Neck I and II Surface anatomy, fascias and spaces

Question 1

where can you palpate the body and greater horn of the hyoid

Answer 1

anteriorly immediatley superior to the prominence of the thyroid cartilage (opposite the third cervical vertebra)

laterally its greater horn is palpable

Question 2

where is the thyroid cartilage located

Answer 2

opposite the 4th and 5th CV

superior thyroid notch and laryngeal prominence area easily palpable anteriorly

Question 3

where is the cricoid cartilage located

Answer 3

anterior to the 6th cervical vertebra

this “signet” ring shaped cartilage is palpable directly inferior to the thyroid cartilage

Question 4

what are the tracheal rings

Answer 4

d shaped cartilages

their open areas face posteriorly

Question 5

where is the thyroid isthmus palpable

Answer 5

across the level of the 2nd, 3rd and 4th tracheal rings

Question 6

in which fascial layer is the platysma located

Answer 6

within the superficial fascia layer

Question 7

what are the attachments of the platysma

Answer 7

Origin–> superficial fascia covering the pectoralis major and deltoid

insertion–> inferior margin of mandible, skin and subcutaneous tissues of the lower portion of the face and corner of the mouth

Question 8

what is the action of the platysmus

Answer 8

draws corner of mouth downward, depresses mandible, elevates skin of chest

Question 9

what is the innervation of the platysmus

Answer 9

cervical branch of facial nerve (CNVII) - derivative of 2nd arch

Question 10

what are the fascial layers of the cervical region

Answer 10

superficial 
deep: 
investing 1
infrahyoid 2 (superficial, deep)
cervical visceral (pre-tracheal 3, buccopharyngeal 4)  
Prevertebral 5 --> alar 6 
specializations of pre vertebral (sibson's and axillary) 
carotid sheath

Question 11

what are the superior and posterior attachments of the investing fascia

Answer 11

superior –> external occiptal protuberance, superior nuchal line, mastoid porcess and inferior margin of the mandible

posterior –> external occipital protuberence, spinous processes of CV1- CV7 via the nuchal ligament

Question 12

what is the inferior attachment of the investing fascia

what is the suprasternal space

Answer 12

line connecting inferior attachment–> spinous process of CV7, spine of scapula, acromion, clavicle and manubrium,

blends with inferior attachments of SCM and trapezius and attaches to the invervening middle on-third of the clavicle

where the laminae from both surfaces of the SCM fail to fuse anteriorly and inferiorly they form a small suprasternal space which is normally filled with fat and contains a vein which communicates with the inferior portion of the anterior jugular veins

Question 13

what does the investing facia surround

Answer 13

SCM and trapezius

also forms a CT capsule for the submandibular gland

Question 14

where does the infrahyoid fascia begin (2nd layer of deep fascia) and what are the two layers

Answer 14

beginning at the hyoid bone and thyroid cartilage , this facial forms two definite layers which invest the infrahyoid muscles

superficial and deep layers

Question 15

what does the superficial layer of infrahyoid fascia surround
where does it attach inferiorly

what does it fuse with laterally and what other structure does it form

Answer 15

invests sternohyoid and omohyoid

inferiorly attaches to the posterior surface of the manubrium

latearlly it fuses with the periosteum of the clavicle and first rib –> forms a sling for the intermeidate tendon of the omohyoid muscle

Question 16

what does the deep infrahyoid fascia layer invest and where does it attach inferiorly

Answer 16

invests sternothyroid and thyrohyoid muscles

attaches inferiorly to the posterior surface of the manubrium

Question 17

inferiorly where do the two layers of infrahyoid fascia fuse and laterally where do they fuse

Answer 17

inferirly –> adventitia of the brachiocephalic veins and fibrous pericardium via the sternopericardial ligament

laterally with the carotid sheath

Question 18

what are the two layers of cervical visceral fascia

Answer 18

pre-tracheal (3)

buccopharyngeal (4th layer) b

Question 19

what are the superoir and anterior attachments of prevertebral fascia

Answer 19

superior – base of skull

anterior - covers the pre-vertebral musculature and extends inferiorly into the posteiror mediastinum

Question 20

what are the attachments of alar fascia

Answer 20

anteriorly the pre-vertebral fascai bifurcates to form the alar fascia

attaches midline of the buccopharyngeal fascia
bilaterally blends with the carotid sheath and inferiorly blends with the adventitia of the esophagus in the superior mediastinum between CV7 and TV3

