Overview of the Nervous System and Spinal Nerves

Question 1

Comprised of the neuronal cell bodies, nerve fibers, and connective tissues of the brain and spinal cord

Answer 1

Central nervous system (CNS)

Question 2

Initiates, regulates, and coordinates body functions

Answer 2

CNS

Question 3

The CNS communicates with other functional components of the body via the

Answer 3

Peripheral nervous system (PNS)

Question 4

Collections of neuronal cell bodies within the CNS are called

Answer 4

Nuclei

Question 5

The nerve fibers of the CNS are commonly arranged into discreet bundles called

Answer 5

Tracts

Question 6

Comprised of the neuronal cell bodies, nerve fibers and connective tissues that lie outside the CNS

-conveys information between CNS and peripheral structures

Answer 6

Peripheral Nervous System (PNS)

Question 7

Collections of neuronal cell bodies outside of the CNS are referred to as

Answer 7

Ganglia

Question 8

Comprised of peripheral nervous tissue responsible for
carrying signals to and from skeletal muscles, tendons,
joints and skin

Answer 8

Somatic Nervous System

Question 9

Conveys sensations of pain, temperature, tough, and proprioception from the periphery to the CNS

Answer 9

Somatic PNS

Question 10

The cell bodies of lower somatic motor neurons are located in the

Answer 10

Ventral horn of spinal cord

Question 11

The cell bodies of somatic sensory neurons are located in

Answer 11

Dorsal root (spinal) and cranial nerve ganglia

Question 12

The internal organs in the main cavities of the body, especially those in the abdomen, e.g., the intestines.

Answer 12

Viscera

Question 13

Comprised of peripheral nervous tissue responsible for
carrying signals to and from the viscera.

-conveys visceral sensations such as distension

Answer 13

Autonomic PNS

Question 14

The Autonomic PNS is comprised of

Answer 14

1. ) Sympathetic nervous system

2. ) Parasympathetic nervous system

Question 15

Elicits the so-called “fight or flight” response, which includes pupilary dilation, increased heart rate, blood pressure, and sweating

Answer 15

Sympathetic nervous system

Question 16

Controls digestive functions, slows the heart rate, and constricts the pupils

Answer 16

Parasympathetic nervous system

Question 17

Both utilize two motor neurons in the peripheral path to innervate smooth and cardiac muscle

Answer 17

Sympathetic and parasympathetic nervous systems

Question 18

The anatomic unit of the nervous system

-consists of a cell body, dendrite(s), and an axon

Answer 18

Neuron

Question 19

Microscopically, neurons can be classified as being

-based on the number of processes associated with their cell body

Answer 19

Multipolar, bipolar, or unipolar

Question 20

Functionally, neurons are classified as being either

Answer 20

Motor (efferent) or Sensory (afferent)

Question 21

These neurons are multipolar and carry information away from the CNS

-cell bodies are located in the nuclei, within the ventral horn of spinal cord

Answer 21

Motor (efferent) neurons

Question 22

These neurons are unipolar and carry information towars the CNS

-cell bodies are clustered in ganglia located outside CNS

Answer 22

Sensory (afferent) Neurons

Question 23

Ganglia associated with spinal nerves are called

Answer 23

Dorsal root ganglia (spinal ganglia)

Question 24

Lies within the vertebral canal extending from the foramen magnum to the level of the intervertebral disc between L1/L2 vertebra

Answer 24

Spinal Cord

Question 25

Surrounded by three meningeal layers: dura mater (outermost), arachnoid mater (intermediate), and pia mater (innermost) and bathed in cerebrospinal fluid (CSF) that fills the subarachnoid space

Answer 25

Spinal cord

Question 26

The spinal cord consists of

Answer 26

White and grey matter

Question 27

Bundles of myelinated axons arranged in discreet fiber tracts

Answer 27

White matter

Question 28

Arranged into three major horns: ventral (motor), dorsal (sensory), and lateral (autonomic motor)

Answer 28

Grey matter

Question 29

Attach to the spinal cord via ventral (motor) and dorsal | (sensory) roots and functionally divide it into 31 spinal cord segments

Answer 29

Spinal nerves (31 pairs)

Question 30

There are 31 pairs of spinal nerves, which comprises

Answer 30

8 Cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal

Question 31

Spinal nerves exit the vertebral canal through intervertebral foramen. Where do the following exit? 1. ) Spinal nerves C1-C7 2. ) Spinal nerve C8 3. ) Thoracic, lumbar, and sacral nerves

Answer 31

1. ) Above the vertebrate (I.e. C3 exits above C3 between C2 andC3) 2. ) Below C7 3. ) Below their corresponding vertebra

