Autonomic Nervous System

Question 1

What’s the Basic Function of the Nervous System?

Answer 1

Voluntary motor function (skeletal muscle)

Sensory Input

Automatic Response

Question 2

What does the Central Nervous System include

Answer 2

Brain and spinal cord

Question 3

What does the brain stem house and what does it control?

Answer 3

Brain stems includes clusters of cells that control respiration, cardiac, vascular function, digestive functions

Reticular activating system runs through brain stem (alertness and attention)

sleep functions

Question 4

What does the spinal cord consist of?

Answer 4

White matter: bundles of nerve fibers with similar function (some afferent and some efferent)

Gray Matter: butterfly shape surrounded by white matter and is neuron cell bodies and glial cells

Question 5

Ventral/Dorsal/Lateral Horn functions:

Answer 5

Ventral horn: contains cell bodies of somatic efferent motor neurons supplying skeletal muscles

Dorsal Horn: cell bodies of interneurons/ afferent sensory neurons terminate

Lateral Horn: ANS nerve fibers supplying cardiac and smooth muscle, and endrocine glands originate in cell bodies here

Question 6

What is included within the Peripheral Nervous System of CNS:

Answer 6

Cranial and Spinal Nerves

Question 7

What do the Cranial Innervate? (Peripheral NS)

Answer 7

12 paired nerves that branch off brainstem

Mainly innervate head and neck regions with the exception of the vagus nerve (GI)

Question 8

What do the spinal nerves innervate? (Peripheral NS)

Answer 8

Paired nerves branching off of spinal cord and innervating post cranial body (skin, muscle, organs…)

8 C, 12 T, 5 L, 5 S, 1 C

Question 9

Spinal Nerves:

Answer 9

Sensory information comes into spinal cord through neurons in the dorsal root (houses sensory afferent)

Motor (efferent) neurons leave the spinal cord through ventral root (carrying signals to body)

Question 10

Afferent Sensory Neurons sense what?

Answer 10

mechanoreceptors= positional sensation, touch, vibration

Nociceptors= pain

Thermoreceptors

Question 11

What does the ANS Innervate and what do SNS and PNS do within the ANS system?

Answer 11

ANS: Efferent neurons that carry out specific function and target smooth/ cardiac muscles and glands

SNS: maintains metabolic homeostasis and increases overall activity in response to increased demand

PNS: Produces more targeted responses to facilitate digestion, repair and resting functions to allow body to maintain energy stores/recover

Question 12

Where does Sympathetic Nervous System start?

Answer 12

Begins in the central portion of the spinal cord

Preganglionic neuron extends a shorter distance than the postganglionic

Question 13

Where does Parasympathetic Nervous System start?

Answer 13

PNS begins in the brain stem or in the sacral region

Preganglionic neuron extends longer distance than the postganglionic neuron

Question 14

All autonomic nerves leaving the spinal cord are what?
What is the neurotransmitter released?

Answer 14

Cholinergic

Acetylcholine: signals the first synapse outside the spinal cord for both SNS and PNS

Question 15

What’s the difference between PNS and SNS neurons?

Answer 15

Postganglionic synapses of PNS is cholinergic
Postganglionic synapses of SNS is adrenergic

Question 16

What Neurotransmitter is released at SNS motor neurons and as a hormone by the adrenal medulla?

Answer 16

Norepinephrine (catecholamines)

Question 17

Primary neurotransmitters for postganglionic SNS (adrenergic) responses?

Answer 17

NE (also epinephrine and dopamine)

Question 18

What destroys NE at the synaptic cleft?

Answer 18

Catecholamine-o-methyl transferase

Can reauptake

If reuptake, NE can be reused or destroyed by an enzyme called monoamine oxidase

Question 19

What destroys NE at the synaptic cleft?

Answer 19

Catecholamine-o-methyl transferase

Can reauptake

If reuptake, NE can be reused or destroyed by an enzyme called monoamine oxidase

Question 20

Alpha 1 Receptor Location and response:

Answer 20

EXCITATORY- Dilation of pupils

sympathetic target tissue (includes major arteries, arterioles of GI, arterioles of skin)

Question 21

Alpha 2 Receptor Location/Response:

Answer 21

INHIBITORY-Inhibit release of norepinephrine (dilator)

Mainly on Digestive organs- Decreases smooth muscle contraction in GI tract

Question 22

Beta 1 Receptors Location/Response:

Answer 22

Excitatory- Increase heart rate and force of contraction

SA/AV Nodes of heart, ventricular myocardium, kidneys

Question 23

Beta 2 Receptors Location/Response:

Answer 23

INHIBITORY-arteriolar or bronchiolar dilation

Smooth muscles of arterioles or bronchioles

Question 24

Primary neurotransmitter in Parasympathetic system and what metabolizes it?

Answer 24

Acetylcholine
Acetylcholinesterase (metabolizes)

Question 25

Cell receptors that initiate parasympathetic responses are called?

Answer 25

cholinergic receptors (2 types muscarinic and nicotinic)

Question 26

Where are (cholinergic) nicotinic receptors located and response?

Answer 26

Nicotinic:
-Primary location is in ganglionic synapse of both PNS and SNS
-Stimulation of smooth/skeletal muscle and gland secretions
Muscarinic:
-Located on PNS organs (smooth muscle/ cardiac muscle/gland)
-Stimulation of smooth muscle and gland secretions
-Decrease hear rate/contraction

Question 27

What are SNS adrenergic receptors called:

Answer 27

a1, b1, a2, b2, b3

Question 28

SNS and PNS action on the eye:

Answer 28

PNS: stimulation constricts the pupil and drain fluid chambers
SNS: increased fluid production and dilating pupils

Question 29

B2 and M receptors on the lungs do what?

Answer 29

Beta 2 when stimulated by NE/adrenergic agonists bronchodilate and decrease airway secretions

M when stimulated by Ach/cholinergic agonist drugs will bronchoconstrict and increase secretion

Question 30

Heart receptors and action:

Answer 30

B1 receptors stimulation from NE/ adrenergic agonists increase heart rate, contractility, AV Nodal conduction and cardiac output

Muscarinic receptors stimulation from Ach/cholinergic agonist decrease SA nodal firing and decrease AV node conduction decreases

Question 31

Sympathomimetics:

Answer 31

drugs that mimic action of NE are adrenergic drugs (sympathomimetics)

Adrenergic agonists initiate similar response to catecholamines such as NE

Directed-Indirect (Stimulates release of NE)-mixed/acting (both)

Question 32

Sympatholytic Drugs:

Answer 32

Drugs that block effects of catecholamines such as NE are adrenergic antagonists (prevent response)

Question 33

Parasympathomimetics:

Answer 33

stimulate cholinergic receptors of PNS
Direct-Indirect Iinhibit enzyme that destroys Ach)

Question 34

Parasympatholytics:

Answer 34

Drugs that block effects of Ach are cholinergic blockers or anti-chol.
Major responses:
-Decreased GI motility, decrease in saliva, dilation of pupils