholine > Muscurarinc Receptors

Sympathetic Nervous System:

1. Acetylcholine > Nicotinic Receptors

2. Epineprine > Alpha Beta Receptors > Organs

or

2. Acetylcholine > Muscuranic Receptors > Sweat Glands

or

2. Adrenal Medulla > Enterochromaffin Cells Circulate in Blood Stream > Mostly Beta-2 Receptors, some Beta-1 and Alpha Receptors

Comparison of the SNS and PNS.

Fill in the Chart.

The adrenergic receptors (or adrenoceptors) are a class of G Protein Coupled Receptors that are targets norepinephrine & epinephrine.

Many cells posses these receptors and will cause a sympathetic (fight or Flight) response when an angonist binds to the adrenergic Receptors

Adrenergic Receptor Subtypes

Where are Alpha-1 Receptors? What response do they produce?

Alpha-1 Receptors

Arteries & Veins > Constriction

Bladder neck > Constriction

Adrenergic Receptor Subtypes

Where are Alpha-2 Receptors? What response do they produce?

 Alpha-2 Receptors

Central Nervous System > Inhibits Sympathetic Outflow

Adrenergic Receptor Subtypes

Where are Beta-1 Receptors? What response do they produce?

 Beta-1 Receptors

Heart, SA Node: Increase heart rate

Heart, AV Node: Increases speed of conduction

Heart, Ventricular Muscle: Increased Contractibility

Kidney: Release of Renin (causes arterial constriction)

Adrenergic Receptor Subtypes

Where are Beta-2 Receptors? What response do they produce?

Beta-2 Receptors:

Arterioles in skeletal Muscle Beds: Dilate

Bronchi: Dilate

Uterus: Relax

Memorize:

Which of the following is a result of SNS stimulation?

A. Slowing of heart rate

B. Increased gastric and intestinal secretion and motility

C. Constriction of the Pupil

D. Dilation of Bronchi

Which of the following is a true statement?

A. The structure of the ANS is a one-neuron Pathway.

B. The ANS is a motor response.

C. The SNS is concerned with conservation of energy

D. The PNS responds when thre is a critical threat to the integrity of the organism

A. The structure of the ANS is a one-neuron Pathway. - Wrong - 2-Neuron Pathway

B. The ANS is a motor response. - Correct

C. The SNS is concerned with conservation of energy - Wrong - Parasympathetic is concerned with conserving energy

D. The PNS responds when thre is a critical threat to the integrity of the organism - Wrong - Sympathetic Nervous system responds to critical threats to the body

Alpha-1 Agonist drugs are used as pressors (raise blood pressure) or decongest.

3 Drugs that are Alpha-1 Agonists

Phenylephrine (Neo-Synephrine)

Oxymetazoline (Afrin)

Pseudoephedrine (Sudafed)

3 Drugs that are Alpha-1 Agonists

Phenylephrine (Neo-Synephrine)

Oxymetazoline (Afrin)

Pseudoephedrine (Sudafed)

Alpha-1 Antagonist drugs are used for hypertension and for urinary retention in benighn prostatic hypertrophy

* Remember Antagonist PROHIBIT the receptors from acting. Alpha 1 Receptors constrict blood vessels and the bladder neck. By blocking the Alpha-1 Receptors, blood vessels will not constrict as much causing blood pressure in hypertension patients to decrease & the bladder will not be constricted so it will open the bladder neck so urine retention will not occur.

Alpha-1 Antagonist Drugs

Prazosin

Terazosin

Doxazosin

Alpha-1 Antagonist Drugs

Prazosin

Terazosin

Doxazosin

Blocked Alpha-1 Receptors (which constrict arteries), cause arteries to become dilated and reduces Blood Pressure directly

Alpha-1 Receptors, which constrict veins, become dilated by alpha-1 antagonists and reduces venous return to the heart, which reduces cardiac output, which reduces blood pressure

What happens to the uretha in a patient with benighn prostatic hypertrophy?

How does an Alpha-1 Antagonist help patients urinate easier?

As the prostate enlarges, it compresses the uretha, making it difficult to urinate.

