Lecture 7 (neck) Flashcards
List the bones and cartilages of the neck
1) Inferior aspect of skull and mandible
2) Cervical spine
3) Trachea/larynx
4) Hyoid
5) Clavicle and manubrium
What are the two main layers of fascia in the neck?
1) Superficial fascia
2) Deep cervical facia (which has 3 compartments itself)
What are the 3 compartments of the deep cervical facia?
1) Investing
2) Pretracheal
3) Prevertebral
1) What is the superficial fascia of the neck made of?
2) What does it contain?
1) SQ tissue
2) Contains nerves, vessels, nodes, adipose, and Platysma muscle
1) What does the deep cervical facia allow for?
2) What does it contain, and how is this medically significant?
1) Slippery for movement (swallowing and turning head)
2) Natural cleavage planes; used in surgical contexts and kept in mind as infection spreads
Describe the investing fascia of the deep cervical fascia of the neck; what does it surround and invest in?
1) Surrounds entire neck deep to skin and Superficial fascia
2) “4 corners” “invests” in SCM (sternocleidomastoid) and Trapezius mm.
What innervates the SCM (sternocleidomastoid) and Trapezius mm?
CN11
A) What does the pre-tracheal fascia of the deep cervical fascia of the neck blend into?
B) What are its two parts and what do they enclose?
A) Blends into fibrous pericardium in thorax
B1) Muscular part encloses the infrahyoid mm.
B2) Visceral part encloses the thyroid, trachea, esophagus
1) What does the carotid sheath of the neck enclose?
2) What does the alar fascia enclose? (same layer as carotid sheath)
1) Carotid sheath surrounds carotid arteries
2) Alar fascia and paravertebral fascia fascia form the retropharyngeal space; alar fascia forms the anterior extent of the retropharyngeal space
1) What does the carotid sheath contain besides vessels? How long does it run?
2) What does the carotid sheath blend with?
1) Tubular fascia; cranial base to root of neck
2) All layers of deep fascia
Name 5 groups of structures found within the carotid sheath
1) Common and internal carotid a., carotid sinus n.
2) Sympathetic nerve plexus
3) IJV
4) CNs 9, 10, 11, 12
5) Deep cervical nodes
How is the alar fascia related to the carotid sheath?
Has a bilateral connection to it
Describe the pre-vertebral fascia
It’s tubular fascia for the vertebral column and muscles
1) What does the retropharyngeal space permit?
2) Where is it?
1) Movement of neck visceral relative to the cervical vertebrae during swallowing
2) Between pre-vertebral facia and pre-tracheal (buccopharyngeal) fascia
1) What is the the largest and most clinically important interfascial space in the neck? Why?
2) Where is it?
3) How is the alar fascia related to it?
1) Retropharyngeal space; major pathway for spread of infection in the neck
2) Between pre-vertebral facia and pre-tracheal (buccopharyngeal) fascia
3) Forms the anterior extent of the retropharyngeal space
1) Where is the platysma muscle?
2) What does it do?
1) Covers anterolateral aspect of the neck
2) Muscle of facial expression
1) What muscle divides anterior and lateral regions of neck?
2) What are its 2 inferior origins called?
3) What is the space between these ends called? What is deep to this?
1) SCM (sternocleidomastoid)
2) Clavicular head & sternal head
3) Lesser supraclavicular fossa; deep is the IJV (exam for JVD)
What is a major landmark of the lateral-posterior region of neck?
Trapezius muscle
What are the 3 superficial structures of the Neck?
1) Platysma muscle
2) SCM muscle
3) Trapezius muscle
List the 4 regions of the neck from medial to lateral
1) Anterior cervical
2) SCM region: visibly divides the anterior + lateral regions 3) Lateral cervical
4) Posterior cervical
What nerve is very superficial on the neck?
Spinal accessory nerve (CN11)
The floor of the lateral cervical region is covered by prevertebral fascia and what overlying 4 muscles?
1) Splenius capitus
2) Levator scapulae
3) Middle scalene
4) Posterior scalene
What are the nerves of the lateral cervical region?
1) Spinal accessory n., CN XI
2) Root of the brachial plexus (made of anterior rami of C5-8, T1)
1) Where is the spinal accessory nerve (CN11) in the neck?
2) What innervation does it provide to the neck?
