Autonomic nervous system Flashcards Preview

MD2- Neuroscience Block > Autonomic nervous system > Flashcards

Flashcards in Autonomic nervous system Deck (13):
1

The ANS innervates almost all organs and tissue except for [.....]. It's purpose is to maintain [....].

skeletal muscle

homeostasis

2

the [.....] branch of the ANS has thoraco-lumbar spinal roots, while the [...] branch has cranio-sacral spinal roots.

note that no autonomic pathways originate from the [....or...]

sympathetic
parasympathetic

cervical spine or lumbar enlargement

3

Sympathetic PRE-ganglionic neurons are all located in the [....] spine region, between vertebrae [.....]. All these motor neurons lie clustered in the [....] cell column of the spinal cord grey matter, between the intermediate gray zone and lateral horn.

lumbo-sacral

T1 and L3

intermediolateral

4

sympathetic post ganglion neurons lie in two types of ganglia: [....] ganglia, the primary source of vasoconstrictor neurons (sympathetic chain);
and [....] ganglia, the source of neurons innervating non-vascular smooth muscle

paravertebral ganglia

prevertebral ganglia

5

where are the parasympathetic pre-ganglionic neurons located?

1. brainstem nuclei (edinger-westfal nucleus (CN III) in midbrain, salivatory nuclei (CN VII and IX) in upper medulla, and dorsal motor nucleus & nucleus ambiguus of vagus nerve (X) in middle medulla.

2. interomediolateral cell column of gray matter of spinal cord between S1 and S5

6

sacral post-ganglionic neurons of the PNS lie in the [...]. These are mixed ganglia as they also contain many [....] neurons. These sacral post ganglionic neurons have [....], making them very vulnerable to surgical injury

pelvic plexus

sympathetic

long axons

7

sympathetic (SNS) preganglionic neuron axons are [..short/long...], and release ACh on nicotinic postganglionic neurons that have [..short/long...] axons.
--->In general, sympathetic ganglia tend to be located [...proximity....] from their end organs.

Sympathetic postganglionic neurons release primarily [....] on end organs, but sometimes release ACh on organs with muscarinic receptors (ex. Sweat Glands).

Short
Long

FAR from their end organs.

noradrenaline (NA)/Norepinephrine

8

parasympathetic (PNS) preganglionic neuron axons are [..short/long...], and release ACh on nicotinic receptors of postganglionic neurons that have [..short/long...] axons.

--->In general, sympathetic ganglia are located [...proximity....] from their end organs.

PNS postganglionic neurons release [....] on muscarinic receptors of end organs.

Long
Short

Close proximity (or within).

ACh

9

In the somatic branch of the peripheral nervous system, there are no somatic motor ganglia as the neurons synapse and release [....] directly on [....] receptors of their end organs.

ACh

nicotinic

10

at their end organs, complex networks of un-myelinated axons release neurotransmitters at multiple sites along the axon, called [...] (appears as blebs along the axon on microscopy)

axon varicosities

11

central processing of AFFERENT autonomic information occurs in the [....], located in the [....].

These are [....] order sensory neurons, receiving input from visceral afferents coming from end organs.

**This is the key point for collecting the vast majority of sensory information.

nucleus of the solitary tract (NTS)
medullary portion of brainstem

second

**This is the key point for collecting the vast majority of sensory information.

12

At the NTS (nucleus tractus solitarius), info from visceral afferents either goes:

1) provides feedback to pre-ganglionic neurons in spinal cord and brain stem leading to a reflexes that control tissue/organ function

or

2)[.....]

2) provides information to higher centres (hypothalamus, parabrachial nucleus) to drive more complicated behaviours (coordinated behaviour, visceral, somatic, endocrine, emotion).

13

the [.....] is the most important brain region for coordination of central autonomic output.

hypothalamus