Autonomic Nervous System

Question 1

The CNS is comprised of:

Answer 1

pre-ganglionic ganglia

Question 2

The PNS is responsible for:

Answer 2

Synapse of post ganglionic cells

Question 3

The ANS functions without:

Answer 3

Conscious effort

Question 4

During SNS activation, the adrenal medulla promotes secretion of:

Answer 4

Adrenaline and noradrenaline

Question 5

During PSNS activation, the endocrine pancreas secretes:

Answer 5

Insulin and glucagon

Question 6

During SNS activation, the endocrine pancreas promotes secretion of:

Answer 6

Insulin

Question 7

Afferent neurons…

Answer 7

Are sensory, travel to the ventral horn

Question 8

Efferent neurons…

Answer 8

Are motor, travel down to the dorsal horn

Question 9

Define ganglia:

Answer 9

A bundle of nerves that sit within the ganglia and give-off post-ganglionic axons

Question 10

The SNS has its motor neurons within the:

Answer 10

Thoracic and Lumbar regions

Question 11

Within the SNS, ganglia are ____ to the spinal cord

Answer 11

Proximal

Question 12

Within the SNS, pre-ganglionic axons are shorter than post-ganglionic axons. T/F

Answer 12

True

Question 13

GI tract, urinary bladder and genitals activity decrease upon activation of the…

Answer 13

SNS

Question 14

The PSNS has its motor neurons within the ____

Answer 14

Brain stem and sacrum

Question 15

Within the PSNS, the ganglia are proximal to…

Answer 15

The organ innervated

Question 16

Autonomic Ganglia:

Answer 16

Bridges the central motor neurons to effector organs

Question 17

Post-ganglionic axons terminate at…

Answer 17

Varicosities embedded within smooth muscle

Question 18

Single-unit smooth muscle cells are innervated by ___

Answer 18

Gap junctions

Question 19

For contraction of multi-unit smooth muscle cells ____

Answer 19

Each cell must be individually innervated

i.e. within the eye

Question 20

Autoinhibition:

Answer 20

Neurotransmitters act back on presynaptic membrane to inhibit further release

Question 21

Activation of post-Synaptic adrenergic receptors (α1) by sympathetic nerve varicosities results in _____

Answer 21

Increased vasoconstriction.

Question 22

What is the minimum number of neurons that neural signals must propagate through from a visceral sensory receptor to a visceral effector organ?

Answer 22

3
From a visceral sensory receptor, neural signals will travel through a sensory neuron (1) to a pre-ganglionic neuron (2) in the ventral horn of the spinal cord. This pre-ganglionic neuron will then synapse with a post-ganglionic neuron (3) in an autonomic ganglion. Finally, the post-ganglionic neuron will innervate a visceral effector organ.

Question 23

Single-unit smooth muscle cells are able to contract simultaneously in a coordinated manner. Aside from the digestive system, where else in the body would single-unit smooth muscle cells exist?

Answer 23

Uterus and Bladder

Question 24

Direct acting cholinergic agonists bind to ____

Answer 24

Muscarinic or nicotinic receptors –> release acetylcholine

Question 25

Indirect acting reversible cholinergic agonists bind to ____

Answer 25

Acetylcholine

Question 26

Which neurotransmitters is responsible for the activation of sweat glands under sympathetic activation?

Answer 26

Acetylcholine

Question 27

Pre-ganglionic neurons release ____ to act on ____

Answer 27

Acetylcholine to act on nicotinic receptors

Question 28

PSNS post-ganglionic fibers release ___ to act on ___

Answer 28

Release ACh onto muscarinic receptors on the postsynaptic target organs

Question 29

SNS post-ganglionic fibres release ____ to act on ____

Answer 29

Adrenaline and noradrenaline to act on adrenergic receptors

Question 30

ATP also releases Na+ and acts faster in inducing contractions of the smooth muscle –> activating post-synaptic voltage-gatedCa2+ channels. T/F

Answer 30

True

Question 31

Within the neuroendocrine compartment, SNS pre-ganglionic fibres innervate _____

Answer 31

Chromaffin cells within adrenal medulla

Question 32

Chromaffin cells promote secretion of:

Answer 32

Na+ and anions

Question 33

Global broadcasting of the sympathetic nervous system activation is achieved by:

Answer 33

Chromaffin cells, as they reside near blood vessels –> where hormones are released for systemic circulation;

Question 34

Muscurinic receptors are agonized by:

Answer 34

Acetylcholine

Question 35

Nicotinic receptors are agonized by ____

Answer 35

Acetylcholine or nicotine

Question 36

Muscrurinic Receptor1: Located in gastric glands, _____

Answer 36

Gq coupled –> incr. Intracellular calcium –> incr. contraction, secretion, neurotransmission

Question 37

Muscrurinic Receptor2: Located on cardiac cells, ____

Answer 37

Gi coupled –> opening of K+ channels, hyperpolarisation and decr. HR

Question 38

Muscrurinic Receptor3: Located in smooth muscle i.e. Lungs, eyes, endocrine glands and the GI tract

Answer 38

Gq coupled –> incr. Intracellular calcium –> contraction, secretion, neurotransmission

Question 39

Muscrurinic Receptor 4, Muscrurinic Receptor 5: Not yet distinguished, however, are within the...