1) Passes deep to the SCM into the lateral cervical region 2) Motor to the trap and SCM
1) What does the root of the brachial plexus contain?
2) Where does it appear?
3) Where does it descend? Into what?
4) What does it provide innervation to?
1) Anterior rami of C5-8, T1
2) Between anterior & middle scalene muscles
3) Between the 1st rib, clavicle and superior boarder of the scapula (cervico-axillary canal) into the axilla
4) Innervation to most of the UE
1) What forms the cervical plexus? What do they form?
2) What are the superficial branches of this plexus?
3) What are the deep branches?
1) Anterior rami C1-4; form series of loops
2) Cutaneous sensory nerves
3) Motor
1) Name a nerve that comes from the cervical plexus that does motor innervation
2) What does it do?
1) Phrenic nerve
2) Traverses entire thoracic cavity to allow diaphragm to contract (somatic motor)
What is the “nerve point of the neck”? What does it provide?
The superficial branches of the cervical plexus; provides cutaneous sensory information
List 4 nerves of the superficial part of the cervical plexus and where they are
1) Lessor occipital n (C2 loop) – posterior auricular
2) Greater auricular n. (C2-3) - parotid gland region
3) Transverse cervical n. (C2-3) to anterior cervical region
4) Supraclavicular n. (C3-4) to lateral shoulder
What is the clinical significance of the nerve point of the neck?
Anesthesia Cervical block for procedures in neck and upper arm; infiltrate along posterior boarder of the SCM jct superior and middle 3rds
Name two deep nerves of the deep branches (passing anteromedially) of the cervical plexus
1) Phrenic
2) Ansi Cervicalis (anterior cervical region) is made of branches of C1-3 [of the plexus]
1) What part of the cervical plexus is the phrenic nerve?
2) What innervation does it provide?
3) Where is the accessory phrenic nerve?
1) C3-4-5
2) Mixed somatic motor, sensory, sympathetic to mediastinum
-Sole motor to diaphragm
3) C-5
anterior cervicalis
Cervicalis (anterior cervical region)
branches from C 1-3
What comes from C1 of the cervical plexus? What does it provide nerves to?
1) A branch of hypoglossal
2) Nerves to the geniohyoid and thyrohyoid mm.
1) What would disruption of phrenic nerve cause?
2) Give an example of this
1) Paralysis of the ipsilateral diaphragm
2) Local anesthesia via phrenic nerve block paralyses ipsilateral diaphragm for thoracic surgery
-Infiltrate around the nerve where it lies on the anterior surface of the anterior scalene muscle.
When is jugular venous distention seen, where, and on which side?
When a patient is in their bed around 30 degrees, their right IJV (between heads of SCM) can be seen distended with visible pulsations when IJV has high pressure.
Why is the EJV (external jugular v) often “full”?
Due to volume overload in HF (heart failure)
1) What may the EJV serve as?
2) What does it look like when pressure is normal?
3) What about when pressure rises (like in HF)?
1) An “internal barometer.”
2) EJV is usually visible superior to the clavicle for only a short distance.
3) The vein is prominent throughout its course along the side of the neck.
Why is the EJV important?
Routine observation for distention of the EJVs during physical examinations may reveal diagnostic signs of heart failure, obstruction of the superior vena cava, enlarged supraclavicular lymph nodes, or increased intrathoracic pressure.
1) What are the two clinically relevant veins in the lateral cervical region?
2) Where are central lines placed?
3) What is at risk of puncture when that’s done?
1) Brachiocephalic and subclavian veins
2) Subclavian vein
3) Pleura and subclavian artery at risk of puncture
Where is the carotid artery in comparison to the IVJ?
Runs medial to IJV
Where is the anterior cervical region?
From SCM’s anterior margin to midline
1) Muscles of the anterior cervical region are made up of what?
2) Where are some attached to?
1) Extrinsic muscles of the pharynx
2) Hyoid bone
What are the two types of muscles that attach to the hyoid bone?
1) Suprahyoid muscles - superior
2) Infrahyoid muscles - inferior
hyoid
1) What do the muscles of the anterior cervical region (aka extrinsic muscles of the pharynx) do?
2) What are they innervated by?
1) Steady or move the hyoid and larynx
2) CNs (9&10) and cervical plexus
What forms the Adam’s apple?