Question 21

what are the inferior and posterior attachments of pre-vertebral fascia

Answer 21

lateral-> attaches to the cervical transverse processes and forms the floor of the posterior cervical triangle where it covers the scaliness, levator scapulae, splenius, and semispinalis muscles

posterior–> from the nuchal lines and mastoid processes to cervical spinous processes
inferiorly it fuses with the thoracolumbar fascia of the deep back

Question 22

what are the two specializatons of prevertebral fascai

Answer 22

sibson’s fascia (suprapleural membrane)
underside of the scalene muscle

axillary sheath–> reflected laterally along the subclavian and axillary vessels and brachial plexus

Question 23

what is the carotid sheath

what does it surround

where does it attach

Answer 23

neurovascular component of deep fascia, surrounds the:
common and internal carotid arteries
internal jugular vein
vagus n.

attaches superiorly to base of skull
inferiorly fuse with the adventitias of the great vessels and fibrous pericardium

Question 24

what attaches to the carotid sheath

Answer 24

all deep fascias of the neck blend laterally and attach to this

Question 25

what is space 1

Answer 25

suprasternal space

Question 26

what is space 2

Answer 26

pre-tracheal or visceral space located between the deepest layer of infrahyoid fascia and the pre-tracheal fascia extends from the level of the attachment of the infrahyoid muscles to the thyroid cartilage above to the attachment of the pericardium to the roots of the major vessels in the superior mediastiunum below

Question 27

what is space 3

Answer 27

retropharyngeal space or retrovesical a smaller more anterior space between the buccopharyngeal and alar fascias extends from base of skull above to a point approximately opposite CV7-TV3 where the alar fascia blends with the esophagus in the neck or as far inferior as the superior mediastinum

Question 28

what is space 4

Answer 28

Danger space retropharyngeal space a larger more posterior space located b/w the prevertebral and alar/buccopharyngeal fascias extending from the base of the skull to the DIAPHRAGM b/w the vertebral column and esophagus i

Question 29

infection in the pretracheal space

Answer 29

can dissect into the superior mediastinum leading to inflammation of the brachiocephalic veins, aorta, and pericardium

Question 30

infection in the danger space and what does this have to do with chronic tonsillitis

Answer 30

can lead to retropharygneal abscess which can lead to dysphagia and dysarthria and can dissect into the posterior aspect of the superior and posterior mediastinum chronic tonsillitis can lead to mediastinal abscess thereby leading to inflammation of the esophagus as far distally as the diaphragm

Question 31

what are the anterior and posterior general boundaries of the neck superior and inferior ?

Answer 31

anterior - line from symphysis menti to the sternal notch posterior trapezius (anterior) border superior- line that connects the superior nuchal line, mastoid process and inferior margin of the mandible to the symphysis menti inferior - superior margin of the clavicle, sternoclavicular joint and sternal notch

Question 32

what are the attachments of the sternocleidomastoid

Answer 32

Origin- sternal head- manubrium clavicular head- proximal 1/3 of clavicle inseration - mastoid process and superior nuchal line (lateral half)

Question 33

what is the action of the SCM

Answer 33

unilaterally acting- rotates head toward side opposite while elevating chin bilaterally acting - flexes head, limited extension of the atlanto-occiptial joint

Question 34

what is the innervation of the SCM

Answer 34

``` Spinal accessory (CN XI) cervical spinal nerves C2 and C3 ```

Question 35

torticollis (wry neck)

Answer 35

congenital or acquired results in shortening of the SCM which places the patients head in a positition side bent to the same side and rotated to the side opposite the affected muscle

Question 36

what are the boundaries of the posterior triangle

Answer 36

``` posterior - trapezius anterior- SCM inferior - clavicle subdivided by the passage of the inferior belly of the omohyoid muscle into: occipitlal triangle omoclavicular triangle ```

Question 37

occipital triangle

Answer 37

larger, more superior triangle bounded by the trapezius, SCM and inferior belly of omohyoid

Question 38

omoclavicular triagnle (subclavian or supraclavicular triangle)

Answer 38

small, more inferior | bounded by inferior belly of omohyoid, clavicle and SCM

Question 39

what are the boundaries of the anterior triangle

Answer 39

bound by SCM posteriorly angle of the mantle superiorly and an imaginary line mid-sagitally subdivided by the passage of the digastric and omohyoid muscles to form: digastric triangle and submental triangle, carotid triangle, muscular triangle

Question 40

digastric triangle

Answer 40

bounded superiorly by the inferior margin of the mandible | inferiorly by the two bellies of the digastric muscle

Question 41

submental triangle

Answer 41

bounded laterally by the two opposing anterior bellies of the digastric muscles and the hyoid bone

