Neck 4-6 Flashcards
1
Q
Cervical Nerves of Neck
A
- cervical plexus: anterior rami of C1-C4
- Posterior rami: C2–C5 -> innervate intrinsic (deep) back muscles + skin (dermatomes)
- greater occipital nerve – back of scalp
2
Q
Cranial Nerves of neck
A
- CN V (Trigeminal): mylohyoid, anterior digastric
- CN VII (Facial): facial muscles, platysma, posterior digastric, stylohyoid
- CN IX (Glossopharyngeal): carotid body + sinus
- CN X (Vagus): branches supply larynx + pharynx
- CN XII (Hypoglossal): passes thru/over carotid -> oral cavity + tongue
3
Q
Damage in Post/Ant Root/Rami
A
- Post root - Lose sensory in body wall/skin (dermatomes) = numbness
- Ant root - Lose motor = muscles weakness
- Post ramus (GSA + GSE) - Lose sensory + motor – muscle weakness, dermatome affected
- Ant ramus - Lose sensory + motor in the antero-lateral parts of trunk and limbs – muscles weak, loss of sensation
4
Q
Spinal Nerves
A
- ant rami - has GSE (motor fibers to skeletal muscle) in all 31 levels
- GVE = T1-L2
- ant + post rami mixed, contain all - GSA, GSE, GVA, GVE
- gray rami = postgang symp, unmyelinated neurons
5
Q
Loops/interconnections btwn C1-C2, C2-C3, etc. of cervical plexus
A
- C1 axons go down, join axons from C2
- overlap – any of nerves has more than 1 spinal level
- effects of damage (lesion) at C1 minimized
6
Q
Sensory nerves of cervical plexus
A
- 4 cutaneous nerves = lesser occipital, greater auricular, transverse cervical, supraclavicular nerve -> innervate skin
- Proprioceptive axons = subtrapezial plexus (follows spinal accesory to traps) -> tell brain position/status of trapezius
7
Q
Motor Nerves of cervical plexus
A
- innervate skeletal msucles
- derived from ansa cervicalis - has axons from C1-3 (innervates strap muscles), hitchhikes with CN XII
- C1 -> thyrohyoid
- phrenic nerve (C3-C5) - ant scalene muscle
8
Q
Nerve Point
A
- on post SCM border, middle 1/3
- 4 cutaneous nerves (C1-4 of cervical plexus) go from behind muscle to their locations
- Transverse cervical goes thru platysma (post to ant) but doesn’t innervate it -> facial nerve
- numb all nerves w/one shot of anesthesia
9
Q
Scalene Triangle + Brachial Plexus
A
- TCA = front to back; TCN = back to front
- Phrenic nerve + accessory phrenic nerve = on top of ant. Scalene.
- brachial plexus + subclavian artery go thru scalene triangle
10
Q
Superior laryngeal nerve
A
- in neck above digastric muscles
- divides into ext + int laryngeal (one inside larynx, one outside)
- both branches + recurrent laryngeal innervate larynx
- int laryngeal also innervates root of tongue, epiglottis
11
Q
Axon Types of CN X (Vagus)
A
- pregangs in brainstem, postgangs in organ wall (larynx, esophagus, trachea - very short)
- SVE = motor [skeletal muscle]
- GVE = parasympathetic
- SVA = taste
- GVA = visceral afferent - return to brain, monitor viscera + mucosa
12
Q
Recurrent/Inferior Laryngeal
A
- goes under subclavian art (on right) or under aortic branch (on left) and gets picked back up
- At trachea, have same relationship
13
Q
3 Neurovascular Pairs of Larynx
A
- Superior Laryngeal artery + Internal branch of superior laryngeal nerve
- Superior thyroid artery + external branch of superior laryngeal nerve
- Inferior laryngeal artery + Recurrent Laryngeal nerve
14
Q
Lesions of Vagus Nerve
A
brain stem lesion (hemorrhage, neoplasm) skull base tumors carotid/thyroid surgery aortic aneurysm bronchial carcinoma
15
Q
Cervical Symp Chain Patterns
A
- T1- T4 IML -> white ramus -> symp chain -> go up chain -> postgang axons leave chain -> airway (esophagus, pharynx) + head (lacrimal glands, etc.)
- postgangs also leave via gray rami at every spinal level, go to ant + post rami -> skin, etc.
