Quiz 1 - Spinal Cord, Cervical, Brachial, Lumbar & Sacral

Question 1

Three regions in the central nervous system

Answer 1

Spinal
Brain stem and cerebellar
Cerebrum

Question 2

Spinal Region

Answer 2

Cross-section of the spinal cord reveals gray matter, forming a shape similar to the letter H surrounded by white matter

Question 3

Gray matter contains:

Answer 3

Neuronal cell bodies & synapses

Question 4

White matter contains:

Answer 4

Myelinated axons

Question 5

Dorsal horn has ____ ? And ventral horn has ____?

Answer 5

Sensory and motor

Question 6

Rootlets

Answer 6

Small bundles of nerve fibers (axons) attached to each side of the spinal cord
Merge to form roots (dorsal and ventral)

Question 7

Posterior (dorsal) root ganglion (somatic and visceral)

Answer 7

Sensory neuronal cell bodies

Question 8

Anterior (ventral) root

Answer 8

Motor/efferent fibers (somatic and visceral)

Question 9

Two parts in the Peripheral nervous system (PNS)

Answer 9

Motor (efferent) division: goes out of the PNS
Sensory (afferent) division: goes into the PNS

Question 10

Break down of Motor (efferent) division

Answer 10

Somatic nervous system
Autonomic nervous system (ANS)

Question 11

Somatic Nervous System

Answer 11

Motor innervation of all skeletal muscles

Question 12

Autonomic Nervous System

Answer 12

Motor innervation of smooth muscle, cardiac muscle, and glands

Question 13

Autonomic nervous system broken down into:

Answer 13

Sympathies division (fight or flight)
Parasympathetic division (rest & digest)

Question 14

Rootlets

Answer 14

Small bundles of nerve fibers (axons) attached to each side of the spinal cord
Merge to form roots (dorsal and ventral)

Question 15

Posterior (dorsal) root

Answer 15

Sensory / afferent fibers (somatic and visceral)

Question 16

Posterior (dorsal) root ganglion (spinal ganglion)

Answer 16

Sensory neuronal cell bodies

Question 17

Anterior (ventral) root

Answer 17

Motor / efferent fibers (somatic and visceral)

Question 18

Spinal Nerve

Answer 18

Posterior and anterior roots merge to form a spinal nerve

Question 19

Spinal nerve exits vertebral column through intervertebral or sacral foramina than branches into:

Answer 19

1. Posterior (dorsal) ramus
2. Anterior (ventral) ramus
3. Rami communicantes (communicating branches)

Question 20

Posterior (dorsal) ramus

Answer 20

Supplies motor and sensory fibers to the back region

Question 21

Anterior (ventral) ramus

Answer 21

Supplies motor and sensory fibers to antero-lateral trunk and limbs

Question 22

Thoracic region

Answer 22

Remain distinct and innervate a narrow strip forming the intercostal nerves that reach targets without networking with other spinal nerves (DO NOT form plexuses)

Question 23

Non-thoracic regions

Answer 23

Ventral rami converge to form networks called plexuses (bundle of rami)

Question 24

Rami communicantes (communicating branches)

Answer 24

2 branches that connect to sympathetic trunk:
1. Gray ramus communicans
2. White ramus communicans (only in T1-L2)

Question 25

Spinal Nerves

Answer 25

31 paired nerves - 8 cervical (C1-C8) *there are only 7 cervical vertebrae - 12 thoracic (T1-T12) - 5 lumbar (L1-L5) - 5 sacral (S1-S5) - 1 coccygeal (Co)

Question 26

Cervical nerves numbered by vertebra below level they emerge EXCEPT:

Answer 26

C1 spinal nerve (aka suboccipital nerve) emerges ABOVE C1 vertebra C8 exits below C7

Question 27

Spinal cord ends around vertebral level _____ as the _____.

Answer 27

L1/L2 Conus medullaris

Question 28

Thoracic, lumbar, and sacral nerves numbered by vertebra ____

Answer 28

ABOVE level they emerge Ex: what is the vertebra that travels below T8 and T9? - T8

Question 29

Spinal roots continually as the ______.

