F3. Autonomic Nervous System

Question 1

what does the central nervous system include?

Answer 1

brain and spinalcord

Question 2

sensory nerves?

Answer 2

travel to the spinal cord from periphery (e.g. skin) - afferent fibres

Question 3

motor nerves?

Answer 3

travel away from the spinal cord to the muscle: somatic efferent system. Voluntary control of skeletal muscle

Question 4

autonomic nerves?

Answer 4

– unconscious physiological control of organ systems

Question 5

drug targets of CNS?

Answer 5

Drugs for CNS disorders, pain relief

Question 6

Drug targets for peripheral nervous sytem?

Answer 6

sensory nerves- pain relief, local anaesthetics
motor nerves- Muscle weakness (myasthenia gravis) Muscle paralysis during operations
autonomic system- Many common drugs
Cardiovascular, GI, respiratory, urinary tract, OTCs

Question 7

Divisions of the autonomic system?

Answer 7

sympatheic nervous system (prepares for activity), parasympathatic nervous system (stimulates visceral processes). They usually work together, not opposing actions

Question 8

the enteric nervous system?

Answer 8

Local neuronal network co-ordinating the GI tract, with input from PNS and SNS

Question 9

Describe how the sympathetic and parasympathetic uses two neurone?

Answer 9

the first neurone makes connection ( a synapse) with the second, in a group of nerve cell bodies known as ganglion.
-preganglionic neuron fromCNS
-post ganglionic neuron innervates the target tissue (ONE NOTE)

Question 10

how is adrenaline released?

Answer 10

subset of pre ganglionic SNS fibres synapse with the adrenal medulla- releases adrenaline into circulation (ONE NOTE)

Question 11

what are the spinal cord division? (top to bottom)

Answer 11

medullary, cervical, thoracic, lumbar, sacral (one note)

Question 12

Describe somatic motor efferent neurone

Answer 12

single motor neurone innervating voluntary skeletal muscle

Question 13

what kind of muscle does the somatic nervous system innervate?

Answer 13

skeletal muscle for deliberate motion

Question 14

what kind of muscle does the autonomic nervous system innervate?

Answer 14

smooth and cardiac muscle for involuntary motion

Question 15

Describe neurones in the somatic nervous system

Answer 15

-heavily myelinated
-singular
-acetylcholine
-triggers a stimulatory response

Question 16

Describe neurones in the autonomic nervous system

Answer 16

-lightly or non-myelinated
-two neurone chain: preganglionic and postganglionic
-triggers a stimulatory or inhibitory response

Question 17

Describe the sympathetic nervous system anatomy

Answer 17

-fibres originate in the thoracic and lumbar region
-synapse in paired (two sets) paravertebral ganglia: bilateral connections to periphery (e.g blood vessels)
-synapse in unpaired (one set, midline) prevertebral ganglia
-synapse in adrenal medulla (preganglionic neurone straight to adrenal medulla)
-ganglia near spinal cord
ONE NOTE

Question 18

What does the sympathetic nervous system trigger?

Answer 18

-dilates pupil (more light)
-inhibits salivation
-relaxes bronchi
-accelerates heart beat
-inhibits peristalsis and secretion
-stimulates glucose production and release
-secretion of adrenaline and noradrenaline
-inhibits bladder contraction
-stimulates orgasm
-blood vessels constrict and relax to direct blood to working muscles (vascular shunt)

Question 19

Describe the length of neurones in the sympathetic nervous system

Answer 19

-short preganglionic neurones
-long postganglionic neurones

Question 20

Describe neurone lengths in the parasympathetic nervous system

Answer 20

-long preganglionic neurones
-short postganglionic neurones
parasympathetic ganglia are located in or close to target organs

Question 21

Describe the parasympathetic nervous system anatomy

Answer 21

-fibres originate in the medulla (brain) and sacral region
-parasympathetic ganglia are located in or close to target organs
-the vagus (10th cranial nerve, X) provides parasympathetic innervation of heart, lungs, pancreas and GI tract

Question 22

What responses does the parasympathetic system trigger?

