Clinical Anatomy of the Back

Question 1

Indications for imaging of the back? (7)

Answer 1

1. Trauma
2. Progressive Neuropathic Pain
3. Congenital Defects
4. Suspicion of infection
5. History of cancer
6. Fever
7. Progressive or prolonged back pain

Question 2

Attenuation of structures in an X-ray?

Answer 2

Metal (white) > Bone > Soft Tissue > Fat > Air (black)

Attenuation increases of a structure/material increases density

Question 3

Walls of blood vessels deep to superficial (3)?

Answer 3

Tunica initma: inner endothelial lining
Tunica media: middle smooth muscle layer, may contain elastic fibers
Tunica externa (adventitia): outer connective tissue layer

Tunica intima have valves in veins to prevent backflow

Question 4

Circulatory route (common)

Answer 4

Heart-Arteries-Arterioles-Capillary bed-Venules-Veins-Heart

Question 5

Circulatory Route: Portal System

Answer 5

Blood flows through consecutive capillary beds before returning to heart

Examples:
1. Between intestines/liver
2. Anterior Pituitary

Question 6

Arteriovenous Shunt

Answer 6

Artery flows directly into a vein.
Examples: fingers, toes, ears

Allows blood to bypass exposed areas during cold. For DECREASE heat loss

Question 7

Anastomosis

Answer 7

Union of branches of two or more vessels

Venous: allows for alternate drainage of organs

Arterial: collateral circulation

Question 8

Where does the R side of the body drain lymph?

Answer 8

R lymphatic duct

Question 8

Where does the R side of the body drain lymph?

Answer 8

R lymphatic duct

Question 9

Where does most of the body drain lymph into?

All Left and lower R

Answer 9

Thoracic duct

Question 10

Where do Somites form from?

Answer 10

Paraxial mesoderm

Develop alongside the developing neural tube as paired segments

Question 11

What are the two major parts of the somites?

Answer 11

1. Sclerotome: verterbral column
2. Dermomyotome:
   Dermatome: skin
   Myotome: muscles of trunk and limb

General Concept: dermatome and myotome develop from a single segment and is invervated by a single spinal nerve

Question 12

Where does spinal nerves C1 and C8 exit?

Answer 12

Above same number vetebra

C8 exits above T1 as there is no C8 vertebra

Question 13

Where do spinal nerves C2-C7, T1 to end of cord exit?

Answer 13

Below their respective vetebra

Question 14

Somatic Plexuses

Answer 14

Cervical: C1-C5
Brachial: C5-T1
Lumbar: L1-L4
Sacral: L5-S4

Question 15

General concept for afferent sensory fibers

3 neuron chain

Answer 15

1. First order: arises at the organ (or muscle) and has two processes. One on either side of the cell body. Cell body is located outside of CNS (DRG). NO SYNAPSE HERE
   -Central process enters the CNS and synapses on the next neuron (FIRST SYNAPSE)
2. Second order: arises from the gray horn of the spinal cord or brainstem nucleus and synapses in the thalamus
3. Third order: arises from the thalamus and ends in the cortex

Olfactory does not follow the pattern

Question 16

General concept of sympathetic efferent fibers

Target tissue

Answer 16

Lateral grey horn of T1-L2
Ventral roots–>ventral rami–> white rami communicants–> grey rami commmunicants

1. Synapse and exit through grey rami communicants
2. Travel up or down the chain to synapse in a different location
3. Exit without synapsing=splanchnic nerves (directly to organ)

Target tissues: Heart, BV, Organs, SM, Glands

Question 17

General Concept of Parasympathetic efferent fibers

Brainstem

Answer 17

Cranial nerve–>Parasympathetic Ganglion

Target tissue: Visceral motor fibers
1. Constrictor pupillae
2. Lacrimal gland
3. Salivary gland
4. Minor glands along the mucous membrane

Question 18

General Concept of Parasympathetic efferent fibers

Spinal Cord S2-S4

Answer 18

Ventral roots–>ventral rami–> pelvic splanchnic nerves–>ganglia in organ walls

Target tissue: BV, Organs, SM, Glands

Question 19

Dermatomes

Answer 19

C6: Thumb
T4: Nipple
T10: Umbilicus
L5: Big Toe
S2: Back of Thigh

Question 20

Referred Pain definition?

