Lecture 6 - Autonomic Nervous System

Question 1

ANS is predominantly an _____ system

Answer 1

efferent

Question 2

the ANS transmits impulses from ____ to ____

Answer 2

transmits impulses from CNS to peripheral organ systems

Question 3

three subdivisions of the ANS

Answer 3

Sympathetic, Parasympathetic, Enteric

Question 4

Is ANS a two or one neuron transmission

Answer 4

ANS is always a 2 neuron system

Question 5

is somatic nervous system a 1 neuron system or 2 neuron system

Answer 5

1 neuron system

Question 6

describe the path of transmission of the ANS starting at the central nervous system to the effector organ

Answer 6

CNS –> preganglionic fiber –> preganglionic NT to the postganglionic fiber at the level of the autonomic ganglion –> postganglionic fiber –> postganglionic NT at varicosity –> effector organ

Question 7

*****compare and contrast somatic nervous system and autonomic nervous system (important, said would be on test)

Answer 7

Somatic: one neuron connects directly to effector, connects only to muscle (skeletal), only excitatory effects, one transmitter

Autonomic: two neurons connect to effector, can be a muscle or a gland (smooth or cardiac muscle), can be released directly to blood stream (ex. adrenal medulla), Both inhibitory and excitatory effects (ex. heart rate)

Question 8

is fight or flight a branch of sympathetic or parasympathetic

Answer 8

sympathetic

Question 9

what are some of the effects of the sympathetic nervous system

Answer 9

pupil dilation, vasoconstriction (GI, skin, brain, periphery), goosebumps, sweating, vasodilation (in heart, skeletal muscle, lungs), increased HR and BP, bronchodilation

Question 10

is “rest and digest” controlled by parasympathetic or sympathetic

Answer 10

Parasympathetic

Question 11

does the somatic NS have ganglia

Answer 11

naur

Question 12

2 kinds of ACh receptors

Answer 12

muscarinic and nicotinic

Question 13

Describe muscarinic receptor action and targets

Answer 13

action: can be inhibitory and excitatory depending on receptor subtype (ex. M1-5)

Target tissue (ex. bronchoconstriction, decreased heart rate)

Question 14

Describe nicotinic receptor action and targets

Answer 14

Action: excitatory, fast (ex. noticing a predator)

Target: post ganglionic (parasympathetic + sympathetic)

Question 15

Name the norepinephrine receptors and wether they are excitatory or inhibitory

Answer 15

R-alpha: excitatory (except for gut)

R-beta 1: Excitatory/ inhibitory

R beta 2: inhibitory

Question 16

where are ANS norepinephrine receptors located

Answer 16

all ANS norepinephrine receptors are located on target tissues (target effectors)

Question 17

Describe the key structure for controlling autonomic function

Answer 17

hypothalamus: key for thermoregulation, BP, heart rate, and multiple other functions

Question 18

is control of the ANS accomplished by one centres or multiple centres in the brain

Answer 18

complex, accomplished by multiple centers

Question 19

Describe the relationship between the enteric NS, parasympathetic and sympathetic nervous systems

Answer 19

enteric nervous system generally functions independently of sympathetic and parasympathetic nervous system but can be influenced by them

Question 20

Name some neurotransmitters contained in the enteric nervous system

Answer 20

serotonin (5-HT),

Question 21

Functions of the enteric system

Answer 21

Motility (peristalsis), Secretions (digestive enzymes), fluid regulation, GI blood flow

Question 22

name the layers of the enteric system starting at the lumen, working outwards

Answer 22

lumen
mucosal
submucosal
submucosal plexus
circular muscle
Mysenteric plexus
longitudinal muscle
serosa

Question 23

describe the serosa

Answer 23

double membrane lining closed cavities

Question 24

what is longitudinal muscle

Answer 24

smooth muscle

Question 25

Describe the myenteric plexus

Answer 25

neural controls motility and peristalsis Contains neurons responsible for regulating enzyme output of adjacent organs (extensive innervation)

Question 26

what is circular muscle

Answer 26

smooth muscle

Question 27

describe the submucosal plexus

Answer 27

neural control for ion and water transport contains sensory cells that communicate with the mesenteric plexus and motor fibers stimulate secretions of fluid into lumen

Question 28

describe the lumen

Answer 28

no nerves enter this area, where digestion occurs

Question 29

describe the mesentary

Answer 29

attaches bowel to body wall and contains major arteries, veins, lymphatics and external nerves

Question 30

Describe the parasympathetic nervous system control of the enteric nervous system

Answer 30

PNS is generally stimulatory - increases secretions, motility and blood flow (rest and digest)

Question 31

Describe the sympathetic nervous system control of the enteric nervous system

Answer 31

SNS is inhibitory to the ENS, reduces secretions and decreases blood flow and motility