16
Q
Parasymp vs Symp
A
- parasymp from CN X (Vagus), specific -> stay in body cavities, don’t innervate skin
- symp go everywhere -> all cutaneous sensory nerves, glands
17
Q
Cervical Symp Chain
A
- symp chain from skull base to coccyx, btwn carotid sheath + prevertebral fascia
- thorax symp ganglion at every thorax level - beads on string, but cervical chain pregangs from T1-T4
- embryologically same in neck -> 3-4 ganglia in neck for 8 nerves
18
Q
Cervical Symp Ganglia
A
- Superior cervical ganglia (mega ganglia) - C1-C4
- middle ganglia - C5-C6
- Inferior Cervical - C7-C8
- Cervicothoracic (stellate) - C8-T1 (spinal nerve lvls, not spinal cord
- sometimes vertebral gang on vertebral art
19
Q
Carotid Nerves
A
- internal + external carotid nerves follow BVs to head for symp innervation (hitchhiking, facial nerve does same)
20
Q
Laryngopharyngeal branches
A
come off of ganglia
21
Q
Cervical Symp Cardiac Nerves
A
- down neck -> chest cavity -> heart (multiple nerves)
- due to dvlpt -> heart started in front of head, w/growth heart descends w/nerves
22
Q
Lesion of Cervical Symp Trunk
A
- lose control to sweat glands – skin dries
- lose vascular tone – vessels dilated = flushing (Red) in skin on neck and face
- affects on eyelid + pupils
- Horner’s syndrome
23
Q
Lesser Occipital Nerve
A
GSA (sensory to skin)
GVE (motor to sweat glands, blood vessels)
GVA
24
Q
Inferior root of ansa cervicalis
A
Motor – innervating skeletal muscle (omohyoid muscle)
GSE + GSA - muscle
GVE + GVA – blood vessels
25
Neck Viscer
- Pharynx (behind nasal + oral cavity) - nasopharynx, oropharynx, laryngopharynx (guards entrance to esophagus + pharynx)
- esophagus
- larynx
- trachea
- thyroid + parathyroid glands
26
Esophagus cervical portion
- upper 1/3 = skeletal muscle, middle 1/3 = mixed, lower 1/3 = smooth muscle
- innervated by vagus nerve
27
Laryngeal Cartilages
- Hyoid bone – anchors, support laryngeal structures
- Adam’s apple – thyroid cartilage, C shaped, incomplete in back
- below = crycoid cartilage = complete ring – thin in front, tall in back, below it are C shaped rings
- Arytenoid cartilage – pyramidal shaped, processes extending forward and back for muscle attachments
- Epiglottis
28
Laryngeal Cartilages Articulations
- articulations btwn cartilage -> form synovial joints w/each other
- Thyroid cartilage articulates w/facet on cricoid cartilage, allows thyroid cartilage to rock back and forth.
- Arytenoid cartilage also articulate w/cricoid cartilage – allows them to swivel around + adduct (pull together)
29
Laryngeal Membranes - thyrohyoid membrane
- dense fibroCT that connects hyoid bone to thyroid cartilage -> whenever hyoid bone moves, rest of larynx does also
- has opening/aperature transmitting travelling pair btwn sup laryngeal art + int laryngeal nerve
- has diff thickenings, like in front
30
Laryngopharynx
- Larynginelal inlet – spoon shaped part of epiglottis, rest is aryepiglottic fold -> connects arytenoid cartilages up to epiglottic cartilage.
- Vestibule (space inside)
- On either side = piriform recess.
- in swallow, food goes over piriform recess on sides, then to esophagus (things can get stuck there, need to be pulled out - fishbone)
31
Laryngeal Spaces + Folds
- vestibule (synonymous w/laryngeal introitus), vestibular fold on top
- vocal fold on bottom (vocal cord)
- btwn both folds = laryngeal ventricle
- Rima vestibuli + rima glottis = space btwn folds from left to right
32
Laryngeal membranes - quadrangular mem + cricothyroid lig
- Folds = mucosa + CT bands
- Quadrangular membrane = CT band btwn epiglottis, end inferiorly as vestibular ligament, gives support
Cricothyroid ligament = ends superiorly as vocal lig/cord (skeleton of vocal fold)
33
Infections of Laryngeal Saccule (Ventricle)
- infections in laryngeal ventricle spread along sup recess. - hole in thyroid mem -> infection moves out to neck, deep to pretracheal fascia (spread in tube of pretracheal and buccopharyngeal fascia)
- Laryngocoele = inflated, enlarged saccule
34
Larynx attachment to skeleton
- Stylohyoid (muscle + lig), digastric
- Geniohyoid and mylohyoid
- Infrahyoid muscles
35
Cricothyroid Muscle
- on outside, innervated by external laryngeal nerve (all others innervated by recurrent laryngeal nerve).
