Part 1 Chiropractic Boards: Spinal Anatomy -- PNS, ANS, & Special Senses

What are the cells of the PNS that form myelin?

Schwann cells

NOTE: "PS" I love you my SWAN

What are gaps in the myelin sheath between schwann cells?

Nodes of Ranvier

What is included in the PNS?

Cranial & spinal nerves (& their ganglia)

What is a group of neuron cell bodies in the PNS?

Ganglia

T/F: Peripheral nerves ("Nerve") are mostly myelinated axons

TRUE

What is a single axon in a peripheral nerve?

Nerve fiber

What type of cell is found in posterior root ganglia? What type of cells are found in the retina & sensory ganglia of cochlear & vestibular nerves?

Unipolar cells

Bipolar cells (think hearing, balance, & vision)

What are the 4 cutaneous (superficial) branches of the cervical plexus?

1) Lesser occipital

2) Greater auricular

3) Transverse cervical

4) Supraclavicular (anterior, middle, & posterior)

NOTE: none are dual (sensory & motor); superficial are ALL sensory

What are the spinal roots for the Lesser Occipital, Greater Auricular, and Transverse cervical nerves?

C2 & C3

What is the spinal roots for the Supraclavicular (anterior, middle, & posterior)?

C3 & C4

What are the structures served by the lesser occipital nerve?

Posteriolateral neck

What are the structures served by the greater auricular nerve?

Ear & Parotic gland

What are the structures served by the transverse cervical?

Anterior & Lateral neck

What are the structures served by the Supraclavicular (ant, mid, & post)?

Shoulder & anterior chest

What are the 3 motor branches (deep) of the cervical plexus?

1) Ansa cervicalis (superior & inferior roots)

2) Segmental branches

3) Phrenic

NOTE: None are dual (sensory & motor); deep branches all motor

What are the spinal roots for the ansa cervicalis (superior & inferior roots)?

C1-C4

What are the spinal roots for the segmental branches?

C1-C5

What are the spinal roots for the Phrenic nerve?

C3, 4, 5

(NOTE: C 3, 4, 5 keeps the diaphragm ALIVE)

What are the structures served by the Ansa cervicalis (sup & inf roots)?

Motor -

Geniohyoid & infrahyoid muscles of neck

What are the structures served by the segmental branches?

Motor -

Neck & scalenes, levator, traps, SCM

What are the structure served by the phrenic nerve?

Diaphragm

NOTE: C 3, 4, 5 keeps the diaphragm alive!

What are the 6 nerves of the lumbar plexus?

1) Femoral

2) Obturator

3) Lateral femoral cutaneous (lat fem cut)

4) Iliohypogastric

5) Ilioinguinal

6) Genitofemoral

NOTE: only nerves of lumbar plexus with motor functions are femoral & obturator nerves

What are the spinal roots for the Femoral and Obturator nerves?

L2 - L4

What are the spinal roots for the lateral femoral cutaneous (lat fem cut) nerve?

L2 & L3

What are the spinal roots for the iliohypogastric & Ilioinguinal nerves?

L1

What are the spinal roots for the genitofemoral nerve?

L1 & 2

What are the sensory structures served by the femoral nerve? The motor structures?

Sensory

- Thigh, leg, foot, hip, knee joint

Motor

- Ant thigh, psoas, pectineus, iliacus

What are the sensory structures served by the obturator nerve? The motor structures?

Sensory

- medial thigh, hip joint

Motor

- Adductors, gracilis, obturator externus

What are the sensory structures served by the lateral femoral cutaneous (lat fem cut)? The motor structures?

Sensory

- lateral thigh, branches to peritoneum

Motor

- NONE

What are the sensory structures served by the iliohypogastric? The motor structures?

Sensory

- lower abdomen, lower back & hip, anterolateral abdominal wall, pubic region

Motor

- NONE

What are the sensory structures served by the ilioinguinal? The motor structures?

Sensory

- external genitalia, thigh, & abdominals

Motor

- NONE

What are the sensory structures served by the genitofemoral? The motor structures?

Sensory

- scrotum, labia, thigh, cremasteric

Motor

- NONE

What are the 8 nerve branches of the Sacral Plexus?

1) Sciatic nerve

2) Tibial

3) Common peroneal (aka fibular)

4) Superficial Peroneal (aka fibular)

5) Deep peroneal (fibular)

6) Superior gluteal

7) Inferior gluteal

8) Pudendal

NOTE: only nerves with sensory components are Tibial, Common peroneal (fibular), and Pudendal!

What are the spinal nerves for the Sciatic and Tibial nerve?

L4 - S3

What are the spinal nerves for the Common peroneal (fibular), Superficial peroneal (fibular), and the deep peroneal (fibular)?

L4 - S2

What are the spinal nerves for the superior gluteal nerves?

L4, L5, S1

What are the spinal nerves for the inferior gluteal nerves?

L5 - S2

What are the spinal nerves for the Pudendal nerves?

S2, 3, 4

(NOTE: S 2, 3, 4 keeps the penis off the floor)

What are the sensory structures served by the Sciatic nerve? Motor structures?

