Spinal Nerves and Back Musculature

Question 1

Describe GSA Fibers

Answer 1

GSA FIber: Somatic Afferent Fibers. This means that the muscles, bones, and ligaments will send signals to the CNS when met with pain, temperature, or touch (sensory)

Question 2

Describe GVA fibers

Answer 2

GVA: Viseral Afferent Fibers. This means that the organs of the body will send signals to the ANS when met with pain, temperature, or touch (Sensory)

Question 3

Describe GSE Fibers

Answer 3

GSE: Somatic Efferent Fibers. This means the CNS sends motor signals to skeletal muscles (motor)

Question 4

Describe GVE Fibers

Answer 4

GVE: Viseral Efferent Fibers. This means the ANS sends motor signals to cardiac, smooth muscle, and gland secretion in order to function (motor)

Question 5

How many nerves are there in each section of the spine, and where do they exit?
- Cervical
- thoracic
-lumbar
- sacral
-coccyx

Answer 5

-Cervical (8): They exit superior to the vertebrae
-Thoracic (12): they exit inferior to their designated vertebrae
-lumbar (5): they exit inferior to their designated vertebrae
- sacral (5): the dorsal nerves exit posteriorly and ventral nerves exit anteriorly through the anterior/posterior foramina
-coccyx (1): inbetween sacrum and coccyx

Question 6

the length of the spinal cord is (longer or shorter) than the spinal column

Answer 6

shorter

Question 7

explain the increasing inferior angle of nerve exits

Answer 7

due to spinal cord growing faster and earlier than the spine

Question 8

ventral roots are sensory, motor, or mixed?

Answer 8

motor

Question 9

dorsal roots are sensory, motor, or mixed?

Answer 9

sensory

Question 10

ventral rami are sensory, motor, or mixed?

Answer 10

mixed

Question 11

dorsal rami are sensory, motor, or mixed?

Answer 11

mixed

Question 12

swelling on a nerve root is called

Answer 12

ganglion

Question 13

dorsal ramus supplies

Answer 13

• true back muscles (attaches directly to spine to perform spine action, not upper limb)
• middle 1/3 of skin

Question 14

ventral ramus supplies

Answer 14

-not true back muscles (superfical back group)
- lateral 2/3 of back skin

Question 15

describe cutaneous nerves

Answer 15

branches of dorsal and ventral rami of spinal nerves. controlled by mainly GSAs but are also supplied by some GVE fibers for sweat glands and blood vessels of the skin

Question 16

what dermatome is most associated with the belly button

Answer 16

T10

Question 17

what dermatome is most associated with the nipple

Answer 17

T4

Question 18

What is the common grouping of the superficial group of the back

Answer 18

• all are supplied by the ventral rami (except trapezius)
• all work to provide movement to the upper extremity

Question 19

muscles of the superfical back

Answer 19

-levator scapulae
- trapezius
- latissimus dorsi
- rhomboid major
-rhomboid minor

Question 20

what is the common action and innervation of serratus posterior superior/inferior

Answer 20

• both accessory respiration muscles
• both innverated by ventral rami

Question 21

what is the common action and innervation of splenius complex

Answer 21

-both will extend the neck/head
-when working seperately they laterally flex/rotate the neck (ipslateral)
-innervated by dorsal rami

Question 22

what is the common action and innervation of erector spinae group

Answer 22

-all innervated by dorsal rami
-all maintain erect posture, extend spine/head/neck

Question 23

what is the common orgin and insertion of erector spinae group

Answer 23

-all have orgin at the sacrum, iliac crest, and spinous process of lumbar and last 2 thoracic vertebrae
- inserts into ribs, transverse process, and skull

Question 24

what are the muscles of the erector spinae group (from lateral to medial)

Answer 24

• iliocostalis
• longissimus
  -spinalis

Question 25

what is the common action of all iliocostalis muscle segments

Answer 25

extension, lateral flexion of vertebral column (bottom 2 also assist with rib inspiration)

