AUTONOMIC NERVOUS SYSTEM

Question 1

what does the ANS control?

Answer 1

controls the ability to maintain homeostasis in an ever changing environment

Question 2

why is the ANS seen as a unique functional entity?

Answer 2

it is part central and part peripheral

Question 3

how many neurons are connected to effector for SoNS+ANS?

Answer 3

SoNS-1

ANS-2

Question 4

what do SoNS+ANS connect to?

Answer 4

SoNS-skeletal muscle

ANS-smooth and cardiac muscle, glands, fat cells

Question 5

do SoNS+ANS have excitatory or inhibitory effects?

Answer 5

SoNS- exitatory

ANS- I+E

Question 6

what neurotransmitter do SoNS+ANS use?

Answer 6

SoNS- Ach

ANS-Ach and noradrenaline

Question 7

where are the cell bodies located in SoNS+ANS?

Answer 7

SoNS-within the CNS

ANS-outside the CNS

Question 8

are the axons non-myelinated or myelinated for SoNS+ANS?

Answer 8

SoNS-myelinated
ANS- pre-ganglionic myelinated
post-ganglionic non-myelinated

Question 9

what is the function of the ANS?

Answer 9

regulates functions of daily living and functions at the subconscious level
Involved in regulating internal organs and involuntary actions

Question 10

what are the 3 anatomical sub-divisions of the ANS?

Answer 10

Sympathetic
Parasympathetic
Enteric (or intrinsic)

Question 11

what is the enteric/intrinsic sub-division of the ANS?

Answer 11

comprises the intrinsic nerve plexus of the GI tract, closely interconnected with the symp/parasymp systems

Question 12

what are examples of ANS function?

Answer 12

Body temp. control
Gut motility+secretion
Heart rate+force
Blood pressure
Blood glucose & FA
Micturition
Defection
expressive aspects of emotion

Question 13

what is the fight to flight response?

Answer 13

Sympathetic system mobilises the body during extreme situations (fear, exercise, rage)

Question 14

what is the rest and digest division?

Answer 14

Parasympathetic division performs maintenance activities and conserves body energy. Most effective in non-stressful situations

Question 15

where do parasympathetic fibres emerge from?

Answer 15

from the brain and the spinal cord at the sacral level

Question 16

where do sympathetic fibres originate from?

Answer 16

from the thoracic and lumbar regions of the spinal cord from T1 to L2

Question 17

what length are the fibres for the sympathetic NS?

Answer 17

Short pre-ganglionic and long post-ganglionic fibres

Question 18

where do the ganglia lie in the sympathetic NS?

Answer 18

near the spinal cord and vertebral column

Question 19

do the axons branch in the sympathetic NS?

Answer 19

Axons branch profusely, allowing influence over many organs

Question 20

what length are the fibres for the parasympathetic NS?

Answer 20

Long pre-ganglionic and short post-ganglionic fibres

Question 21

where do the ganglia lie in the parasympathetic NS?

Answer 21

ganglia lie far away from the CNS, in or near the organs innervated

Question 22

do the axons branch in the parasympathetic NS?

Answer 22

Axonal branching is diffuse and localised

Question 23

what is the function of the fight or flight response?

Answer 23

Co-ordinating responses to emergencies or vigorous muscular activity, and discrete control of organs

Question 24

are many organs affected by the F or F response?

Answer 24

In stressful situations several or all organs affected, i.e. system discharges as a unit, amplified by adrenaline release from adrenal medulla

Question 25

what is the function of the R and D response?

Answer 25

Conservation and restoration of energy Discrete and localised function on individual organs or regions SLUDD

Question 26

what does SLUDD stand for?

Answer 26

salivation, lacrimation, urination, digestion, and defecatio

Question 27

give and example when the parasymp and symp innervations are physiologically antagonistic

Answer 27

activation of parasympathetic stimulation slows HR whereas activation of sympathetic nervous system increases HR

Question 28

give an example when the parasymp and symp innervations are similar

Answer 28

Saliva secretion

Question 29

what are the symp and parasymp response to saliva production?

Answer 29

P-causes large vol of watery, enzyme-rich secretion & increased BF to the salivary glands S-small volume of thick viscous secretion, reduces BF to the salivary glands

Question 30

give an example when the 2 systems oppose each other but aren't equally important

Answer 30

In the gut, parasymp dominates over symp, parasymp is main motor nerve to drive gut functions

Question 31

give examples of organs/tissues that are innervated by only one division

Answer 31

sweat glands, piloerector muscles, blood vessels receive only sympathetic innervation

Question 32

can opposing effects still happen when innervated by one division and why?

Answer 32

yes eg. blood vessels depend on location due to different receptor subtypes for transmitter

Question 33

explain the possible effects on blood vessels after sympathetic stimulation

Answer 33

dilates BV supplying skeletal muscles (β adrenoceptors) | constricts BV supplying skin & gut (α adrenoceptors)

Question 34

in the sympathetic division what neurotransmitter do most post-ganglionic receptors release?

Answer 34

noradrenaline, fibres are names adrenergic

Question 35

what other neurotransmitter can the sympathetic division release?

Answer 35

some innervation of sweat glands + BV uses ACh acting on muscarinic receptors (sympathetic cholinergic)

Question 36

in the parasympathetic division what neurotransmitter do post-ganglionic receptors release?

Answer 36

ACh, these fibres are named cholinergic

Question 37

what neurotransmitter so preganglionic axon terminals release?

Answer 37

always release ACh

Question 38

what are the 3 types that nicotinic Ach receptors fall into?

Answer 38

muscle (NMJ), ganglionic and CNS

Question 39

how many subunits do ligand-gated ion channels form?

Answer 39

5 subunits, the composition can vary

Question 40

what type of receptors do muscarinic receptors have?

Answer 40

typical G-protein coupled receptors

Question 41

how many subtypes are there for muscarinic receptors?

Answer 41

5 subtypes are known M1-M5