Question 42

Carotid triangle

Answer 42

bounded superiorly by the posterior belly of the digastric | anteriorly by the superior belly of the omohyoid and posteriorly by the SCM

Question 43

muscular triangle

Answer 43

bounded posterior superiorly by the usperior belly of the omohyoid posterior inferiorly by the SCM anteriorly by the median line of the neck to the hyoid bone

Question 44

what veins form the external jugular vein

Answer 44

union of posterior division of the retromandibular and the posterior auricular veins at the angle of the mandible

Question 45

what is the course of the External jugular vein

Answer 45

descends from its formation superficial to the SCM | pierces the investing fascia to gain the root of the neck behind the claivcle where it terminates in the subclavian vein

Question 46

what are the tributaries of the external jugular vein (4)

Answer 46

posterior external jugular transverse cervical suprascapular anterior jugular

Question 47

what does increased filling of the external jugular vein reveal

Answer 47

heart failure SVC obstruction enlarged supraclavicular lymph nodes or increased intrathoracic pressure

Question 48

what causes air embolism

Answer 48

laceration of external jugular vein along the poseterior border of the SCM can lead to this due to negative intrathoracic pressure which sucks air into the open vein see notes

Question 49

what is the formation of the anterior jugular veins

Answer 49

small veins in the submental and submandibular regions coalesce at the level of the hyoid bone to form the anterior jugular vein

Question 50

what is the course of the anterior jugular vein

Answer 50

from hyoid bone to medial inferior most extent of the anterior triangle pierces investing fascia and continues inferiorly within the suprasternal space where it communicates with its opposite fellow via the jugulovenous arch!!! then it turns laterally coursing deep to the SCM to join the external jugular vein

Question 51

what forms the common facial vein

Answer 51

anterior division of the retromandibular vein and facial vein the common facial vein then pierce the carotid sheath and joins the internal jugular

Question 52

what forms the communicating vein

Answer 52

the union of the retromandibular and facial veins the communicating vein then follows the anterior border of the SCM to communicate with the anterior jugular system

Question 53

where do a portion of the superficial cervical lymph nodes lie in the neck

Answer 53

along the path of the external jugular vein

Question 54

what are the dorsal rami that are the cutaneous contribution to the neck

Answer 54

C1 spinal nerve-> has no dorsaal root in 50% of individuals C2 greater occipital n. C3-C6

Question 55

what are the ventral rami (cutaneous nerves) that are involved in the innervation of the neck

Answer 55

C2-C4 in general Lesser occipital C2, C3 Greater auricular C2, C3 Transverse cervical C2, C3 Supraclavicular C3, C4 the above nerves emerge from beneath the posterior border of the SCM in the posterior triangle

Question 56

lesser occiptial

Answer 56

C2 C3 posterior border of SCM (ascends) innervates medial surface of the ear as well as the skin behind the ear

Question 57

greater auricular nerve

Answer 57

C2, C3 ascends towards the angle of the mandible paralelleing the external jugular vein provides branches to mastoid process lower portion of both surfaces of the ear and the inferior portion of the angle of the mandible and parotid region

Question 58

transverse cervical nerve

Answer 58

C2, C3 crosses lateral surface of SCM inferior to the great auricular nerve and deep to external jugular vein travels deep to the platysma where it divides into two branches (superior and inferior) which pierce the platysma to innervate the skin and subcutaneous tissue of the anterior triangle from the mandible to the sternum

Question 59

supraclavicular nerve and its branche

Answer 59

C3 C4 medial supraclavicular -base of neck, upper sternum, and sternoclavicular joint intermediate- crosses the clavicle to innervate skin over pectoralis major as far inferior as third rib lateral -crosses the clavicle in the area of the acromioclavicular joint and provides cutaneous innervation to the prominence of the shoulder

Question 60

cervical nerve block what are the consequences (b/c of other nerves)

Answer 60

includes the supraclavicular, lesser occ, greater auricular, transverse cervical anesthetized during the normal course of surgical approaches to superficial or deeper areas of the neck however, the phrenic nerve shares spinal cord levels of innervation (C3-C4) with the spinal cord levels of origin of the cervical plexus and therefore the ipsilateral hemidiaphragm will also be paralyzed don't use this on patients with significant respiratory or cardiac disease

Question 61

cervical plexus cord levels

Answer 61

C1=C4

Question 62

what are the 4 major superficial cervical lymph nodes where do they drain

Answer 62

submental submandibular external jugular anterior jugular drain to deep cervical lymph nodes ``` receive lymph from: lower portion of ear and parotid region facial region portions of the oral cavity submandibular and sublingual salivary skin of the anterior neck and muscles of the infrahyoid region ```