Sensory -

NONE

Motor -

Tibial & Common peroneal

What are the sensory structures served by the Tibial nerve? Motor structures?

Sensory -

Posterior leg & foot

Motor -

All muscles of the back of thigh, leg, & foot

What are the sensory structures served by the Common Peroneal (fibular)? Motor structures?

Sensory

- anterior leg & dorsum foot

Motor

- peroneals, tibialis ant, extension of toe

What are the sensory structures served by the Superficial peroneal (fibular)? Motor structures?

Sensory

- NONE

Motor

- Lateral compartment of leg

What are the sensory structures served by the Deep peroneal (fibular)? Motor structures?

Sensory

- NONE

Motor

- Anterior compartment of leg

What are the sensory structures served by the Superior Gluteal nerve? Motor structures?

Sensory

- NONE

Motor

- Gluteus medius, minimus, & TFL

What are the sensory structures served by the Inferior Gluteal? Motor structures?

Sensory

- NONE

Motor

- Gluteus maximus

What are the sensory structures served by the Pudendal nerve? Motor structures?

Sensory

- Muscles of perineum

Motor

- External anal sphincter

The brachial pe=lexus is named according to what structure?

Axillary artery

What is the divisional order of the branchial plexus?

Roots

Trunks

Divisions

Cords

Branches

(NOTE: Rugby Team Drinks Cold Beer)

What are the 5 branches of the brachial plexus? What cords are each a part of?

1. Musculocutaneous (Lateral cord)

2. Ulnar (Medial cord)

3. Median (Lat & Med cord)

4. Radial (Posterior cord)

5. Axillary (Posterior cord)

(NOTE: pneumonic is MARMU)

What roots make up the brachial plexus?

C5-T1

What spinal nerve roots for the upper trunk of the brachial plexus? Middle trunk? Lower trunk?

Upper trunk = C5 & C6

Middle trunk = C7 alone

Lower trunk = C8 & T1

What are the two divisions that the brachial plexus divides in to?

Anterior & Posterior division

The lateral cord is made up from the __________ division of the _____________ trunks and contains what spinal nerve root fibers?

Anterior division

Upper & Middle trunks

C5, 6, 7

The medial cord is made up from the _________ division of the __________ trunk and contains what spinal nerve root fibers?

Anterior division

Lower trunk

C8 & T1

NOTE: remember MediaL cord and MediaN nerve

The posterior cord is made up from the ___________ division of ________________. and contains fibers from what spinal nerve roots?

Posterior division

ALL THREE CORDS

C5 - T1

What 2 nerve comes directly off the spinal nerve roots of the brachial plexus?

1) Long thoracic (C5, 6, 7)

2) Dorsal scapular nerve

What 2 nerves come fof the upper trunk of the brachial plexus?

1) Suprascapular

2) Nerve to subclavius

What 3 nerves come off the Lateral cord of the brachial plexus?

1) Lateral pectoral

2) Musculocutaneous

3) Part of median (Median and Lateral cord)

What are 5 nerves coming off the medial cord of the brachial plexus?

1) Medial pectoral

2) Medial brachial cutaneous

3) Medial antebrachial cutaneous

4) Ulnar

5) Part of median (Medial & Lateral cord)

What are the 5 nerves coming off the Posterior cord of the brachial plexus?

1) upper subscapular

2) lower subscapular

3) thoracodorsal

5) axillary

5) radial

What is a pneumonic for remembering the functions of the 12 cranial nerves?

I - Some

II - Say

III - Marry

IV - Money

V - But

VI - My

VII - Brother

VIII - Says

IX - Big

X - Brains

XI - Matter

XII - Most

NOTE: S = Sensory; M = motor; B = both

(Some Say Marry Money But My Brother Says Big Brains Matter Most)

What is the pneumonic for remembering the foramina of the 12 cranial nerves?

Come On SOFia SOFia SOFia, ROll OVer SOFia, I AM In A Mood (for) JUGs JUGs JUGs. Hello!

C = cribiform plate

O = optic canal

SOF = Superior Orbital Fissure

RO = Foramen Rotundum

FO = Foramen Ovale

SOF = Superior Orbital Fissure

I AM & In A Mood= Internal Auditory meatus

JUGs = Jugular Foramen

H = Hypoglossal canal

What are all the Cranial Nerves (I - 12)? Which are Sensory, Motor, or Both?

I = Olfactory (S)

II = Optic (S)

III = Oculomotor (Constrictor pupillae; parasympathetic; M)

IV = Trochlear (M)

V = Trigeminal (V1 Ophthalmic; V2 Maxillary; V3 Mandibular; B)

VI = Abducens (M)

VII = Facial (B)

VIII = Vestibular-Cochlear (S)

IX = Glossopharyngeal (B)

X = Vagus ("wanderer"; B)

XI = Accessory (M)

XII = Hypoglossal (M)

NOTE:

Sensory = 1, 2, 8

Motor = 3, 4, 6, 11, 12

Both = 5, 7, 9, 10

What is the function of the CN I?

