A&p 15

Front 1

Describe the pathway of pre-ganglionic ANS motor neurons

Back 1

Autonomic motor neurons:

Pre-ganglionic contain a cell body in the CNS with its axon extending to the autonomic ganglion (neuronal cell bodies in the PNS).

All pre-ganglionic axon terminals release excitatory acetylcholine (ACh).

- Some synapse with post-ganglionic neurons in the ganglion and

- some with adrenal medulla chromaffin cells (instead of autonomic ganglion).

Front 2

Describe the pathway of post-ganglionic ANS motor neurons

Back 2

The cell body is within the autonomic ganglion, from which an unmyelinated axon goes towards the effectors (under unconscious control):

-smooth muscle

-cardiac muscle

-gland

Most sympathetic neurons secrete noradrenaline.

Sympathetic cholinergic neurons release ACh.

Chromaffin cells in adrenal medulla secrete noradrenaline and adrenaline.

All parasympathetic neurons secrete ACh.

These are either excitatory or inhibitory, depending on neuroendocrine state (i.e. fight or flight? Rest or digest?)

Front 3

Why is the sympathetic division called the thoraco-lumbar division?

Back 3

The preganglionic neurons have their cell bodies in the lateral horns of the gray matter in the spinal cord T1-L2 (and sometimes L3)

Front 4

Why is the parasympathetic division of the ANS pathway called cranio-sacral?

Back 4

The pre-ganglionic motor neuron cell bodies are found in the brain stem or in the gray matter of spinal cord segments S2-S4

Front 5

Where do the axons of the pre-ganglionic nerve cells (in the thoraco-lumbar divison of the ANS motor pathways) exit?

Back 5

Via the anterior root from the spinal cors

Front 6

How are the pre-ganglionic axons of the parasympathetic cranio-sacral division of the ANS motor pathways conveyed?

Back 6

1. Brain stem pre-ganglionic axons conveyed via CN III oculomotor, VII facial, IX glossopharyngeal, X vagus

2. S2-S4 pre-ganglionic axons conveyed via anterior roots of pelvic splanchnic nerves

Front 7

Where do the pre-ganglionic axons of the thoraco-lumbar autonomic neurons go to in the motor pathway?

Back 7

Sympathetic paravertebral ganglion change (aka sympathetic trunk) via white ramus communicans

Front 8

What are the types of parasympathetic ganglia that axons of the cranio-sacral pre-ganglionic axons extend to?

Back 8

1. Intramural ganglia - in wall of innervated organ

2. Terminal ganglia - located near innervated organ (see pic)

Front 9

What are the effectors of the vagus outflow (X) (parasympathetic division)?

Back 9

Heart, lungs, stomach, small intestine, part of large intestine, liver, gallbladder, pancreas

Front 10

What are the effectors of the S2-S4 outflow (the parasympathetic pelvic splnachnic nerves)?

Back 10

Part of large intestine, reproductive organs, ureters, urinary bladder

Front 11

What are four possible ways that axons can leave the sympathetic trunk?

Back 11

Form the:

1. Spinal nerves

2. Splanchnic nerves to adrenal medulla

3. Sympathetic nerves

4. Splanchnic nerves to abdominalpelvic organs

Front 12

Describe the sympathetic pathway for the pre-ganglionic axon involving the spinal nerve?

Back 12

After synapsing with post-ganglionic neurons in the sympathetic trunk ganglion, they leave via gray ramus communicans to the spinal nerve.

Effectors: skin of the neck, trunk, and limbs via the posterior and anterior rami

Front 13

Describe the sympathetic pathway of the pre-ganglionic axons involving the sympathetic nerve.

Back 13

After the pre and post ganglionic synapsis in the sympathetic trunk ganglion, axons leave and form the sympathetic nerves.

Some nerves enter ANS plexuses.

Post-ganglionic fibers extend to the thoracic cavity.

Front 14

Describe the sympathetic pre-ganglionic pathway involving the cephalic periarterial nerve fibers.

Back 14

After synapsis with post-ganglionic neurons in the superior cervical ganglion (in the sympathetic trunk ganglia), cephalic periarterial nerve fibers innervate innervate visceral effectors of the head

Front 15

Describe the sympathetic pre-ganglionic pathway involving the splanchnic nerve that go to the abdominopelvic organs

Back 15

The pre-ganglionic axon passes through the sympathetic chain ganglion and forms the splanchnic nerve which synapse with post-ganglionic neurons in the prevertebral ganglia (aka collateral ganglion) and innervate the abdominopelvic viscera

Front 16

Name the five collateral ganglion of the sympathetic thoraco-lumbar pathway.

