Autonomic

Question 1

the autonomic nervous system is made up of many _________

Answer 1

neural loops

it is all reflexive

Question 2

list the neurons that make up a neural loop within the autonomic nervous system.

Answer 2

1. interoreceptors
2. viscerosensory neurons
3. association neurons
4. autonomic motor neurons
5. effectors

Question 3

what are interoreceptors?

Answer 3

receptors in the ANS that monitor body internal conditions

Question 4

what are viscerosensory neurons?

Answer 4

ANS neurons that send/carry unconscious input to the CNS

Question 5

what is the role of association neurons in the ANS?

Answer 5

control center

function to formulate a response to viscerosensory input

located in a variey of integrating centers within the CNS

Question 6

list locations where association neurons in the ANS can be found

Answer 6

1. upper level emotional center (limbic)
2. hypothalamus
   
   • paraventricular nucleus
   • dorsomedial, posterior and mammillary nuclei
3. brain stem/reticular
   
   • CN 3, 7, 9, 10
   • ventrolateral medulla
4. spinal cord dorsal/lateral horns
   
   • T1-L2 and S1-S3

Question 7

autonomic motor neurons can be subdivded into what 2 categories?

Answer 7

sympathetic

parasympathetic

Question 8

list some categories for effector tissues in the ANS

Answer 8

1. smooth muscle (gut wall, blood vessels, etc.)
2. cardiac muscle
3. glands (secretory cells)

Question 9

how are sensory neurons different between the somatic and autonomic nervous system?

Answer 9

1. somatic → conscious, percieved sensation (special senses and somatic sense)
2. autonomic → primarily monitor conditions in the interior of the body
   
   • sensory receptors are chemoreceptors, mechanoreceptors
   • NOT consciously percieved

Question 10

how are motor neurons different between the somatic and autonomic nervous system?

Answer 10

1. somatic → always excite skeletal muscle to cause contraction
   
   • the effector they are stimulating has no intrinisc activity
2. autonomic → control effector function by either increasing or decreasing the intrinisc activity
   
   • the effector they are stimulating has intrinsic activity (like HR)

Question 11

how are motor (efferent) pathways different between the somatic and autonomic nervous system?

Answer 11

1. somatic → motor neuron pathway consists of 1 neuron going from ventral horn of spinal cord gray matter directly to effector muscle
2. autonomic → consists of 2 neurons
   
   • preganglionic
   • postganglionic

Question 12

what is a preganglionic neuron in a motor neuron pathway in the ANS?

Answer 12

neuron is located in the lateral horn of the spinal cord gray matter

or

in the cranical nerve nuclei of the brain stem.

they send myelinated axons to the 2nd (postganglionic) neuron

Question 13

what is a postganglionic neuron in the ANS?

Answer 13

located in a nerve cell ganglion which sends an unmyelinated axon to the effector (smooth/cardiac muscle or gland)

Question 14

T/F: most targets of ANS motor neurons have nerve endings from both the sympathetic and parasympatheic parts of the ANS?

Answer 14

TRUE

called dual innervation

one will increase activity while the other decreses it

the NT released by either determines if it will be increasing/decreasing activity

Question 15

differentiate between the location of sympathetic and parasympathetic preganglionic neurons

Answer 15

1. sympathetic → cell bodies located in lateral horn T1-L2
2. parasympathetic → cell bodies located in CN nuclei of brain stem (3,7,9,10) and lateral horn of S2-S4

Question 16

differentiate between the location of sympathetic and parasympathetic postganglionic neurons

Answer 16

1. sympathetic
   
   • sympathetic trunk (paravertebral) ganglia
   • prevertebral ganglia
   • adrenal gland cells of adrenal medulla
2. parasympathetic
   
   • ciliary ganglia
   • pterygopalatine ganglia
   • otic ganglia
   • submandibular ganglia

Question 17

what/where are the sympathetic trunk (paravertebral) ganglia?

Answer 17

two chains of ganglia that run the length of the vertebral column

located along the sides of the vertebral column

Question 18

what/where are the prevertebral ganglia?

Answer 18

lie anterior to the vertebral column and close to large abdominal arteries

include:

1. celiac
2. aorticorenal
3. superior mesenteric
4. inferior mesenteric ganglion

Question 19

where are parasympathetic ganglia located?

Answer 19

close to/within the organ of innervation

result is a long preganglionc fiber and a short postganglionic fiber

Question 20

what connects pre to postganglionic neurons?

Answer 20

1. white rami
2. gray rami
3. splanchnic nerves
4. vagus nerves
5. carotid periarterial plexus

Question 21

what do white rami connect?

Answer 21

these carry preganglionic sympathetic axons to paravertebral ganglia

Question 22

what do gray rami connect?

Answer 22

these carry postganglionic sympathetic axons back to spinal nerve for distribution with peripheral nerves

Question 23

what do splanchnic nerves connect?

Answer 23

carry preganglionic sympathetic axons from paravertebral chain to prevertebral ganglia

Question 24

describe how an autonomic motor pathway generally functions within the sympathetic system

Answer 24

mass activate targets due to divergence of neurons resulting in stimulation of many effector targerts, and release of the hormone epinephrine

Question 25

describe how an autonomic motor pathway in the parasympathetic system generally functions

Answer 25

do not mass activate target organs instead at the target organ the fiber synapses with a few postganglionic neurons which act on only one target organ at that location

Question 26

what are the broad categories of neuron type according to NT/receptor?

Answer 26

1. Cholinergic → release ACh 2. Adrenergic → release NE

Question 27

T/F: all sympathetic and parasympathetic preganglionic neurons are cholingeric?

Answer 27

TRUE

Question 28

what type of postganglionic fibers are cholinergic?

Answer 28

all parasympathetic postganglionic neurons sympathetic postganglionic neurons to sweat glands

Question 29

cholinergic neurons will interact with what type of receptors?

Answer 29

cholingeric receptos: 1. nicotinic → always lead to depolarization/stimulation of target 2. muscarinic → found in all effectors innervated by PNS postganglionic neurons, can lead to either depolarization/hyperpolarization of the target

Question 30

adrenergic neurons will interact with what types of receptors?

Answer 30

adrenergic (alpha and beta) * 1's → depolarize and excite * 2's → hyperpolarize and inhibt

Question 31

what terminates the effects of NTs?

Answer 31

1. enzymatic inactivation * acetylcholinesterase * COMT * MAO 2. removed from synapse by endocytosis 3. NT diffuses out of synapse

Question 32

what regulates the activity of both PNS and SNS nerves to achieve a balance of inhibition and stimulation?

Answer 32

hypothalamus

Question 33

list the structures that are not dual innervated and recieve only sympathetic innervation

Answer 33

1. sweat glands (ACh sympathetic) 2. erector pili muscles 3. most blood vessels 4. adrenal medulla

Question 34

why are sympathetic responses longer lasting than PNS responses?

Answer 34

1. divergence of postganglionic fibers to activate effector targets in several tissues at once 2. slower inactivation of NE in synapse 3. presence of NE and Epi from adrenal medulla in blood

Question 35

list body functions that are increased by parasympathetic nerves

Answer 35

SLUDD 1. salivation 2. lacrimation 3. urination 4. digestion 5. defecation

Question 36

list the body functions decreased by the parasympathetic nerves

Answer 36

1. HR 2. airway diameter 3. pupil diameter

Question 37

T/F: the cortex controls autonomic reflexes just like it does motor reflexes?

Answer 37

FALSE the hypothalamus controls autonomic reflexes there is a lack of awareness or consciousness with autonomic functions