Answer 22

-constricts pupils
-stimulates saliva flow
-constricts bronchi
-slows heartbeat
-stimulates peristalsis and secretion
-stimulates bile release
-contracts bladder

Question 23

what are the opposing actions between the PNS and SNS?

Answer 23

heart rate, airway tone, GI motility

Question 24

what are single system controls in the PNS and SNS?

Answer 24

liver (sympathetic), GI secretion (parasympathetic)

Question 25

what are coordinated effects between the PNS and SNS?

Answer 25

salivary secretion of fluid (parasympathetic) and enzymes (sympathetic)

Question 26

what neurotransmitters and hormone is involved in the ANS?

Answer 26

-neurotransmitter: acetylcholine and noradrenaline -hormone: adrenaline -these are all biogenic amine due to structure (one note)

Question 27

what are the two acetylcholine (ACh) receptors?

Answer 27

-nicotinic receptors, ligand gated ion channels, "fast for PNS and SNS" (2 subtypes) -muscarinic receptors, Gprotein coupled receptors- "flexible" (5 subtypes)

Question 28

what does noradrenaline and adrenaline bind to?

Answer 28

adrenoreceptors which are G protein coupled receptors. There are 5 subtypes (a1, a2, B1, B2, B3

Question 29

how does acetylcholine work in parasympathetic neurones?

Answer 29

-In postganglionic parasympathetic neurones- ACh activates muscarinic receptors on targets ONE NOTE -Acetylcholine is the main neurotransmitter in the parasympathetic nervous system

Question 30

Describe noradrenaline and adrenaline in the sympathetic nervous system

Answer 30

-NA and adrenaline are the main mediators -most postganglionic sympathetic neurones transmit noradrenaline, activating adrenoreceptors -tissue adrenoreceptors are activated by noradrenaline or circulating adrenaline -sympathetic innervation of sweat glands uses acetylcholine/ muscarinic receptors

Question 31

what main receptor is involved in the heart?

Answer 31

B1- AR

Question 32

what main receptor is involved blood vessels?

Answer 32

a1- AR B2- AR

Question 33

what main receptor is involved in the lungs?

Answer 33

B2- AR

Question 34

Describe salbutamol

Answer 34

selective for B2-adrenoreceptors in the lung over B1-adrenoreceptors in the heart

Question 35

what are the two divisions of the peripheral nervous system?

Answer 35

-sensory or afferent division (to CNS) -motor or efferent division (from CNS)

Question 36

Describe the somatic nervous system

Answer 36

-innervates skeletal muscle for deliberate motion -heavily myelinated and singular neurones -acetylcholine -stimulatory response

Question 37

Describe the autonomic nervous system

Answer 37

-innervates smooth and cardiac muscle for involuntary motion -lightly or non myelinated two neurone chain (preganglionic and postganglionic) -acetylcholine or norepineprine -stimulatory or inhibitory response

Question 38

Describe muscarinic receptors

Answer 38

-mainly found in the parasympathetic nervous system on the surfaces of smooth muscles, cardiac muscles and glands -G protein coupled receptor -function: regulate involuntary processes

Question 39

Describe nicotinic receptors

Answer 39

-found in the autonomic ganglia, the neuromuscular junction (where nerves meet muscles) and the central nervous system -ligand gated ion channel -function: stimulate muscle contractions and transmit signals between neurones

Question 40

what are the differences between adrenergic receptors and muscarinic receptors?

Answer 40

-adrenoreceptors respond to adrenaline and noradrenaline -muscarinic receptors respond to acetylcholine -adrenoreceptors found in sympathetic nervous system -muscarinic receptors found in parasympathetic nervous system -both G coupled protein receptors

Question 41

when is acetylcholine used in the sympathetic pathway?

Answer 41

in control of sweat glands and blood vessels