Answer 39

PSNS

Question 40

When nicotinic receptors are activated, they…

Answer 40

are permeable to Na+ and K+; rapid depolarization of the cell

Question 41

Nicotinic receptor1 are located at the….

Answer 41

Neuro-muscular junction

Question 42

Nicotinic receptor2 are located at the…

Answer 42

Post-ganglion neuron

Question 43

Adrenergic receptors are GPCRs and are agonized by…

Answer 43

Na+ and A-

Question 44

Which receptors are found in the parasympathetic NS?

Answer 44

Nicotinic and Muscarinic

Question 45

The Enteric NS is dependant on the…

Answer 45

CNS

Question 46

The myenteric plexus is located within the:

Answer 46

Muscularis externa

Question 47

The myenteric plexus controls ____ and consists of _______

Answer 47

Digestive tract motility Ascending neuronal network & Descending neuronal network

Question 48

The submucosal plexus is found within the:

Answer 48

Mucosa and submucosa

Question 49

The sub-mucosal plexus controls the:

Answer 49

Secretion, absorption, and local muscle movements

Question 50

For peristalsis –> bolus of food is travelling from Oral to Aboral

Answer 50

The stretching of intestinal wall stimulates neurons within the myenteric plexus. Simultaneously, the chemicals within the food stimulate sensory neurons within the submucosal plexus. Both sensory neurons branch into the ascending and descending networks. Ascending neuronal network release excitatory neurotransmitters (ACh acetylcholine and SP substrate P) to the circular muscle behind the bolus; causes contraction of circular muscle Descending neuronal network release inhibitory neurotransmitters (NO nitric oxide, VIP vasoactive intestinal peptide and ATP adenosine triphosphate) to longitudinal muscle to cause relaxation.

Question 51

Ascending neuronal network within the myenteric plexus release….

Answer 51

Excitatory neurotransmitter, acetylcholine

Question 52

Descending neuronal network within the myenteric plexus release….

Answer 52

Inhibitory neurotransmitters Nitric oxide, vasoactive intestinal peptide, and ATP

Question 53

Gastric Mixing:

Answer 53

Physical and chemical breakdown

Question 54

Segmentation:

Answer 54

Contractions move food in both directions

Question 55

Peristalsis:

Answer 55

One-way motion towards the anus

Question 56

Migrating Motor Complex:

Answer 56

Electrochemical activity within GI smooth muscle between meals

Question 57

From the CNS, the vagus innervation initiates the Pre-ganglionic PSNS fibers to…

Answer 57

1. Pre-synaptic synapse at ganglia 2. Release acetylcholine 3. Post-ganglionic fiber carries ACh from nicotinic receptor to muscarinic receptor 4. Released onto heart and vessels

Question 58

The Post-sympathetic adrenergic fibers initiate:

Answer 58

1. Pre-synaptic fibers synapse at the ganglia 2. Release ACh 3. Post-ganglionic fiber carries ACh from nicotinic receptor 4. Release norepinepherine onto α- adrenoceptor and β-andrenoceptors to the heart and vessels

Question 59

The Post-sympathetic dopaminergic fibres initiate:

Answer 59

1. Pre-synaptic fibres synapse at the ganglia 2. Release ACh 3. Post-ganglionic fiber carries ACh from nicotinic receptor 4. Post-sympathetic dopaminergic fibers release dopamine onto dopaminergic receptor at renal vessels

Question 60

The adrenal fibres initiate:

Answer 60

1. Pre-synaptic fibres synapse at adrenal ganglia 2. Release ACh to nicotinic receptor 3. Epinephrine an norepinepherine act on the α-adrenoceptor and the β-adrenoceptor at the heart and vessels

Question 61

Activation of post-synaptic adrenergic receptors (alpha 1 receptors) by sympathetic nerve variscoties results in…

Answer 61

Increased vasoconstricion

Question 62

The enteric system is:

Answer 62

- Part of the autonomic NS - Involved in the coordination of peristalsis - Composed of neurons in the muscle and submucosa of the guy - ACh is a key neurotransmitter

Question 63

The enteric system is influenced by the SNS or PSNS. T/F

Answer 63

True

Question 64

Voluntary defecation is due to…

Answer 64

- Stimulation of stretch receptors in the rectum - PSNS stimulation of smooth muscle at internal anal spincter - Voluntary stimulation of external spincter via motor neurons - An increase in abdominal pressure

Question 65

Within the SNS reganglionic neurons may have their cell bodies in spinal cord segments S2 through S4. T/F

Answer 65

False

Question 66

Within the SNS, ganglia are located relatively close to the central nervous system. T/F

Answer 66

True