Answer 20

Pain felt in an area that is different to where the injury occurred

Question 21

Adult/Newborn Conus Medullaris ends at…?

Answer 21

Adult: L1-L2
Newborn: L3-L4

Question 22

Pia Mater derived from?

Creates what (2)

Answer 22

Derived from neural crest cells

Creates: Denticulate Ligament
Filum Terminale

Question 23

What is in the epidural space?

Answer 23

Nerves and Batson’s plexus

Batson’s Plexus has no valves-infections can metastasize

Question 24

What is in the subarachnoid space?

Answer 24

CSF

Question 25

Why perform a fasciotomy?

Answer 25

Relieve increasing pressure in MSK compartments

Question 26

Importance of Fascia? (4)

Answer 26

1. Interconnects all structures of the body-contains **collagen fibers** in sheets orientated in different directions 2. Allows for **sliding** of the muscular structure 3. **Reduce friction** 4. **Increase force** of contraction

Question 27

Splenius Muscle (Function, innervation, blood supply) | Intrinsic Back Muscles

Answer 27

**Fx:** Bilateral: extension of neck Unilateral: ipsilateral lateral flexion and rotation of vertebral column **Innervation:** Posterior (Dorsal) Rami of Cervical Spinal Nerves **Blood Supply:** Deep Cervical Artery/Occipital Artery

Question 28

Erector Spinae Muscle Group (Function, innervation, blood supply) | Intrinsic Back Muscles

Answer 28

**Fx:** Bilateral: extension of vertebral column and head; during flexion of back allow for control movement by gradually lengthening fibers Unilateral: ipsilateral flexion of vertebral column **Innervation:** Posterior (Dorsal) Rami of Spinal Nerves **Blood Supply:** Vertebral artery, deep cervical artery, occipital artery, transverse cervical artery, Posterior Intercostal Artery, Lumbar Artery, Lateral Sacral Artery

Question 29

Semispinalis Muscle (Function, innervation, blood supply) | Intrinsic Back Muscles

Answer 29

**Fx:** Bilateral: extends head, cervical and thoracic regions of vertebral column Unilateral: Contralateral rotation of the vertebral column contralaterally **Innervation:** Posterior (Dorsal) Rami of Spinal Nerves **Blood Supply:** Deep Cervical Artery, Posterior Intercostal Artery, Subcostal Artery, Lumbary Artery

Question 30

Multifudus (Function, innervation, blood supply) | Intrinsic Back Muscles

Answer 30

**Fx:** Stabilizes vertebrae **Innervation:** Posterior (Dorsal) Rami of Spinal Nerves **Blood Supply:** Deep Cervical, Posterior Intercostal Artery, Subcostal Artery, Lumbar Artery

Question 31

Rotatores (Function, innervation, blood supply) | Intrinsic Back Muscles

Answer 31

**Fx:** Stabilizes vertebrae and assist with local extension and rotatory movement of vertebral column **Innervation:** Posterior (Dorsal) Rami of Spinal Nerves **Blood Supply:** Deep Cervical, Posterior Intercostal Artery, Subcostal Artery, Lumbar Artery

Question 32

Interspinales Muscle (Function, innervation, blood supply) | Intrinsic Back Muscles

Answer 32

**Fx:** Posturual and stabilizes vertebrae **Innervation:** Posterior (Dorsal) Rami of Spinal nerves

Question 33

Intertransversarii Muscle (Function, innervation) | Intrinsic Back Muscle

Answer 33

**Fx:** Postural and stabilizes vertebrae **Innervation:** Posterior (Dorsal) Rami of Spinal Nerves

Question 34

Levatores Costarum (Function, innervation) | Intrinsic Back Muscle

Answer 34

**Fx:** Elevation of ribs (respiratory function)-assist with lateral flexion of vertebral column **Innervation:** Posterior (Dorsal) Rami of Spinal Nerves

