815-WK 8: Head and Neck

Anterior and lateral neck muscles are what?

-Platysma

-Sternocleidomastoid

-Scaleni Muscles (Anterior, middle, posterior)

What is in front of the brachial plexus

Anterior scalene

What are the regions of the neck?

Posterior Triangle

Anterior Triangle

Posterior triangle borders

-Anterior border

-Posterior border

-Inferior border

-Base

-Apex

Posterior triangle anterior border

Posterior border of SCM muscle

Posterior triangle posterior border

Anterior border of trapezius muscle

Posterior triangle inferior border

Middle third of clavicle

Posterior triangle base

Clavicle

Posterior triangle apex

Superior nuchal line where SCM and trapezius meet

Posterior triangle contains

Accessory nerve (CN XI)

Anterior Triangle has what borders?

-Medial border

-Lateral border

-Superior border

-Apex

-Base

Anterior triangle medial border

Anteromedian line of neck

Anterior triangle lateral border

Anterior border of SCM

Anterior triangle superior border

Inferior border of mandible

Anterior triangle apex

Jugular notch of sternum

Anterior triangle base

Inferior border of mandible and a line from angle of mandible to mastoid process

Cervical plexus location

Ventral rami of C1-C4

Cervical plexus parts

Cutaneous and muscular and muscular branches

Cervical plexus Cutaneous

Lesser occipital

C2, C3

Cervical plexus cutaneous

Great auricular

C2, C3

Cervical plexus cutaneous

Transverse cervical

C2, C3

Cervical plexus cutaneous

Supraclavicular

C3, C4

Cervical plexus muscular

Ansa cervicalis

C1, C2, C3

Cervical plexus muscular

Superior root of ansa cervicalis

C1, C2

Cervical plexus muscular

Inferior root of ansa cervicalis

C2, C3

Cervical plexus muscular

Phrenic

C3, C4, C5

Dermatomes of the head and neck

Trigeminal nerve (CN V)

Cervical plexus

Dorsal rami (C3-C5)

Greater occipital nerve

Trigeminal nerve

-Ophthalmic nerve (V1)

-Maxillary nerve (V2)

-Mandibular nerve (V3)

Cervical plexus

-Transverse cervical

-Great auricular

-Lesser occipital

Dorsal rami

C3-C5

Greater occipital nerve

Spinal nerve of C2

Punctum nervosum (Erb’s Point) location

-Located on the posterior border of the SCM

-Midway between the origin and insertion

All four cutaneous branches of the cervical plexus pierce

The investing layer of the deep cervical fascia and emerge from the posterior border of SCM

Together supply cutaneous innervation to the neck and head

The four nerves that diverge from Erb’s point are

-Lesser occipital nerve

-Greater auricular nerve

-Transverse cervical nerve

-Supraclavicular nerves

Carotid sheath

-Common carotid

-Internal jugular vein

-Ansa cervicalis

-Vagus nerve (CN X)

Carotid arteries

Common carotid

-Internal (posterior) carotid

-External (anterior) carotid

Jugular veins

-External jugular

-Internal jugular

-Anterior jugular

-Communicating jugular

Locations of hyoid bone

C3

Suprahyoid muscles location

Above hyoid muscle

Suprahyoid muscles

-Digastric

-Stylohyoid

-Mylohyoid

-Geniohyoid

Mylohyoid is only visible when?

When you reflect the geniohyoid

Infrahyoid muscles “Strap muscles”

-Thyrohyoid

-Omohyoid (superior belly)

-Sternohyoid

Prevertebral muscles (in front of spine)

-Longus capitis

-Longus colli

Longus capitis location

More lateral and continuation of anterior digastric

Axial skeleton parts

-Cranium

-Face

-Vertebrae (25 bones)

-Sternum

-Ribs

-Inner ear

-Hyoid

Vertebral processes

Spinous and transverse

Vertebral arch location and parts

-Location: posterior portion of the vertebra

Parts:

-Pedicles and laminae

-Intervertebral foramina

-Force transmission

-Spinal nerve

Vertebral arch pedicles

Helps form the intervertebral foramen

Vertebral arch intervertebral foramina

Passage of neurovascular and lymph

Vertebral arch force transmission

From posterior to body

Vertebral arch spinal nerve

Lack significant epineurium

Vertebral body load bearing design

-Longitudinal loads

-Cortical shell

-Cancellous cavity

Vertebral body trabeculae (vertical and transverse)

-Strength

-Resilience

-Passage of vascular structures

Lamina locations

Articular processes and has pars interarticularis

Lamina functions

-Protection

-Muscular attachment

-Load transmission

Pars interarticularis

-Aka Scotty dog

-Contains spondylosis and spondylolisthesis

Intervertebral disc structure

-Nucleus pulposus (anterior)

-Annulus fibrosus (posterior)