Question 32

Spinal nerves exit the vertebral canal through

Answer 32

Intervertebral foramen

Question 33

Each spinal nerve is attached to the spinal cord via a

Answer 33

1.) Ventral (motor) root and a 2.) Dorsal (sensory) root

Question 34

The ventral root carries only motor nerve fibers and the dorsal root carries only sensory nerve fibers. these roots merge to form the

Answer 34

Mixed (motor and sensory) spinal nerve

Question 35

The spinal nerve divides into two, forming a -also mixed nerves

Answer 35

Ventral ramus and dorsal ramus

Question 36

What three things do dorsal rami innervate?

Answer 36

1. ) Skin of back 2. ) True back muscles 3. ) Zygapophyseal joints

Question 37

Innervate the remainder of the skin and skeletal muscles of the neck, trunk, and limbs

Answer 37

Ventral rami

Question 38

The skin of the neck, body wall and limbs is divided up | into segments or slices called

Answer 38

Dermatomes (skin slice)

Question 39

Each dermatome is innervated by the

Answer 39

Dorsal or ventral rami of spinal nerves

Question 40

Dermatome segments overlap eachother such that innervation of the ventral T10 dermatomal segment is supplied in part by

Answer 40

T9 and T11 ventral rami

Question 41

Thus, complete anesthesia of the T10 dermatomal segment would require knocking out the

Answer 41

T9,T10, and T11 ventral rami

Question 42

The portion of the PNS responsible for monitoring and regulating visceral functions

Answer 42

Autonomic Nervous System

Question 43

Primarily responsible for motor innervation of smooth muscle lining blood vessels, cardiac muscle and sweat glands and sensory innervation of viscera

Answer 43

Sympathetic ANS

Question 44

Primarily responsible for motor innervation of smooth muscle lining digestive tract, cardiac muscle and salivary glands and sensory innervation of viscera

Answer 44

Parasympathetic ANS

Question 45

Distributed with spinal nerves and blood vessels

Answer 45

Sympathetic nerve fibers

Question 46

Distributed with cranial nerves and pelvic autonomic nerves

Answer 46

Parasympathetic nerve fibers

Question 47

Both multipolar neurons, which carry signals away from the CNS

Answer 47

Somatic and visceral motor neurons

Question 48

Innervates skeletal muscle and takes a 1 motor neuron pathway from CNS

Answer 48

Somatic motor

Question 49

Innervate smooth muscle, modify cardiac muscle and glands, and takes a 2 motor neuron pathway from CNS

Answer 49

Visceral motor

Question 50

A single neuron pathway from CNS to skeletal muscle. Cell bodies are multipolar and located in the ventral (motor) horn of the spinal cord

Answer 50

Somatic Motor (efferent)

Question 51

For visceral motors, cell bodies of the first motor neuron (preganglionic) are located in the

Answer 51

CNS

Question 52

For visceral motors, cell bodies of the second motor neuron (post ganglionic) are located in the

Answer 52

Ganglia in PNS

Question 53

Preganglionic neurons innervate ONLY

Answer 53

Post ganglionic neurons (directly innervates visceral structures)

Question 54

Sympathetic and parasympathetic motor innervation of smooth muscle, cardiac muscle and glands both require a two neuron pathway with the first neuron located in the CNS and the second neuron in the

Answer 54

PNS

Question 55

Where are the preganglionic bodies of sympathetic motors located? -referred to as thoracolumbar outflow

Answer 55

Lateral horn of T1-L2

Question 56

Where are the postganglionic cell bodies of sympathetic motors located?

Answer 56

Paravertebral and prevertebral ganglia

Question 57

Where are the preganglionic bodies of parasympathetic motors located? -craniosacral outflow

Answer 57

Brainstem nuclei and lateral horn of spinal cord segments S2-S4

Question 58

Where are the postganglionic cell bodies of parasympathetic motors located?

Answer 58

4 discrete ganglia of the head and enteric ganglia of the gut

Question 59

Which has a more limited distribution, the parasympathetic or sympathetic system?