Question 35

Trapezius (Function, innervation, blood supply) | Superficial Back Muscle

Answer 35

**Fx:** Assists in rotating scapula during abduction of humerus above horizontal 1. Upper: elevate scapula 2. Middle: adduct the scapula 3. Lower: depress scapula **Innervation:** Accessory nerve (CN XI), cervical spinal nerves C3/C4 (proprioception) **Blood Supply:** Superficial branch of transverse cervical artery

Question 36

Latissimus Dorsi (Function, innervation, blood supply) | Superficial Back Muscle

Answer 36

**Fx:** Extends, adducts, and medially rotates humerus **Innervation:** Thoracodorsal nerve (C6-C8) **Blood Supply:** Thoracodorsal artery

Question 37

Levator Scapulae (Function, innervation, blood supply) | Superficial Back Muscle

Answer 37

**Fx:** Elevate scapula **Innervation:** C3-C4, Dorsal scapular nerve **Blood Supply:** Transverse and ascending cervical arteries

Question 38

Rhomboid Major/Minor (Function, innervation, blood supply) | Superficial Back Muscle

Answer 38

**Fx:** Retract (adduct) and elevate scapula **Innervation:**Dorsal scapular nerve (C4-C5) **Blood Supply:** Deep branch of transverse cervical artery and/or dorsal scapular artery

Question 39

Serratus Posterior Superior (Function, innervation, blood supply) | Superifical Back Muscle

Answer 39

**Fx:** Elevate ribs 2 to 5 **Innervation:** Anterior rami of upper thoracic (intercostal) nerves T2-T5 **Blood Supply:** Segmental supply through intercostal arteries

Question 40

Serratus Posterior Inferior (Function, innervation, blood supply) | Superficial Back Muscle

Answer 40

**Fx:** Depress ribs 9-12 and may prevent lower ribs from elevating when diaphragm contracts **Innervation:** Anterior rami of lower thoracic (intercostal) nerves T9-12 **Blood Supply:** Segmental supply through intercostal arteries

Question 41

Supraspinatus (Function, innervation, blood supply) | Superficial Back Muscle

Answer 41

**Fx:**Rotator cuff muscle; initation of abduction of the humerus to 15 degreeas at the shoulder joint **Innervation** Suprascapular nerve (C5-C6) **Blood Supply:** Suprascapular Artery

Question 42

Infraspinatus (Function, innervation, blood supply) | Superficial Back Muscles

Answer 42

**Fx:** Rotator Cuff Muscle; lateral rotation of the humerus at the shoulder joint **Innervation:** Suprascapular nerve (C5-C6) **Blood Supply:** Suprascapular and Circumflex Scapular Arteries

Question 43

Teres Minor (Function, innervation, blood supply) | Superficial Back Muscle

Answer 43

**Fx:** Rotator Cuff Muscle; Lateral rotation of the arm at the shoulder joint **Innervation:** C3-C4 Dorsal Scapular Nerve **Blood Supply:** Posterior Humeral Circumflex Artery

Question 44

Teres Major (Function, innervation, blood supply) | Superficial Back Muscles

Answer 44

**Fx:** Medial Rotation and extension of the arm at the glenohumeral joint **Innervation:** Axillary Nerve (C5/C6) **Blood Supply:** Posterior Circumflex Artery and Thoracodorsal branch of the Subscapular Atery

Question 45

Triceps Muscle-Long Head (Function, innervation, blood supply) | Superficial Back Muscle

Answer 45

**Fx:** Extension of the forearm at the elbow joint; accessory adductor and extensor of the arm at the glenohumeral joint **Innervation:**Radial Nerve (C6-C8) **Blood Supply:** Deep Brachial Artery (Profunda Brachii)

Question 46

Hilton's Law

Answer 46

A joint is innervated by a nere innervating the muscle moving the joint. This nerve also innervates the skin over the joint

Question 47

Lymph drainage: Occipital, Deep Cervical, Axillary (posterior), Paravertebral Nodes

Answer 47

**Occipital, Deep cervical, Axillary**: Skin of the back and neck drains **Paravertebral**: muscles of the back

Question 48

Triangle of Auscultation Borders

Answer 48

Prime Pulmonary Auscultation Inferior: Superior border of Latissimus Dorsi Medial: Lateral border of Trapezius Lateral: Medial Border of Scapula