Intervertebral disc function

-Binds bodies

-Permits motion

-Transmits loads

Intervertebral disc motions (compressive loads)

-Forward bending (FB-flexion)

-Backward bending (BB-extension)

-Side bending (SB)

-Rotation= torsion

-Rotation/bending creates shear stresses

Nucleus pulposus function

-Imbibition

-Nutrition

-Transmits forces

-Equalizes stress

-Motion

Imbibition

The absorption of one substance by another (like the uptake of water by a plant)

Nucleus pulposus structure

-Loose network of collagen/reticular mesh in a mucoprotein gel that is rich in muchopolysaccharies

-H20= 70-90%

-Ball bearing

-Dehydration occurs with age

Glycosaminoglycans

-GAGs

-Highly polar and attract water

-Used as lubricant or as a shock absorber

-Long unbranched polysaccharides

Annulus fibrosus structure

-Fibrocartilaginous rings

-Oblique orientation of fibers; angle varies (30 degrees vertical)

-High concentration of type 1 collagen

-Attach to endplates and body

Annulus fibrosus functions

-Contains nucleus

-Stabilization

-Allows motion

-Minimal shock absorption

Annulus fibrosus neural supply

Sinuvertebral nerves from grey rami

Vertebral (cartilaginous) end plate structure

-Hyaline structure

-Proteoglycans and collagen like a “mini disc”

Vertebral (cartilaginous) end plate functions

-Protects vertebral body from weight transmission

-Attachment of annulus

-NUTRITION VIA FLUID EXCHANGE BETWEEN THE DISC AND BODY

Schmorl’s nodes

Jelly donut example

FB goes posterior and BB goes anterior

Zygapophyseal joints (facets) structure

-Superior and inferior articular facets

-Transverse costal facet

-Costovertebral demi-facet (2-10)

Zygapophyseal joints (facets) synovial joints

-Hyaline cartilage

-Capsule

-intra-articular menisci

Zygapophyseal joints (facets) functions

-Guides motion

-Stability

Zygapophyseal joints (facets) facet angles

Increases from L1-L5

Zygapophyseal joints (facets) source of pain

Innervated from 2-3 levels

L1-L2 angle

25

L2-L3 angle

28

L3-L4 angle

37

L4-L5 angle

48

Spinal nerves roots

Dorsal root

Ventral root

Dorsal root

-Dorsal root ganglia

-Sensory fibers

Ventral root

-Motor

-Some sensory

-Preganlionic

-Sympathetic

-Efferent fibers

Spinal nerves roots join where? and divides into what?

-Roots join in the intervertebral foramen

-Each divides into a larger ventricular ramus and shorter dorsal ramus

Spinal cord terminates where?

Where is the location

Between L1-L2 as the conus medullaris

Spinal cord contained within thecal/dursal sac

Spinal cord structure

-Fibrous band that extends from the conus medullaris to the periosteum of the coccyx is known as the filium terminale

Cauda equina

Roots of lumbar, sacral, and coccygeal spinal nerves within the cal sac

How many cervical vertebrae are there

7

Cervical vertebrae unique structure

•Transverse foramen which houses the vertebral artery

•Spinous processes angle sharply down and are frequently bifid

C1

Atlas

-Has NO spinous process and NO vertebral body

C2

-Axis

•Bifid Spinous process

•Facets

•Transverse Foramen

•Dens

•Transverse ligament attachment

•Apical ligament attachment

•Alar ligament attachment

C7

Vertebra prominens

Thoracic vertebrae

•12 total vertebrae

•Spinous processes are long and oriented caudally

•Bodies and transverse processes contain articular surfaces for ribs

Thoracic vertebrae articulation

•Costotransverse (costal facet)

•Costovertebral (demi facets 2-10)

Lumbar vertebrae

•5 total

•Bodies are large and heavy

•Sturdy laminae

•Lack costal facets

•Spinous processes are stubby and project posteriorly

Sacrum

•Large, triangular, wedge shaped bone

•Comprised of 5 fused sacral vertebrae

•Sacral promontory

•Sacral hiatus

•Base, Inferior lateral angle (ILA)

Sacrum function

•Provides strength and stability to the pelvis

•Transmits weight of body to the pelvic girdle through sacroiliac (SI) joints

Coccygeal vertebrae

•Remnant tail from embryological development

•4-5 fused vertebrae

•Does not participate in support of body weight

Coccygeal vertebrae provides attachment where?

glutes and coccygeus muscles

Supraspinous ligament

§C7 – sacrum

§Limits FB

Ligamentum nuchae

§Cervical thicker portion of supraspinous ligament

§Triangular median septum between the muscles on each side of the posterior neck

§Limits FB and is an area for muscle attachment

Interspinous ligament

§Between spinous processes

§Limits FB

§Most prominent in the lumbar spine