Sensory

- Smell

What is the foramen/exit/path for CN I (Olfactory)?

Cribiform plate

What is the function of CN II?

Sensory

- Vision

What is the foramen/exit/path of CN II (Optic)?

Optic Canal

What is the function of CN III?

Motor

- Eye muscles (EXCEPT lateral rectus & superior oblique)

-- opens eyes

SO4 + LR6 / 3

What is the Nuclei/ganglion of CN III?

Edinger Westphal

What is the function of CN IV?

Motor

- Superior Oblique

SO4 + LR6 / 3

What is the function of CN V?

Sensory

- Face & tongue

Motor

- Mastication

What are the 3 branches of the Trigeminal?

V1 - ophthalmic

V2 - maxillary

V3 - mandibular

What is the nuclei/ganglia of the CN V (Trigeminal)?

Trigeminal Ganglia (Gasserian Semilunar Ganglia)

What is the function of CN VI?

Motor

- Lateral rectus

SO4 + LR6 / 3

What is the foramen/exit/path of CN IV (Trochlear), CN V (Trigeminal), & CN VI (Abducens)? What are the 2 additional paths/exits for CN V?

Superior Orbital Fissure (SOF)

CN V + Foramen rotundum & Foramen Ovale

NOTE: Remember CN 4, 5', 6 is SOF

' = + Foramen rotundum & ovale

What is the function of CN VII?

Sensory

- Anterior 2/3 taste (Sweet, Sour, Salty!)

Motor

- Facial expression (closes eye)

NOTE: Abducens opposite function (closes eye; CN 6) of Oculomotor (which opens eye; CN 3)

What is the foramen/exit/path of CN VII (Facial)?

Internal Auditory meatus

- exits through Styloid Mastoid

What is the Nuclei/ganglion for CN VII (Facial)? Through what branch does this interact with?

Superior Salivary

-- branch of chorda tympani

What is the function of CN VIII?

Sensory

- balance & hearing

What is the foramen/exit/path of CN VIII (Vestibular-Cochlear)?

Internal Auditory meatus

NOTE: Same as Facial (CN 7), except facial exits through styloid mastoid

What nuclei/ganglion is involved with CN VIII (Vestibular-Cochlear)?

Vestibular ganglion (of Scarpa)

What is the function of CN IX?

Sensory

- Posterior 1/2 taste (BITTER)

Motor

- Secretion of Parotid

NOTE: Opposite of facial for taste; Facial (CN 7) does anterior 2/3 w/ salt, sweet, and sour.

What nucleus/ganglion in involved with CN IX (Glossopharyngeal)?

Nucleus Ambiguous (Inferior Salivary)

What is the function of CN X?

Sensory

- Bitter taste in EPIGLOTTIS

- External auditory meatus

Motor

- Pharynx & Larynx

NOTE: The 3 CN that are involved in taste -->

Facial (7) = Anterior 2/3 of tongue (sweet, sour, salty)

Glossopharyngeal (9) = Posterior 1/3 of tongue (bitter)

Vagus (10) = Epiglottis (bitter)

What is the nucleus/ganglion involved with CN X (Vagus)?

Parasympathetic Dorsal Motor Nucleus

What is the function of CN XI?

Motor

- SCM & Trapezius

What nucleus/ganglion is involved with CN XI (Accessory)?

Nucleus Ambiguous

What is the foramen/exit/path of CN IX (glossopharyngeal), CN X (vagus), and CN XI (accessory)?

Jugular Foramen

NOTE: remember CN 9, 10, 11 all Jugular Foramen

What is the function of CN XII?

Motor

- Tongue movement

What is the foramen/exit/path of CN XII (Hypoglossal)?

Hypoglossal canal

NOTE: hypoglossal goes together w/ name of CN!

What is the nucleus/ganglion associated with CN XII (Hypoglossal)?

Hypoglossal nuc/gang

What is the smallest CN?

Trochlear (CN IV)

What is the only CN that does NOT synapse in the thalamus?

CN I (Olfactory)

What is a chronic pain disorder that involves sudden attacks of severe facial pain, affecting the CN that provides feeling/nerve signaling to parts of head and face? What CN does this affect?

Trigeminal Neuralgia (tic douloureux)

CN V (trigeminal nerve)

What is the largest CN?

Trigeminal nerve (CN V)

What is an idiopathic episode of facial muscle weakness/paralysis, with pain/discomfort usually occurring on one side of the face/head? What CN does this affect?

Bell's palsy

CN VII (Facial)

Uvula deviation is associated with what CN lesion? What way does the uvula deviate?

Vagus (CN X)

Uvula deviates AWAY from lesion

Tongue deviation is associated with what CN lesion? What way does the tongue deviate?

CN XII (hypoglossal)

Tongue deviates TOWARD lesion

NOTE: Tongue TOWARD

What two bones form the Jugular Foramen? Foramen lacerum?

Temporal & Occipital (jugular foramen)

Temporal & Sphenoid (foramen lacerum)

What 4 CN is associated with parasympathetics? Which makes up 90% of the body?

CN 3, 7, 9, 10

CN 10 = 90% of body