Question 49

Triangle of Petit | Inferior Lumbar Triangle/Lumbar Triangle

Answer 49

Inferior: Iliac Crest Posterior: Latissimus Dorsi Anterior: External Oblique Floor: Internal Oblique and Transversus Abdominus Bulge in the lumbar region-may be unilateral/bilateral. | Rare type of hernia-aquired or congenital

Question 50

How to Read and X-Ray of the Back Region

Answer 50

Lateral View: Three Column approach Anterior-Posterior View: Lateral Lines (2) and Spinous Line

Question 51

Why use an open mouth view? (xray)

Answer 51

ALignment of odontoid process with C1 lateral masses

Question 52

T2 vs T1 MRI

Answer 52

T2 hyperintensifies water "H**2**O"

Question 53

2 "Pop" in an LP

Answer 53

First: Ligamentum flavum Second: Dura mater

Question 54

Supracristal line for LP

Answer 54

Palpate for the top of the iliac crest and imagine a horizontal line connecting the two crests -L4-L5

Question 55

What ligaments are damaged in a whiplash injury?

Answer 55

Hyperexention injury of the neck **Anterior longitudinal ligament** (hyperextension) **Nuchal ligament **(hyperflexion) Symptoms: headache, neck pain radiating to shoulders, upper back pain, dizziness, and neurological signs of concussion | This is a noncontact applied force. Contact injuries can have same S/S

Question 56

Transverse Ligament Rupture

Answer 56

1. Can be a result of whiplash 2. Causes an increase in flexion angle of the skull and cervicle vertebrae 3. Disolocation of the dens into vertebral canal leading to **compression of spinal cord**-->cardiorespiratory issues. ## Footnote Pt could present, unconscious, paraplegic, incontinent

Question 57

Dens Fracture | Type I,II,III

Answer 57

Dens # can occur w/ both flexion or extension injuries Avulsion of dens posteriorly can compress spinal cord--> +ve neurological symptoms 1. Neck pain 2. Numbness in limbs 3. Quadriplegia 4. Respiratory arrest d/t diaphragm paralysis Type I: # above mid line of dens Type II: # horizontal line including all of dens Type III: # extends into vertebral body

Question 58

Jefferson Fracture

Answer 58

Burst fracture of the C1 vertebrae **Axial loading injury** --> lateral masses move outward and could cause transverse ligament damage leading towards respiratory issues. **Highly unstable #**

Question 59

Describe what a disc herniation is

Answer 59

Increase in size of nucleus pulposus. Causes a bulge into the spinal cord

Question 60

Spondylosis

Answer 60

Arthritis that develops in the facet joints-means bone spurs are forming

Question 61

Spondylolysis

Answer 61

Stress fracture of the pars interarticular of lumbar vertebrae. +/- neuro symptoms Unilateral or bilateral | Need an oblique view of xray to visualize

Question 62

Spondylolisthesis

Answer 62

**Anterior slippage** which can be a result in narrowing of intervertebral foarmina-->spinal nerve impingements-->neurological S/S If occuring w/ spondylolysis it is called **Spondylolytic spondylolisthesis**

Question 63

What is the one "pop" felt for a epidural?

Answer 63

Ligamentum flavum

Question 64

What is Sacral Analgesia? | Caudal Anesthesia

Answer 64

1. Provides anesthesia to the caudal nerve roots 2. Needle inserted into **sacral hiatus** 3. Done under U/S guidance

Question 65

What is the difference between Sacralization/Lumbarization?

Answer 65

**Sacrilization:** is when there is a **partial fusion of lumbar to sacrum** **Lumbarization:** is there is a **partial separation of S1 from the sacrum**

Question 66

What is Klippel Feil?

Answer 66

Congenital fusion of cervical vertebrae leading to a shorten neck. Physical features: shortened neck, decreased ROM, low hairline Associated w/ **scoliosis** and **hemivertebrae**(half of a vertebrae doesn't form and leads to scoliosis)