Question 26

what is the common action of all longissimus segments

Answer 26

extension, lateral flexion of vetebral column

Question 27

what is the common action and innervation of the deep transversospinalis group

Answer 27

-they pull spinous process towards transverse processes - stabilize spine when acting together - they slightly rotate the body to opp side -all are innervated by dorsal rami

Question 28

what are the muscles of the transversospinales group

Answer 28

-semispinalis - multifidus - rotatores

Question 29

describe the greater occipital nerve. what is its other name, what does it run with, what type of nerve is it

Answer 29

cutaneous sensory branch with no somatic motor. it runs with the occipital artery. dorsal ramus of C2

Question 30

whats is the subocciptal nerve a branch of

Answer 30

the dorsal ramus of C1

Question 31

what are the four suboccipital muscles

Answer 31

- rectus capitis posterior minor - rectus capitis posterior major -superior oblique capitis -inferior oblique capitis

Question 32

Describe the atlantoaxial joint (types of joint invloved, what type of joint is it, primary movement)

Answer 32

- atlas and axis (gliding joint) -atlas and dens (pivot joint) - synovial joint - primary used in rotation

Question 33

describe the alantooccipital joint. (types of joint invloved, what type of joint is it, primary movement)

Answer 33

-uses hinge joint - is a synovial joint - primary used in flexion and extension

Question 34

alar ligaments prevents

Answer 34

excessive rotation

Question 35

Action Grouping: Extension of the neck – Bilateral action of:

Answer 35

1. Iliocostalis cervicis 2. Longissimus capitis and cervicis 3. Semispinalis capitis and cervicis 4. Spinalis capitis and cervicis 5. Splenius capitis and cervicis 6. Trapezius

Question 36

Action Grouping: Lateral flexion/bending of the neck – Unilateral action of

Answer 36

1. Iliocostalis cervicis 2. Levator scapulae 3. Longissimus capitis and cervicis 4. Splenius capitis and cervicis

Question 37

Action Grouping: Rotation of the neck – Unilateral action of:

Answer 37

1. Levator scapulae (ipsilateral) 2. Longissimus capitis (ipsilateral) 3. Multifidus (contralateral) 4. Rotatores (contralateral) 5. Semispinalis capitis (contralateral) and cervicis (contralateral) 6. Splenius capitis and cervicis (ipsilateral)

Question 38

Action Grouping: Extension of the trunk vertebrae – Bilateral action of:

Answer 38

1. Erector spinae (longissimus thoracis and spinalis thoracis) 2. Multifidus 3. Rotatores 4. Semispinalis thoracis

Question 39

Action Grouping: Lateral flexion/bending of the trunk – Unilateral action of

Answer 39

Iliocostalis thoracis and lumborum 2. Longissimus thoracis 3. Multifidus 4. External and internal oblique (to be covered later) 5. Quadratus lumborum (to be covered later) 6. Spinalis thoracis

Question 40

Action Grouping: Rotation of the trunk – Unilateral action of:

Answer 40

1. Rotatores (contralateral) 2. Multifidus (contralateral) 3. External oblique of one side acting with opposite internal oblique (to be covered later)

Question 41

Action Grouping: Extension at the atlantooccipital joint

Answer 41

1. Longissimus capitis 2. Rectus capitis posterior major and minor 3. Semispinalis capitis 4. Splenius capitis 5. Superior oblique capitis 6. Trapezius

Question 42

Action Grouping: Lateral flexion/bending at the atlantooccipital joint

Answer 42

1. Longissimus capitis 2. Splenius capitis 3. Superior oblique capitis 4. Rectus capitis lateralis (to be covered later) 5. Sternocleidomastoid (to be covered later)

Question 43

Action Grouping: Ipsilateral rotation (right side muscles rotate head to right side and vice-versa with left side muscles)

Answer 43

1. Inferior oblique capitis 2. Longissimus capitis 3. Rectus capitis posterior major 4. Splenius capitis 5. Superior oblique capitis

Question 44

Action Grouping: Contralateral rotation (right side muscles act to turn head to left side)

Answer 44

1. Semispinalis capitis 2. Sternocleidomastoid (to be covered later)