Intro into PNS 9/16

Question 1

White Matter

Answer 1

• composed of ascending and descending fiber tracts grouped in funiculi (fiber bundles), composed of smaller fasiculi
• funiculi (outer portion of the butterfly)
• posterior (sensory), lateral (mixed), anterior (mixed)

Question 2

White Matter

Answer 2

• composed of ascending and descending fiber tracts grouped in funiculi (fiber bundles), composed of smaller fasiculi
• funiculi (outer portion of the butterfly)
• posterior (sensory), lateral (mixed), anterior (mixed)

Question 3

Grey matter

Answer 3

“columns”

• seat of the neuron (cell bodies) within the spinal cord
• composed of dorsal, lateral, ventral horn

Question 4

Dorsal horn

Answer 4

= posterior horn
composed of neurons that give rise to fibers that complete simple reflex arcs, decussate (cross to the oppsotie side) or ascend to other sensory substations in the CNS

Question 5

ventral horn

Answer 5

= anterior horn

- contains neurons whose fibers innervate skeletal muscles

Question 6

lateral horn

Answer 6

(InterMedioLateral Cell Column) IMLCC

- contains autonomic pre-ganglionic neurons that innervate smooth muscles

Question 7

dorsal root

Answer 7

• for the most part, transmits afferent (sensory) fibers of somatic and visceral origins

Note: a “ganglion” (collection of cell bodies outside the CNS) exists on the dorsal root, which contains the cell bodies of ALL the afferent (sensory) fibers, except for vagal afferents, below the level of the head

Question 8

ventral root

Answer 8

For the most part transmits efferent “motor” fibers to somatic and visceral structures

Question 9

dorsal root ganglion

Answer 9

a dorsal root ganglion (or spinal ganglion) is a nodule on a dorsal root of the spine that contains cell bodies of nerve cells (neurons) that carry signals from sensory organs toward the appropriate integration center. Nerves that carry signals toward the central nervous system (brain or spinal cord) are known as afferent nerves.

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Question 10

spinal nerve

Answer 10

spinal cord –> rootlets –> single spinal nerve 00> bifoorcates into dorsal and ventral ramus

Question 11

dorsal primary ramus

Answer 11

• dorsal branch of the spinal nerve containing fiers of all types (mixed - sensory motor, somatic, visceral) which innervate cutaneous and subcutaneous areas of the dorsal surface of the head, neck and trunk, deep back muscles and joints of the spine

3 major things: skin of back, deep back muscles, joints of spine

Question 12

ventral rami

Answer 12

ventral branch of a spinal nerve containing fibers of ALL types which innervate the limbs and ventral torso

• they form ALL somatic nerve plexuses of the body, i.e. cervical, brachial, and lubosacral

Question 13

funiculi

Answer 13

spinal cord white matter

Question 14

31 pairs of spinal nerves

Answer 14

8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal
- the first spinal nerve exits between the skull and CV1; all others exit intervertebral foramina and, except for in the cervical region, are numbered in reference to the vertebra from which the exit BENEATH.

Question 15

Grey matter

Answer 15

“columns”

• seat of the neuron (cell bodies) within the spinal cord
• composed of dorsal, lateral, ventral horn

Question 16

Dorsal horn

Answer 16

= posterior horn
composed of neurons that give rise to fibers that complete simple reflex arcs, decussate (cross to the oppsotie side) or ascend to other sensory substations in the CNS

Question 17

ventral horn

Answer 17

= anterior horn

- contains neurons whose fibers innervate skeletal muscles

Question 18

lateral horn

Answer 18

(InterMedioLateral Cell Column) IMLCC

- contains autonomic pre-ganglionic neurons that innervate smooth muscles

Question 19

dorsal root

Answer 19

• for the most part, transmits afferent (sensory) fibers of somatic and visceral origins

Note: a “ganglion” (collection of cell bodies outside the CNS) exists on the dorsal root, which contains the cell bodies of ALL the afferent (sensory) fibers, except for vagal afferents, below the level of the head

Question 20

ventral root

Answer 20

For the most part transmits efferent “motor” fibers to somatic and visceral structures

Question 21

dorsal root ganglion

Answer 21

a dorsal root ganglion (or spinal ganglion) is a nodule on a dorsal root of the spine that contains cell bodies of nerve cells (neurons) that carry signals from sensory organs toward the appropriate integration center. Nerves that carry signals toward the central nervous system (brain or spinal cord) are known as afferent nerves.

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Question 22

spinal nerve

Answer 22

spinal cord –> rootlets –> single spinal nerve 00> bifoorcates into dorsal and ventral ramus

Question 23

dorsal primary ramus

Answer 23

• dorsal branch of the spinal nerve containing fiers of all types (mixed - sensory motor, somatic, visceral) which innervate cutaneous and subcutaneous areas of the dorsal surface of the head, neck and trunk, deep back muscles and joints of the spine

3 major things: skin of back, deep back muscles, joints of spine

Question 24

ventral rami

Answer 24

ventral branch of a spinal nerve containing fibers of ALL types which innervate the limbs and ventral torso

• they form ALL somatic nerve plexuses of the body, i.e. cervical, brachial, and lubosacral

Question 25

funiculi

Answer 25

spinal cord white matter

Question 26

31 pairs of spinal nerves

Answer 26

8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal
- the first spinal nerve exits between the skull and CV1; all others exit intervertebral foramina and, except for in the cervical region, are numbered in reference to the vertebra from which the exit BENEATH.

Question 27

Functional Fibrous components found within spinal nerves

Answer 27

GSA, GVA, GSE, GVE

Question 28

General Somatic Afferent

Answer 28

GSA = fibers which carry information from skeletal muscles, tendons and join capsules (proprioceptive) and from the outside of the body concerning pain, touch and temperature (exteroceptive)

• head is in dorsal root ganglion

Question 29

General Visceral Afferent

Answer 29

GVA = fibers, which carry information (distension, some pain) from internal structures (interoceptive)

• head is in dorsal root ganglion

Question 30

General Somatic Efferent

Answer 30

GSE = fibers which innervate skeletal muscle

• all motor neurons are in ventral horn

Question 31

General Visceral Efferent

Answer 31

GVE = autonomic fibers which innervate smooth muscle, cardiac muscle and glands

• motor neurons are located in ventral horn

Question 32

dermatome

Answer 32

the area of skin innervated by cutaneous branches of a single spinal nerve