Functional anatomy of ANS part I

Question 1

Two types of motor systems: Somatic (voluntary) and autonomic (non-voluntary)

Answer 1

…

Question 2

autonomic divided into…

Answer 2

parasympathetic/sympathetic systems

Question 3

nerve definition?

Answer 3

A bundle of axons (depending on the location, may be called a rootlet, root, trunk, division, cord, ramus, nerve or branch)

Question 4

nerve fiber definition?

Answer 4

Another term used to describe an axon

Question 5

ganglion definition?

Answer 5

An aggregation of functionally related nerve cell bodies OUTSIDE the central nervous system – can be sensory or motor

Question 6

nucleus definition?

Answer 6

An aggregation of functionally related nerve cell bodies INSIDE the central nervous system

Question 7

motor (efferent) neurons definition?

Answer 7

Nerve cells whose axons carry impulses (action potentials) out to muscles or glands (effector organs)

Question 8

sensory (afferent) neurons definition?

Answer 8

Nerve cells whose processes carry impulses (action potentials) to the central nervous system

Question 9

What does the somatic nervous system allow us to do?

Answer 9

Allows us to act on the external environment

The neurologic substrate that allows the individual to respond voluntarily to consciously perceived sensory signals

Question 10

What does the autonomic (self-governing) nervous system (ANS) allow us to do?

Answer 10

Allows us to act on the body’s internal environment

The neurologic substrate that acts to maintain homeostasis

We are not aware of the workings of the ANS

ANS sensory signals are not perceived consciously

Most ANS motor activities are not under voluntary control

Question 11

Both the somatic NS and the ANS have sensory neurons that carry singles into what???

Answer 11

integrative neurons!!

these are located within the brain and spinal cord and they construct an appropriate response

Question 12

motor neurons carry response back to effector cells

Answer 12

…

Question 13

Our entire behavioral repertoire can be reduced to combinations of these two actions:

1. The somatic NS causes voluntary muscles to contract
2. The ANS causes or modifies involuntary muscle contraction and glandular secretion

Answer 13

…

Question 14

1. The ANS has preganglionic neurons… these cell bodes reside where?
2. The preganglionic fibers (axons) then travel and synapse at post ganglionic neurons… where do these cell bodies reside?
3. the postganglionic fibers (axons) then travel to target organs

Answer 14

1. Cell bodies residen in the CNS! This is a nucleus

2. cell bodies reside outside the CNS in the periphery. This is a ganglion

Question 15

target organs for ANS are visceral effectors… this includes?

Answer 15

Visceral effectors (cardiac muscle, smooth muscle, glands) in head, thoracic cavity, abdominopelvic cavity, body wall and limbs

Question 16

what neurotransmitter is released at the ganglions/at the effector for parasympathetic?

Answer 16

acethylcholine for both locations!

Question 17

what neurotransmitter is released at the ganglions/at the effector for sympathetic?

Answer 17

ganglion - acetylcholine

effector - norepinephrine

Question 18

somatic nervous system only has one axon (no preganglionic axon, etc)… what neurotransmitter released?

Answer 18

acetycholine

Question 19

What are the four functional modalities that are found in a typical spinal nerve?

Answer 19

General Somatic Afferent (GSA)

General Somatic Efferent (GSE)

General Visceral Afferent (GVA)

General Visceral Efferent (GVE)

Question 20

General Visceral Efferent controls…

Answer 20

sweat glands, erector pilorum muscle, vasculature smooth muscle, gut tube

Question 21

The spinal cord is located in the upper 2/3 of the vertebral canal… how many spinal nerves?

Answer 21

31 pairs of spinal nerves

Question 22

The Conus medullar is = end of the spinal cord.. where is it located?

Answer 22

L2 adults

L3 neonate

Question 23

what enlargements are on the spinal cord?

Answer 23

cervical (c5-T1) - brachial plexus

lumbosacral (L1 to S3)

Question 24

what makes the butterfly shape on the spinal cord?

Answer 24

gray matter!

Question 25

make sure to look at all of the diagrams on these slides!!

Answer 25

...

Question 26

the dorsal root is sensory or motor?

Answer 26

SENSORY!!

Question 27

what is in the ventral horn?

Answer 27

cell bodies of motor neurons

Question 28

the spinal nerve is a mixed nerve... it has both sensory and motor components!

Answer 28

...

Question 29

sympathetic chain/trunk runs on either side of the vertebral column... also called the paravertebral ganglia

Answer 29

...

Question 30

the sympathetic chain runs from what level to what level?

Answer 30

base of the skull to the sacrum

Question 31

what connects the sympathetic chain to spinal nerves?

Answer 31

gray and white rami communicantes

Question 32

white vs gray rami... where are they placed?

Answer 32

white is more lateral, gray is more medial

Question 33

spinal ganglion off of the dorsal root.... | the gray and white rami are off of the spinal nerve (white off of the ventral rami)

Answer 33

...

Question 34

``` dorsal = sensory ventral = motor ```

Answer 34

...

Question 35

the thoracolumbar segment of the ANS is what? the craniosacral regions?

Answer 35

sympathetic parasympathetic

Question 36

ventral horn is bigger than the dorsal horn

Answer 36

...

Question 37

where are the lateral horns located? what is it also called? what is in the lateral horns?

Answer 37

only at the levels of T1 to L2 intermediolateral cell column (ML) preganglionic cell bodies - bilateral

Question 38

ventral horn is what... G??

Answer 38

GSE!!

Question 39

know slide with somatotopic arrangement of the intermediolateral cell column?

Answer 39

...

Question 40

GSE and GSA fibers enter and leave through the dorsal and ventral roots... no messing around for them

Answer 40

...

Question 41

GVA fibers behave ... but problems with GVE! can exit in a ton of funky ways

Answer 41

...

Question 42

Once the preganglionic sympathetic axon is in the sympathetic chain it may take four different anatomical routes to distribute the GVE sympathetic fibers to the body wall and limbs and the visceral structures!

Answer 42

....

Question 43

Preganglionic neurons of the sympathetic division originate where?

Answer 43

in the gray matter of the lateral horn of the spinal cord levels T1-L2 (thoracolumbar outflow)

Question 44

GVE fiber path...

Answer 44

goes from lateral horn ventral root white rami sympathetic chain ganglion from there can take many different paths!! usually goes through gray rami, then out though ventral rami