Nervous System

Question 1

Nervous system tree

Answer 1

CNS –>

PNS –> (Sensory, Motor (Somatic, Autonomic (Sympathetic, Parasympathetic) ) )

Question 2

How many pairs of spinal nerves are there? What does each spinal nerve contain?

Answer 2

31 pairs. Each spinal nerve contains both motor and sensory fibers

Question 3

What is the organization of spinal nerves? (Name and number)

Answer 3

8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal

Question 4

How many pairs of cranial nerves are there?

Answer 4

12 pairs

Question 5

Where do dorsal root ganglia cell bodies derive from?

Answer 5

Neural crest

Question 6

Where are the cell bodies for ventral root neurons and where did they derive from?

Answer 6

They are in the ventral region of spinal grey matter and they derived from neural tube

Question 7

How many paravertebral ganglia are there on each side of the spinal cord?

Answer 7

31 paravertebral ganglia

Question 8

How many white and grey rami communicans are there on each side of the spinal cord?`

Answer 8

14 white and 31 grey rami communicans

Question 9

If an axon travels via white rami communicans to a paravertebral ganglia but doesn’t synapse, then goes out to viscera, where will it synapse?

Answer 9

A prevertebral ganglia

Question 10

What are the five important sympathetic preganglionic splanchnic nerves we need to remember?

Answer 10

Greater, lesser, least, lumbar, and sacral

Question 11

In what prevertebral ganglia does each of the five sympathetic preganglionic splanchnics synapse?

Answer 11

Greater: celiac ganglion
Lesser: superior mesenteric ganglion
Least: aorticorenal ganglion
Lumbar: inferior mesenteric ganglion
Sacral: hypogastric plexus

Question 12

What are the origin fibers of the splanchnic nerves?

Answer 12

Greater: T5-T9
Lesser: T10-T11
Least: T12

Question 13

What is the acronym for the functions of the parasympathetic system?

Answer 13

SLUDD (salavation, lachrymation, urination, digestion, and defecation)

Question 14

Where do parasympathetic nerves leave the spinal cord and where do they synapse?

Answer 14

They leave via 1 of 4 cranial nerves or via sacral spinal cord segments S2-S4. They synapse in terminal ganglia near their end organs.

Question 15

The vagus nerve: what CN # is it and what does it innervate?

Answer 15

It is CN X, and it innervates many viscera including the heart, lungs, and the walls of the fore- and midgut of the GI tract

Question 16

Visceral afferent nerves that convey pain normally course with ________ nerves. Visceral afferents that convey physiologic sensations other than pain course with _______ nerves.

Answer 16

Visceral afferent nerves that convey pain normally course with sympathetic nerves. Visceral afferents that convey physiologic sensations other than pain course with parasympathetic nerves.

Question 17

Most sympathetic nerves enter the CNS between which two spinal nerves?

Answer 17

T1 and L2

Question 18

Since most visceral pain fibers course w/ sympathetic nerves to enter the CNS, most visceral pain is referred to which dermatomes?

Answer 18

T1 through L2

Question 19

Sympathetic postganglionic splanchnics: where do they originate and what do they innervate?

Answer 19

These are the cardiopulmonary splanchnics. Their presynaptic fibers arise in T1-T4, and they synapse in the upper thoracic and lower cervical ganglia, then immediately exit the sympathetic chain to innervated the larynx, trachea, bronchi, lungs, and heart

Question 20

Sympathetic preganglionic splanchnics: where do they originate and what do they innervate?

Answer 20

They originate between T5 and the lower lumbar nerves, and they innervate all many viscera in the abdomen and pelvis

Question 21

Parasympathetic preganglionic splanchnics: where do they originate and what do they innervate?

Answer 21

They leave the spinal column via S2-S4 nerves and travel straight to their destination, where they synapse in intrinsic ganglia. They innervate the descending and sigmoid colon, rectum, and pelvic viscera.

They should technically include the vagus nerve, which is CN X and innervates cardiopulmonary system, foregut, and midgut

Question 22

Parasympathetic postganglionic splanchnics: where do they originate and what do they innervate

Answer 22

NADDA: they don’t exist

Question 23

What innervates the deep back muscles, joints between vertebrae, and the skin of the medial 2/3 of the back?

Answer 23

dorsal ramus

Question 24

What is the name for a collection of cell bodies in the PNS?

Answer 24

ganglion

Question 25

What is the name for a collection of cell bodies in the CNS?

Answer 25

nucleus

Question 26

What is the name for a nerve containing autonomic fibers (usually but not necessarily preganglionic) and visceral sensory fibers that supply the viscera?

Answer 26

splanchnic nerve

Question 27

A bundle of axons inside the CNS

Answer 27

tract

Question 28

An intertwining of ventral rami of spinal nerves

Answer 28

plexus

Question 29

This contains axons of motor neurons only

Answer 29

ventral root

Question 30

cranio-sacral portion of the autonomic nervous system

Answer 30

parasympathetic

Question 31

This carries preganglionic sympatheti axons from the ventral ramus of a spinal nerve into the sympathetic paravertebral chain

Answer 31

white ramus communicans

Question 32

Axons from ganglia situated in or near the walls of viscera they innervate

Answer 32

postganglionic parasympathetic fibers

Question 33

Neurons whose cell bodies are in the lateral horn of the grey matter of the spinal cord. Their axons travel in the ventral roots, ventral rami, and white rami communicantes

Answer 33

preganglionic sympathetic fibers

Question 34

This division of the PNS innervates arrector pili muscles, vascular smooth muscle, and sweat glands of skin.

Answer 34

sympathetic nervous system