Autonomous Nervous System

Question 1

What is the Nervous system

Answer 1

• brain
• spinal cord (central NS)
• nerves (peripheral nervous system)

Question 2

function of the nerves

Answer 2

• transport sensory information to the brain
• transport motor information to muscles to produce the response

Question 3

what is the autonomous nervous system?

Answer 3

the unconscious part of the nervous system

• it also receives sensory inputs, interprets them, produces motor outputs, but for all the day to day regulatory tasks that you don’t have to think about or be aware

Question 4

What is a neuron

Answer 4

the main cell type of the central and peripheral nervous system

Question 5

how is called the information that travels in neuron

Answer 5

elctrical signals called action potentials

Question 6

how can neurones communicate across synapses

Answer 6

neurotransmitters

Question 7

how can the speed of information conduction between neurons can be increased?

Answer 7

myelin sheath

Question 8

2 divisions of the ANS

Answer 8

• sympathetic and parasympathetic systems

Question 9

4 parts of the spinal chord

Answer 9

• thoracic
• lumbar
• sacral
• cervical

Question 10

Entry/exit of axons to CNS for each ANS division - and their main function

Answer 10

Question 11

Question you can ask in history to assess the ANS

Answer 11

Decreased sweating (fever, exercise, heat)

Dry mouth

Constipation / abdominal fullness

Postural dizziness (dizzy when standing up)

Bladder dysfunction (difficulty urinating or excessive urination)

Sexual dysfunction / inability to have an erection

Question 12

what is an adrenergic receptor

Answer 12

receptors for catecholamine (nora and adrénaline)

Question 13

name of the acetylcholine receptor

Answer 13

Muscarinic or nicotinic = cholinergic receptors

Question 14

what kind of medication can promote or block specific autonomous function?

Answer 14

agonist = promote
antagonist = block

Question 15

what is a non-selective medication

Answer 15

if it acts on all the receptors of a family (e.g. all beta receptors)
selective: only beta1 agonist

Question 16

constriction of the bronchi (airways) are caused by..

and smooth muscle relaxaion of the airways?

Answer 16

cholinergic receptors (parasympathetic)

beta-adrenergic receptors (sympathetic)

Question 17

Post-ganglionic receptors of the sympathetic system

Answer 17

adrenergic

Question 18

post-ganglionic receptors of parasympathetic system

Answer 18

cholinergic

Question 19

What structures have only sympathetic innervation?

Answer 19

Systemic arteries, sweat glands, and the bladder sphincter

The parasympathetic and sympathetic divisions usually have opposing functions. These are exceptions.

Question 20

fight or flight response (sympathetic NS)

Answer 20

Sympathetic effects:
- increased rate and force of cardiac muscle
- blood flow is diverted to skeletal muscle
- bronchial smooth muscle is relaxed
- brings more oxygen to the muscles
- decreased blood flow through skin and visceral organs
- activity of the gastro‑intestinal tract is reduced and sphincters contracted
- pupils are dilated
- glycogenolysis and lipolysis mobilize energy stores

Question 21

summarize the functions of the parasympathetic nervous system

Answer 21

SLUDD

• salivation,
• lacrimation,
• urination,
  -digestion and
  -defecation

Question 22

which receptors are present on ganglia

Answer 22

nAChR = nicotinic acetylcholine receptors

Question 23

where are the muscarinic ACh receptors?

Answer 23

mostly parasympathetic (cardia and smooth muscle, gland cells, nerve terminals)

Question 24

when are norepinephrine or epinephrine hormones or neurotransmitters

Answer 24

Norepinephrine released from sympathetic nerve terminals acts as a neurotransmitter.

Epinephrine and norepinephrine, released from the adrenal glands into the blood, act as hormones.

Question 25

where are the cholinergic synaptic junctions

Answer 25

all ANS ganglia, parasympathetic end organs and sympathetic (sweat glands only)

Question 26

4 ways therapeutic drugs can increase or decrease the amount of acetylcholine that goes from persynaptic to post-synaptic

Answer 26

1. act on presynaptic receptors (feedback control of acetycholine release)
2. act on post-synaptic receptors (antagonist would bloc those receptors if we needed to decrease the amount of ACh)
3. inhibit or sitmulate the action of acetylcholinesterase (that degrades de ACh in synapse)
4. inhibit ACh release

Question 27

Which are faster, nicotinic or muscarinic receptors?

Answer 27

nicotinic

Question 28

what is a GPCR

Answer 28

G-protein coupled receptors

A typical GPCR gives rise to multiple intracellular signalling cascades. Generally, GPCRs signal in a slower fashion than ligand-gated ion channels such as nicotinic receptors. = muscarinic AChRs are GPCRs

Question 29

one of the most important role of parasympathetic nervous system

Answer 29

slow the heart rate by acting on the cardiac pacemaker

Question 30

In what kind of recepto calss do adrenoceptors are part?

Answer 30

muscarinic

Question 31

many ways drug can act to stimulate or inibate the transmission of NE

Answer 31

• transmitter synthesis
• transmitter storage
• transmitter release
• pre or post synaptic receptors
• transmitter reuptake
• enzymatic inactivation

Question 32

What happens if we inhibit transmitter reuptake of NE

Answer 32

excessive synaptic NE incrases bP and can cause stroke (cocaine)

Question 33

how do you call receptors for epi and NE ?

Answer 33

adrenergic receptors and adrenoceptors

Question 34

You can use drugs to stimulate postsynaptic adrenoceptors in two ways:

Answer 34

(1) Indirectly, by increasing transmitter release. Some nasal decongestants and amphetamine: we call these indirect agonists (see later).

(2) Agonist acting directly on receptors in order to mimic NE.

Question 35

Is stimulating of blocking ganglionic nicotinic AChRs is therapeutically useful?

Answer 35

nop. better act on post ganglia receptors

Question 36

How can muscarinic receptor activation cause vasodilation?

Answer 36

Muscarinic receptor activation increases release of nitric oxide (side note: nitric oxide = NO is also known as EDRF), which in turn activates intracellular guanylyl cyclase, leading to increases in intracellular cGMP levels, leading to smooth muscle relaxation and hence vasodilation.