Back 16

1. Celiac

2. Superior mesenteric

3. Inferior mesenteric

4. Aorticorenal

5. Renal

Front 17

Post-ganglion neurons from the celiac ganglion innervate

Back 17

Stomach, liver, gallbladder, pancreas, spleen

Front 18

Post-ganglion neurons from the superior mesenteric ganglion innervate

Back 18

Small intestine and proximal large intestine

Front 19

Post-ganglion neurons from the inferior mesenteric ganglion innervate

Back 19

Urinary bladder, sex organs, distal large intestine

Front 20

Post-ganglion neurons from the aorticorenal ganglion innervate

Back 20

Renal arteries and kidneys

Front 21

Post-ganglion neurons from the renal ganglion innervate

Back 21

Cortex of kidneys and ureters

Front 22

Effects on (abdominopelvic viscera) of the post-ganglionic fibers from the prevertebral ganglion include

Back 22

Vasoconstriction

Decreased digestive activity

Urogenital functions

Front 23

What happens to pre-ganglionic axons that pass through the sympathetic chain ganglion and collateral ganglion without synapsing?

Back 23

They synapse with the adrenal medulla cells via the splanchnic nerve

Front 24

Where and what type of cholinergic neurons release acetylcholine in the ANS? What hydrolyzes ACh?

Back 24

Released by

1. Both sympathetic pre-ganglionic neurons and some post-ganglionic neurons

2. All parasympathetic pre-ganglionic neurons and all parasympathetic post-ganglionic neurons

Hydrolyzed

-All at the NMJ

-acetylcholinesterase (AChE)

Front 25

What releases noradrenaline in the ANS (adrenergic)?

Back 25

Released by

1. Most sympathetic post-ganglionic neurons

2. Adrenal medulla (as hormones)

Front 26

How is noradrenaline action terminated?

Back 26

It is terminated by neuronal re-uptake by:

1. re-release

2. Intracellular hydrolysis by monoamine oxidase (MAO) or by catechol-O-methyl-transferase (COMT)

Also ended by glial uptake

Front 27

Where are nicotine cholinergic receptors located? What is the effect of ACh binding?

Back 27

Nervous system: Located in motor endplates at the NMJ of sympathetic and parasympathetic post-ganglionic neurons

Endocrine system: all chromaffin cells

Always excitatory

Front 28

Where are muscarinic cholinergic receptors located? What is the nature of ACh binding?

Back 28

Located on:

1. All parasympathetic effectors

2. Few sympathetic effectors (sweat glands)

Binding:

Excitatory when sodium channels open

Inhibitory when chlorine or potassium channels open

Front 29

Where are α-adrenergic receptors located? What is the nature of noradrenaline and adrenaline binding?

Back 29

Located in some sympathetic effectors.

Two subtypes of receptors:

α1-adrenergic receptors are excitatory, ex. located in dermal and GI blood vessels for vasoconstriction

α2-adrenergic receptors are inhibitory, ex. located in GI smooth muscle causing vasodilation, leading to decrease of muscle tone and peristalsis

Front 30

What are the receptor subtypes of β-adrenergic receptors and examples of where are they located?

Back 30

β1-adrenergic receptor is excitatory, ex. in heart and skeletal muscle

β2-adrenergic receptor is inhibitory, ex. in bronchiolar smooth muscle

β3-adrenergic receptor is only in brown fat (aka brown adipose tissue), and plays a role in thermogenesis using mitichondrial metabolism uncoupled from ATP synthesis

Front 31

Where are β-adrenergic receptors generally located?

Back 31

Some sympathetic effectors

Front 32

What are the relative potencies of noradrenaline and adrenaline to alpha and beta adrenergic receptors?

Back 32

Noradrenaline is more potent to alpha adrenergic receptors than beta adrenergic receptors.

Adrenaline is equally potent to alpha and beta receptors.

Front 33

What do visceral autonomic reflexes consist of?

Back 33

1. Interoceptors=dendritic end of sensory neuron or receptor cell/tissue

2. Sensory neuron

3. CNS interneuron(s) = integrating center

4. 2 motor neurons: pre- and post-ganglionic

5. Visceral effector

Front 34

What are five parasympathetic visceral reflexes?