Question 32

compare and contrast the locations of preganglionic neurons of sympathetic vs parasympathetic pathways

Answer 32

Sympathetic: - confined to thoracolumbar regions/ thoracolumbar in nature parasympathetic: - largely sacral and brainstem (craniosacral)

Question 33

Describe the axon length of sympathetic autonomic neurons vs parasympathetic autonomic neurons

Answer 33

sympathetic: preganglionic neurons are very short in the 2 neuron system (neuron to effector is longer) parasympathetic: 1st order neuron has long range axons with short neurons synapsing onto effector organs

Question 34

what are the 3 exceptions of the sympathetic autonomic pathways where the pre-ganglionic fibers are longer than usual

Answer 34

coeliac ganglion, superior mesenteric ganglion, inferior mesenteric ganglion

Question 35

describe what NTs are release from 1st order and 2nd order neurons in the parasympathetic nervous system, what receptors they act on, and the actions at target sites

Answer 35

1st order neurons --> Ach at nicotinic receptors on 2nd order neurons --> 2nd order neurons release Ach --> muscarinic receptors on effectors --> increase exocrine secretions, increase GI smooth muscle contractions, decrease heart rate, constricts pupil

Question 36

describe what NTs are release by pre and post ganglionic fibers of the sympathetic nervous system, what receptors they act on, and the action at target sites

Answer 36

Preganglionic fibers --> Ach onto nicotinic receptors of postganglionic fibers --> Norepinepherine onto alpha and beta receptors increases splenic contractions, increase force of cardiac muscle contractions, decrease contraction of GI smooth muscle, constricts peripheral blood vessels, dilates bronchial airways, dilates pupil

Question 37

describe sympathetic innervation of the adrenal medulla, what is released and the downstream effects

Answer 37

neuron --> Ach to nicotinic receptors on adrenal medulla --> adrenal medulla releases epinephrine and norepinepherine into the blood (note: these are now considered hormones) --> alpha and beta receptors --> fight or flight actions (increases splenic contractions, increase force of cardiac muscle contractions, decrease contraction of GI smooth muscle, constricts peripheral blood vessels, dilates bronchial airways, dilates pupil)

Question 38

Which norepinephrine receptor receives signals exclusively from blood (hormones)

Answer 38

Beta 2 receptors

Question 39

Radial muscle - iris NE receptor and response

Answer 39

Alpha 1 receptor, contraction (dilates pupils)

Question 40

Cilliary muscle cholinergic response

Answer 40

contraction for near vision (lens)

Question 41

Cilliary muscle NE receptor and response

Answer 41

Beta 2 receptor, relaxation for far vision

Question 42

Sinoatrial node Cholinergic impulse

Answer 42

decrease in heart rate

Question 43

sinoatrial node NE receptor and response

Answer 43

Beta 1 receptor, increase in heart rate

Question 44

Atria Cholinergic response

Answer 44

decrease contractility

Question 45

Atria NE receptor and response

Answer 45

beta 1, increase contractility and conduction velocity

Question 46

AV node cholinergic response

Answer 46

AV block

Question 47

AV node NE receptor and NE response

Answer 47

B1, increase in conduction velocity

Question 48

Ventricles NE receptor and response

Answer 48

B1, increase contractility and conduction velocity

Question 49

Coronary, skel. muscle, pulmonary, renal arterioles cholinergic impulse

Answer 49

dilation (sometimes skel. muscle)

Question 50

Coronary, skel. muscle, pulmonary, renal arterioles NE receptor and response

Answer 50

Alpha --> constriction Beta 2 --> dilation

Question 51

skin, mucosal, salivary gland NE receptors and response

Answer 51

alpha --> constriction

Question 52

Systemic veins NE receptor and response

Answer 52

alpha --> constriction beta 2 --> dilation

Question 53

bronchial muscle of lungs cholinergic impulse

Answer 53

contraction

Question 54

Bronchial muscle NE receptor and response

Answer 54

Beta 2 --> relaxation

Question 55

Bronchial gland of lung NE receptors and responses

Answer 55

alpha 1 --> decrease in secretion Beta 2 --> increase in secretion

Question 56

pilomotor muscles of skin NE receptor and response

Answer 56

alpha 1 --> contraction

Question 57

Salivary gland cholinergic response

Answer 57

profuse watery secretion

Question 58

salivary gland NE receptor and response

Answer 58

alpha --> scant, viscous secretion

Question 59

review slide 22, 15,14, 11,10,9

Answer 59

srsly >:(

Question 60

what are some of the effects of the parasympathetic nervous system

Answer 60

Vasodilation in periphery, urination and defecation, resting HR and BP, sexual arousal, salivation, contraction of pupil and lens, bronchoconstriction, digestion (enzymes and peristalsis)