Anterior aspect of thyroid cartilage
1) Where are the suprahyoid muscles?
2) What do they make up?
3) What do they support?
4) What do they do?
1) Superior to hyoid bone connecting the hyoid to head/jaw
2) Floor of the mouth
3) Supports hyoid bone; providing a base from which the tongue functions
4) Elevating hyoid and larynx in relation to swallowing and tone production
1) What innervates the suprahyoid muscles?
2) What specific nerves?
1) Generally cranial nerves
2)
-CN V3 (motor component)
-C-1 via CN 12 to geniohyoid and thyrohyoid muscles.
-CN 7 (other muscles)
1) Where are the infrahyoid muscles?
2) What do they anchor? To where?
3) What are they generally innervated by?
1) Inferior to hyoid bone
2) Anchor hyoid to sternum, clavicle, & scapula, depressing the hyoid and larynx during swallowing & speaking
3) Cervical plexus
1) What does the internal carotid not have branches to?
2) What does it enter? Via what?
3) What does it supply? Using what branches?
4) How does it provide the central retinal artery?
1) No branches in the neck
2) Cranium via carotid canal
3) Main blood supply to brain and orbits; supratrochlear and supraorbital arteries
4) Via ophthalmic artery
External carotids supply what?
MOST structures outside of the brain + meninges
What carotid artery has branches in the neck?
External
1) Where does the superior thyroid artery come from?
2) Where does the inferior thyroid artery come from?
1) First or second branch of external carotid
2) Thyrocervical trunk
What 7 arteries come from external carotid?
1) Superior thyroid
2) Lingual
3) Facial (pulse)
4) Occipital
5) Posterior auricular
6) Maxillary
7) Superficial temporal (pulse)
1) When is an IJV stick done?
2) Which side is better? Why?
3) How is it done?
4) Where is the needle directed?
5) What artery do you need to be careful to avoid?
1) Diagnostic or therapeutic purposes.
2) The right IJV is preferable because it is usually larger and straighter.
3) Palpate the common carotid artery and inserts the needle into the IJV just lateral to it at a 30-degree angle, aiming at the apex of the triangle between the sternal and clavicular heads of the SCM.
4) The needle is then directed inferolateral toward the ipsilateral nipple
5) Carotid artery; just anterior to IVJ
Name 3 structures within the carotid sheath
1) Common carotid artery
2) IJV
3) Vagus n., CN X
What kind of receptor is the carotid body? What does it do?
Chemoreceptor; monitors PO2 in blood
1) What provides visceral afferent innervation to the carotid body?
2) What does low PO2 cause the carotid body to do?
1) CN IX (Glossopharyngeal n.) & CN X (Vagus n.)
2) Increase rate and depth of respiration & HR, BP
1) What does the carotid sinus do?
2) What kind of receptor is it? What stimulates it?
3) What provides its visceral afferent stimulation?
1) Monitors Systemic BP
2) Baroreceptor; increases in BP
3) CNs 9 & 10 (Glossopharyngeal & Vagus)
What part of the head does not have lymph nodes?
The scalp
1) What form the jugular lymphatic trunk?
2) What does the jugular lymphatic trunk anastomose with?
3) What does the thoracic duct drain?
1) Efferent lymph from deep lymphatics
2) Anastomose with thoracic duct on left
3) Everything but right upper quarter (right head and neck, arm, right upper thorax)
1) Where is the brachial plexus?
2) What does it extend to?
3) What is it formed by?
4) What does it provide?
1) Lateral cervical region
2) Extends to axilla
3) Union of anterior rami of C5-T1
4) Sympathetic fibers from middle and inferior cervical ganglia
1) What does CNX arise from?
2) Where does it exit the cranium? With what?
3) Where does it continue in and to?
1) Series of rootlets from medulla (motor nuclei)
2) Via Jugular foramen with Glossopharyngeal (CNIX) and Spinal Accessory n. (CN XI) and IJV.
3) Inferiorly in carotid sheath to the root of the neck
1) What does the vagus nerve supply? What do these structures do?
2) What nerve does it branch off to that’s often injured during neck surgeries? What does this cause?
3) Which side is more often injured?
1) Branches to palate, pharynx and larynx; voice, swallowing (efferent GAG reflex)
2) Recurrent laryngeal nerve; dysphonia or aphonia
3) Left recurrent laryngeal, because it’s longer
1) What do the presynaptic cells of the sympathetic ganglia do?