Back 34

Swallowing, coughing

Light reflexes: illuminate one eye causes miosis (pupillary contraction) in both eyes

Urination

Defecation

Digestive motor reflexes

Decreased heart rate

Front 35

What are three sympathetic visceral reflexes?

Back 35

Cardio accelerator reflexes

Vasomotor reflexes (blood pressure increases, change in direction of blood flow)

Pupillary dilation reflex (dim late induces mydriasis)

Front 36

From what does the hypothalamus receive input?

Back 36

Cerebral cortex, limbic system

Front 37

What does output from the parts of hypothalamus influence in the ANS? Together, what do these parts achieve?

Back 37

Anterior and medial hypothalamic nuclei influence parasympathetic function.

Posterior and lateral hypothalamic nuclei influence sympathetic function.

Together: autonomic tone (balance between sympathetic and parasymp) via reciprical control (if one inc. the other dec.)

Front 38

What is "dual innervation"?

Back 38

Most organs receive both sympathetic and parasympathetic input.

Front 39

What organs receive only sympathetic innervation?

Back 39

Sweat glands, arrector pili muscle, kidney, spleen, blood vessels and adrenal medullae

Front 40

Name the various parasympathetic and sympathetic nerve "plexuses" (tangled networks of axons) in body cavities

Back 40

Cardiac plexus - supplies the heart

Pulmonary plexus - supplies the bronchial tree

Esophageal plexus -supplies the esophagus

Celiac plexus - stomach, pancreas, liver, gallbladder, kidneys, adrenal medulla, sex organs

Superior mesenteric plexus - small and large intestines

Inferior mesenteric plexus - large intestine

Hypogastric plexus - supply pelvic viscera

Renal plexus - renal arteries within kidneys and ureters

Front 41

Why is the sympathetic decision more widespread and longer lasting than the parasympathetic division?

Back 41

Because of the degree of divergence :

For every single pre-ganglion, there are 20 or more post ganglion neurons in the sympathetic system.

In the parasympathetic system, there are only 5 for one.

Front 42

What is the difference between the preganglionic fibers and postganglionic fibers of the sympathetic vs parasympathetic?

Back 42

Symp: preganglionic fibers short and postganglionic fibers long

Parasymp: preganglionic fibers long and postganglionic fibers short

Front 43

ANX reflex arcs involve:

1. autonomic ____ sensory neurons associated with____

2. CNS ___ ____

3. 2 ___ ___ neurons

a. ____ neuron

b. ____neuron (stimulating ))))(

Back 43

1. unipolar; interoceptors

Front 44

Somatic motor pathways include

- single motor neuorn in ____ (___)

1. ___ ___in CNS (spinal cord or brain stem)

2. axon that goes to the ___ ___,

3. ____ (ACh released at NMJ)

4. conscious control

Back 44

PNS (LMN)

1. cell body;

skeletal muscle;

excitatory

Front 45

Post-ganglionic ANS motor neuron

Neurotransmitters released by most sympathetic are _____.

Sympathetic cholinergic release ____

Back 45

noradrenaline;

ACh

Front 46

Post-ganglionic ANS motor neuron

Chromaffin cells release ___ and ___

All parasympathetic release ___

Back 46

noradrenaline; adrenalin;

ACh

Front 47

The two types of sympathetic ganglia include the ___ ___(or ___) ganglia

collateral (or _______) ganglia

Back 47

sympathetic trunk (paravertebral)

collateral (pre-vertebral)

Front 48

The pre-ganglionic axons that synapse with post-ganglionic neurons in the sympathetic paravertebral ganglion chain either leave via the ___ or ___nerve.

Back 48

spinal; sympathetic

Front 49

The pre-sympathetic axons that pass through the sympathetic chain ganglion can either synapse with the ____ _____ (i.e. celiac ganglion, superior mesenteric...) or pass through the ____ ___ and synapse with ___ ____ via the ___ nerve.

Back 49

collateral; collateral; adrenal medulla; splanchnic

Front 50

Parasympathetic terminal ganglia include:

- ____ganglion of CN ___

- ____ganglion of CN ___

-____ganglion of CN ___

-___ganglion of CN ___

Back 50

- ciliary; III

- pterygopalatine; VII

- submandibular; VII

- otic; VII

Front 51

Hypothalamic outputs for parasympathetic functions include the ___ and ___ hypothalamic ___.

For sympathetic functions, outputs include ___ and ___ hypothalamic ___

Back 51

anterior; medial; nuclei

posterior; lateral; nuclei