Answer 59

Parasympathetic

Question 60

Does not innervate smooth muscle or glands associated with somatic structures and is therefore not distributed to the trunk or limbs

Answer 60

Parasympathetic system

Question 61

Distributed throughout the entire body

Answer 61

Sympathetic neurons

Question 62

Before being distributed, all preganglionic sympathetic fibers enter paravertebral ganglia from T1-L2 via

Answer 62

White rami communicans

Question 63

The location of sympathetic preganglionic cell bodies found only from T1-L2 spinal cord segments

Answer 63

Lateral horn

Question 64

Carries preganglionic sympathetic motor axons to spinal nerve -also carries somatic motor axons

Answer 64

Ventral root

Question 65

All carry somatic motor axons, somatic sensory fibers, and postganglionic sympathetic axons

Answer 65

Spinal nerves

Question 66

Carry all of those fibers plus visceral sensory and | preganglionic sympathetic axons

Answer 66

Spinal nerves from T1-L2

Question 67

Carries pre- and postganglionic sympathetic axons -Carries somatic motor and sensory fibers and visceral sensory fibers

Answer 67

Ventral Ramus

Question 68

Connects ventral rami of spinal nerves T1-L2 with paravertebral ganglia, and carries preganglionic sympathetic axons

Answer 68

White ramus communicans

Question 69

Connects ventral rami of all spinal nerves with paravertebral ganglia, and carries postganglionic sympathetic axons that are distributed to somatic structures

Answer 69

Gray Ramus Communicans

Question 70

Sympathetic chain of ganglia located alongside the vertebral column -contain postganglionic cell bodies

Answer 70

Paravertebral ganglia

Question 71

Connects paravertebral and prevertebral ganglia and carries preganglionic sympathetic axons -also carries visceral sensory fibers

Answer 71

Splanchnic Nerve

Question 72

Contain postganglionic cell bodies whose axons are distributed to abdominopelvic viscera

Answer 72

Prevertebral ganglia

Question 73

Spinal nerves T1-L2 provide innervation primarily to the

Answer 73

Trunk

Question 74

The blood vessels and sweat glands associated with the trunk are innervated by -travel in the rami of T1-L2 spinal nerves

Answer 74

Postganglionic sympathetic nerve fibers

Question 75

Provide innervation to the upper limb

Answer 75

Spinal nerves C5-T1

Question 76

Provide innervation to the lower limb

Answer 76

L2-S4

Question 77

The blood vessels and sweat glands associated with the limbs are innervated by postganglionic sympathetic nerve fibers that travel in the

Answer 77

Rami of the spinal nerves

Question 78

The upper and lower limb spinal nerves (besides T1 and L2) do not have

Answer 78

Preganglionic cell bodies or white rami communicates

Question 79

The lack of white rami communicates means that there is no direct entry to the

Answer 79

Paravertebral ganglia

Question 80

Neurons that convey somatic sensations are anatomically identical to those neurons that convey visceral sensations. Both are unipolar neurons with cell bodies located in a

Answer 80

Ganglion

Question 81

Innervates skin, muscle, and joints and conveys pain, temperature, touch, and proprioception

Answer 81

Somatic sensory neurons

Question 82

What is the location of the cell bodies of somatic sensory neurons?

Answer 82

Dorsal root ganglia from C2-Co

Question 83

The somatic sensory neurons take the same pathway as the motor pathway up to the spinal nerve. Then it follows the

Answer 83

Dorsal root to the dorsal horn

Question 84

Innervates viscera, glands, and blood vessels and conveys distension, nausea, and hunger

Answer 84

Visceral sensory neurons

Question 85

What is the location of the cell bodies of visceral sensory neurons

Answer 85

Dorsal root ganglia from T1-L2

Question 86

Visceral sensory neurons follow the same pathway as the motor pathway up till the spinal nerve. Then they follow the dorsal root to the

Answer 86

Dorsal horn

Question 87

How many neurons do the following require? 1. ) Somatic and visceral motor pathway 2. ) Somatic and visceral sensory pathway

Answer 87

1. ) 2 | 2. ) 1

Question 88

Somatic sensory and visceral sensory are both part of the

Answer 88

Autonomic Sensory (afferent) innervation

Question 89

Convey some pain, but are mostly involved with visceral reflexes such as monitoring blood pressure

Answer 89

Parasympathetic afferent fibers

Question 90

Travel in cranial nerves and pelvic splanchnic nerves along with visceral efferent fibers

Answer 90

Parasympathetic afferent fibers

Question 91

Parasympathetic afferent cell bodies are located in the cranial nerve sensory ganglia and dorsal root ganglia of spinal nerves

Answer 91

S2-S4

Question 92

Go from a stimulus back to the spinal cord

Answer 92

Afferent Nerve

Question 93

Go from the spinal cord to a body part

Answer 93

Efferent Nerve

Question 94

Occurs because visceral afferent fibers synapse on the same neurons in the dorsal horn of spinal cord segments T1-L2 as the somatic afferent fibers

Answer 94

Referred pain