2) How do motor nerves reach this area?
3) Where are the postsynaptic cells? What do they surround?
1) Presynaptic cells intermediolateral horn spinal cord thoracic lumbar
2) Via anterior or efferent spinal roots
3) In paravertebral ganglia or prevertebral ganglia, in plexus surrounding origins of main branches abdominal aorta
What structure is only parasympathetic?
Ciliary body (is constricted by parasympathetic for accommodation)
*probably on quiz
What innervates the iris?
Sympathetic
*probably on quiz
Name a structure that is only sympathetically innervated
Smooth muscle of arteries
What causes Horner’s syndrome?
Lesion to sympathetic trunk in the neck
1) What are 4 affects caused by Horner’s syndrome?
2) What causes each?
3) What type of lesion causes Horner’s?
4) Why does it cause anhidrosis?
1) Miosis: Pupillary constriction; unopposed parasympathetic pupillary constrictor
2) Ptosis: loss of sympathetic innervation to levator palpebrae superioris smooth muscle (superior tarsal m.)
3) Enophthalmos
4) Anhidrosis on face and neck: loss of sympathetic “tone” to vessels and innervation to the sweat glands
-Because it’s caused by a lesion to sympathetic trunk in neck
What does the CN11 (spinal accessory nerve) provide sensory and motor innervation to?
1) Somatic motor to SCM (sternocleidomastoid) and Trapezius mm.
2) Sensory to same area
If you can’t shrug your shoulders, what nerve could be malfunctioning?
CN11 (spinal accessory)
1) Where is CN11 (spinal accessory), superficial or deep?
2) What is the clinical relevance of this?
3) Give examples.
1) Superficial location
2) Easily injured during surgeries
3) CEA, lymph node Bx, cannulation of internal jugular vein
What does the thyroid wrap around? (2 things)
Trachea anteriorly, esophagus posteriorly
What is a Cricothyrotomy? When do you do it and how long does it last?
1) The placement of an emergency airway in the cricothyroid membrane
2) Emergency procedure; temporary
What are the two types of laryngeal muscles and what are their primary jobs?
1) Extrinsic: Move the entire larynx
2) Intrinsic: Move laryngeal parts for voice
Name three extrinsic laryngeal muscles and what they do
1) Infrahyoid muscles depress hyoid and larynx
2) Suprahyoid muscles and stylopharyngeus muscles elevate hyoid and larynx
1) What do the intrinsic laryngeal muscles do?
2) What nerve(s) supply them?
1) Move laryngeal parts for voice
2) All but one (cricothyroid m. supplied by external laryngeal n.) are supplied by recurrent laryngeal nerve (br. of CN X, Vagus n.)
What muscles are responsible for Voice change and abnormal efferent GAG reflex? What do they give clues to?
Intrinsic laryngeal muscles; vagus n. function
What is the afferent pathway for the cough reflex to the brain? (3 steps)
1) Internal laryngeal n.
2) Via superior laryngeal n.
3) Via Vagus n. to medulla then on to cortex ( no identified cough center)
What is the efferent pathway for the cough reflex from the brain? (3 steps)
1) Vagus n.
2) To superior laryngeal n. and nerves
3) To glottis and respiratory/expiratory muscles
1) What is a tracheotomy?
2) Is it temporary or permanent?
1) An O.R. procedure for airway placement
2) Permanent
What are the 3 parts of the pharynx and their locations?
1) Nasopharynx
2) Oropharynx
3) Laryngopharynx
What two things are found in the nasopharynx?
Pharyngeal tonsils (adenoids)
Eustachian tube
1) What is the oropharynx responsible for?
2) What can you find within it?
1) Swallowing function
2) Tonsils (palatine)
What are the two layers of pharyngeal muscles? What do they do?
1) External layer: constricts wall during swallowing
2) Internal layer: elevate pharynx and larynx during swallowing and speaking
What provides the pharyngeal muscles with motor innervation? What is it responsible for?
CN X, Vagus n. (active gag)
1) What does the cervical plexus provide the most innervation to?
2) What nerves are involved with the cervical plexus?
1) Motor to infrahyoid
2) Mostly spinal, but some hypoglossal nerve involvement