Blocking the Alpha-1 Receptor with an Alpha-1 Antagonist, reduces contraction of smooth muscles in the bladder neck, making urination easier

(* Note: Alpha-1 receptors cause the bladder neck to constrict. By blocking the alpha-1 receptors, the bladder neck can dilate, making urination easier)

Catecholamine: Fight or Flight hormone released by the adrenal gland

The hormones released are usually Epinephrine & Norepinephrine

Pheochromocytoma: A catecholamine (Fight or Flight hormone (usually epinephrine or norepinephrine) released by the adrenal gland) secreting tumor derived from the medulla

A phaeochromocytoma (PCC) or pheochromocytoma, is a neuroendocrine tumor of the medulla of the adrenal glands (originating in the enterochromaffin cells), or extra-adrenal chromaffin tissue that failed to involute after birth. It secretes excessive amounts of catecholamines (norepinephrine or epinephrine,.

1. Orthostatic Hypotension

2. Reflex tachycardia

3. Nasal Congestion

4. Inhibition of Ejaculation

When a person stands up, their sympathetic nervous system is activated and their alpha-1 receptors are stimulated with norepinephrine.

Norephinephrine (an alpha-1 receptor) constrict arteries and veins to increase venous return to the heart and arterial blood pressure and to allow them to maintain full blood flow to the brain

When Alpha-1 Receptors are blocked, this activity does not occur and the person may feel dizzy or faint when standing up

Blood pressure drops because of the Alpha-1 Blockade (Antagonist) inhibits vein and artery constrictions.

When this happens, the baroreceptor reflex is activated to raise blood pressure back up. (* Note: Baroreceptors are in the arteries that communicate with the CNS and tell them to increase or decrease cardiac output)

This causes sympathetic tone (activation of the fight or flight response), however, arterioles and veins cannot constrict because of the alpha-1 blockade

Beta receptors (receptors in charge of heard rate, conductibility and speed of conduction), however, can be activated, causing tachycardia. This can be prevented by giving a beta blocker with the alpha blocker.

Sensors located in the blood vessels of the body.

They detect blood flow and communicate with the CNS to increase or decrease cardiac output

Beta-1 Agonist drugs: Increase Heart Rate & Strengthen Contraction

Beta-1 Agonist drugs

Isoproterenol

Dobutamine

Beta 2 Agonists: Dilate Bronchioles or to Stop preterm labor

Beta-2 Agonist Drugs

Terbutaline

Ritodrine

Albuterol

Beta-1 specific are cardioselective.

Their selectivity is not absolute and they may cause bronchospasm in some individuals.

Beta-1 Specific Drug:

Metoprolol

Block both Beta 1 (heart receptors) and Beta 2 (Lung) receptors

However, they are more likely to cause bronchospasms than cardiovascular beta-1 specific antagonists

Nonspecific Beta Blocker Drugs:

Propanolol

Mixed alpha/beta antagonists are used for hypertension and heart failure

Combined Alpha/Beta Blockers:

Labetolol

Carvedilol

Beta-1 Blockers

Reduced heart rate

Reduced speed of conduction of the AV Node

Reduced Ventricular Contractibility

Reduce Renin release from the kidney (regulates blood pressure)

Beta-2 Blockers

Bronchoconstriction

* Worsen/exacerbate heart failure

* Cause heart block (disease of the electrical system of the heart)

* Cause symptomatic bradycardia (decreased Heart Rate)

* Lower Blood pressure because of less angiotensin II

* Lessens Aldosterone release due to less angiotensin II

RAAS Summary:

When blood volume is low, the kidneys secrete renin. Renin stimulates the production of angiotensin, which causes blood vessels to constrict resulting in increased blood pressure.

Renin stimulates the production of angiotensin, which also stimulates the secretion of the hormone aldosterone from the adrenal cortex. Aldosterone causes the tubules of the kidneys to increase the reabsorption of sodium and water. This increases the volume of fluid in the body, which also increases blood pressure.

Angina: Decrease the workload of the heart by lowering HR and contractability

Hypertension: Reduces peripheral vascular resistance

Cardiac Dysrrhythmias (irregular heart beat): Prevent sudden death in Post-MI patients

Myocardial Infarction (Heart Attack): Reduce infarct (reduce tissue death) size and reduce risk of 2nd heart attack

Stage Fright: Prevents tremulousness (involuntary movements)

Glaucoma: Topically