- rocks thyroid cartilage fwd, tightens vocal liga and vocal cord (voice goes higher).
36
Thyroarytenoid
- attaches to thyroid cartilage, goes back to arytenoid.
- Pulls arytenoid + thyroid closer together
- Creates less tension in vocal ligs = Voice goes deep
37
Vocalis Muscle
smaller, precise changes on vocal ligs
38
Lateral Cricoarytenoid + Posterior Cricoarytenoid
- Antagonistic muscles, but both go from cricoid cartilage to arytenoid cartilage.
- Change width/size of rima glottis.
- Posterior cricoarytenoid opens rima glottis by pulling muscles to midline
- Lateral - pulls muscles forwards, closes rima glottis
- Both nnervated by recurrent lar. n.
39
Transverse Arytenoid
Oblique Arytenoid
Aryepiglotticus
- all assist in closing rima glottis
- Transverse arytenoid pulls arytenoids together, closing rima glottis more.
- Aryepiglotticus – transverse + more oblique, doing same thing – pulling vocal folds together “trap door” -> Helps to close.
40
Larynx Innvervation
- internal superior laryngeal nerve -> Iarynx glands (mucosa)
- external superior laryngeal nerve -> mainly motor
- Recurrent laryngeal nerve – muscles/mucosa, epithelium
- vocal folds = dividing line btwn internal + recurrent
41
Cough reflex
- If dental loop above fold -> internal laryngeal nerve
| - if below/tumor on vocal cord -> afferent response from recurrent laryngeal nerve
42
Larynx Vasculature
- Superior laryngeal art + branches from inferior thyroid
- Supply from subclavian + superior thyroid art
- Return blood in venous system thru thyroid veins (superior thyroid vein, sup laryngeal vein, middle thyroid vein)
43
Lymph drain of larynx
- Above vocal cords - Supraglottic – upper deep cervical nodes (jugulodigastric – C2)
- Below vocal cords - Infraglottic – pretracheal, lower deep cervical (Juguloomohyoid – C4)
- Laryngeal tumor – dictates what nodes to affect – cord + below = deeper nodes; higher = superior deep nodes
44
Thyroid gland
- doesnt completely surround larynx/trachea (C-shape from above)
- has isthmus = narrow band in front w/R+L lobes
- 10-20% have pyramidal lobe (in middle)
- endocrine gland - secretes hormones into blood -> dense vasculature (significant arts + veins)
45
Parathryoid gland
- back of lateral lobes of thyroid glands, usually 4, but range from 2-7
- position variable -> not always in thyroid gland, stuck in fascia outside gland)
- position imp for determining tumor spread
* **variable in number + location
46
Vasculature of thyroid + PTH
- 10% of ppl have thyroid ima artery – extra vessel in midline, comes from below from thorax
- crosses superior aperture, goes to gland.
- in tracheostomy, if you cut this, will bleed a lot b/c its a branch off aorta (paramital wont be supplied)
- Venous drainage = superior/middle/inferior thyroid veins -> 1 or 2 vessels that go to either branch of cephalic, 5-6 vessels draining.
- Very vascularized**
47
IV disc between CIII & CIV
- same horizontal plane as bifurcation of common carotid art into internal/external carotid arts
- approx at upper margin of thyroid cartilage)
48
Vertebral level VCI
- transition from pharynx to esophagus and larynx to trachea
- marks superior ends of esophagus + trachea
- approx. at level of inferior margin of cricoid cartilage.
49
Anterior triangles
- base each triangle = inf margin of mandible
- anterior margin =neck midline
- posterior margin = anterior border of SCM
- apex points inferiorly, at suprasternal notch
- triangles assoc w/airway, digestive tract, nerves, vessels btwn thorax + head – also assoc. w/thyroid + PTH
50
Posterior triangles
- Base = middle 1/3 of clavicle
- Medial margin = posterior border of SCM
- Lateral margin = anterior border of traps
- Apex points superiorly, immediately posteroinferior to MP
- Posterior triangles assoc w/nerves + vessels that pass in/out of upper limbs.