Answer 29

Cauda equina (horse tail)

Question 30

Plexuses

Answer 30

Composed of afferent and efferent fibers that arise from the merging of the anterior rami of spinal nerves - cervical (C1-C4) - brachial (C5 - T1) - lumbar (L1-L4) - sacral (L4-S4) - coccygeal (S5-Co)

Question 31

C1-C3 roots anastomose to form a loop called

Answer 31

Ansa cervicalis

Question 32

Ansa Cervicalis is made up of the:

Answer 32

Innervation 3 of the 4 infrahyoid muscles (“strap muscles”): the sternothyroid, sternohyiod and omohyoid

Question 33

What nerve roots make up the phrenic nerve and where does it innervate?

Answer 33

C3, C4, C5 (technically part of the brachial plexus) Innervation diaphragm

Question 34

Hypoglossal nerve (CNXII) and where does it innervate?

Answer 34

Not part of cervical plexus but contributes fibers to Ansa cervicalis Innervates tongue muscles

Question 35

Spinal accessory nerve (CN XI) and where does it innervate?

Answer 35

Medulla to C6 Fibers ascend spinal cord and emerge from jugular foramen Innervates trapezius (C3, C4) — elevates shoulders Innervates sternocleidomastoid (C2-C4) — turns head

Question 36

Branches of nerve roots that innervate neck muscles:

Answer 36

Longs capitis, longs colli, scalenes, levator scapulae, recuts capitis, longus capitis

Question 37

Cutaneous nerves carry _______

Answer 37

Sensory information from skin

Question 38

Lesser occipital nerve

Answer 38

Innervates the skin and the scalp posterior to the auricle

Question 39

Great auricular nerve

Answer 39

Innervates skin near concha auricle (outer ear) and external acoustic meats (ear canal)

Question 40

Transverse cervical nerve

Answer 40

Innervates anterior region of neck

Question 41

supraclavicular nerves

Answer 41

Innervate the skin above and below the clavicle

Question 42

Cervical Plexus

Answer 42

Ventral rami of C1-C4 Emerge beneath sternocleidomastoid muscle Innervates neck and head

Question 43

Brachial Plexus

Answer 43

Ventral rami of C5-T1 Located between anterior and middle scalene muscles in neck Supraclavicular part in posterior triangle of neck Infraclavicular part in axilla Innervates muscles, joints, skin of upper limb

Question 44

Brachial plexus contains:

Answer 44

Ventral rami (roots) Trunks Divisions Cords Terminal nerves

Question 45

Ventral Rami (Roots)

Answer 45

C5 - T1

Question 46

Trunks

Answer 46

Superior (C5 & C6) Middle (C7) Inferior (C8 & T1)

Question 47

Divisions

Answer 47

Each trunk has anterior and posterior division Posterior divisions combine to form posterior cord

Question 48

Cords

Answer 48

Named relative to axillary artery Lateral Posterior Medial

Question 49

Terminal nerves

Answer 49

Musculocutaneous Median Radial Ulnar

Question 50

Lumbar Plexus

Answer 50

T12 - L5 ventral rami Formed within psoas major muscle Motor and sensory innervation to pelvic girdle and lower limb

Question 51

Lumbar roots split to form anterior and posterior divisions in general:

Answer 51

Anterior supplies pelvis and medial thigh Posterior supplies anterior thigh

Question 52

Sacral Plexus

Answer 52

L4-S4 - L4, L5 via lumbosacral trunk (technically located in lumbar plexus) Rami split into anterior and posterior divisions

Question 53

Sacral plexus splits into

Answer 53

Leg, foot, gluteal and pelvic regions Anterior of piriformis muscle and posterior to internal iliac artery and vein

Question 54

Sacral spinal nerves split into

Answer 54

Anterior and posterior rami prior to emerging from anterior and posterior sacral foramina respectively

Question 55

Sciatic nerve

Answer 55

L4-S3 Contains common fibulae and tibial divisions - both travel together but remain separate in thigh - innervate posterior thigh muscles (hamstring)

Question 56

Sciatic nerve — divisions split at

Answer 56

Popliteal fossa

Question 57

Common fibular

Answer 57

Lateral and anterior compartments of the leg and dorsum of foot

Question 58

Tibial

Answer 58

Posterior compartment of leg and plantar side of foot

Question 59

Example Question: What is the vertebra that travels between T8 and T9?

Answer 59

T8

Question 60

Example Question: What is the vertebra that travels between C4 and C5?

Answer 60

C5

Question 61

Example Question: What are the spinal roots of the cervical plexus?

Answer 61

C1 - C4

Question 62

Example Question: The posterior cord has what divisions associated with it?

Answer 62

3 divisions