Neck/Head/Thorax/Spine/Abdomen Flashcards
Sternocleidomastoid
ACTION
Bilateral: - flex head against resistance -neck flexion -extension at the A-O joint (posterior fibers only) -accessory muscle of respiration
Unilateral: -ipsilateral sidebend with contralateral rotation of the face
PROXIMAL: Sternal head: manubriu, Clavicular head: upper medial 1/3 clavicle DISTAL: to lateral surface of mastoid process & lateral 1/2 superior nuchal line
INNERVATION: CN XI (motor); C2, C3 ventral rami (sensory)
Anterior, Middle, Posterior Scalenes
ACTION
- Ipsilateral sidebending of cervical vertebra
- Reverse action: elevate first and second rib during inspiration
PROXIMAL
Anterior: transverse process CV3-CV6
Middle: post tubercles transverse process CV5-CV7
Posterior: post tubercles transverse process CV5-CV7
DISTAL
Anterior: 1st rib
Middle: sup surface 1st rib
Posterior: 2nd rib
INNERVATION
Anterior : C4-C6 ventral rami
Middle : ventral rami C3-C8
Posterior : ventral rami C7, C8
Levator Scapulae
ACTION
- Elevates scapula
- downward rotation of scapula with pec minor ms
PROXIMAL
-Posterior tubercles transverse processes of from CV1-CV4
DISTAL
-To medial border of scapula at & above the spine
INNERVATION
-C3-4 ventral rami; C5 ventral rami from dorsal scapular n.
Platysma
ACTION: depresses mandible and tenses skin of inferior face and neck
-Superficial to investing layer of fascia
INNERVATION: CN VII
Investing layer of fascia
Surrounds:
- trapezius
- sternocleidomastoid
- acts as roof to anterior triangle of neck
Pretracheal Fascia
Surrounds:
- thyroid gland
- infrahyoid (aka strap) muscles
- trachea
- esophagus (located deep to the trachea)
Prevertebral Fascia
Surrounds:
Prevertebral muscles, longus colli, longus capitus, Scaleni Musculature, Anterior Scalene, Middle Scalene, Posterior Scalene, Levator scapulae, Phrenic nerve, Deep muscles of the back
*Forms the floor of the posterior triangle
AKA: Fascial Carpet/ Floor
*prolonged laterally by forming the axillary sheath which invests the brachial plexus & vessels
Carotid Sheath
Surrounds:
- common carotid & int carotid artery
- internal jugular vein
- vagus nerve (CN X)
- sometimes ansa cervicalis (part of cervical plexus innervating strap muscles)
–> At times may lie superficial to carotid sheath
Anterior Triangle Borders
- roof- investing fascia & platysma
- superior- inferior border of the mandible
- anterior- median line of the neck
- posterior- anterior border of SCM
- Floor-prevertebral fascia
Anterior Triangle Contents
- muscular triangle: infrahyoid muscles, thyroid & parathyroid glands
- carotid triangle:common carotid a., internal jugular v., portions of last 3 cranial nerves
- digastric triangle: submandibular gland, facial artery, internal carotid a., internal jugular v., CN IX, CN X
Strap Muscles
Innervated by: ansa cervicalis of cervical plexus
- Sternohyoid
- Sternothyroid
- Thyrohyoid
- Omohyoid
Posterior Triangle Borders
- roof- fascia & platysma
- anterior- posterior border of SCM
- posterior- anterior border of trapezius muscle
- inferior- superficial aspect middle 1/3 of clavicle
- floor- prevertebral fascia
Posterior Triangle Contents
- transverse cervical a.
- CN XI
- upper trunk of brachial plexus
- subclavian a.
- dorsal scapular n.
- long thoracic n.
- n. to subclavius
- suprascapular a. & n.
Branches off of the subclavian A.
- Vertebral
- Internal thoracic
- Thyrocervical trunk which gives rise to 3 arteries: inferior thyroid, suprascapular, transverse cervical
- Costocervical trunk
- Dorsal scapular
Cervical Plexus
- formed by branches of ventral rami C1-4
- Supplies:
Nuchal (neck) muscles
diaphragm muscle
infrahyoid (strap) musculature
skin of head/neck/chest
-superficial branches (sensory only):
lesser occipital n. - C2
great auricular n. - C2,3
transverse cervical n. - C2,3
supraclavicular n. - C3,4
-Deep branches include:
Motor to prevertebral ms. - ventral rami C1-4
Motor to levator scapula and ant, middle, post scaleni
Motor to infrahyoid muscles via ansa cervicalis – ventral rami C1-3
Motor & sensory to diaphragm via the phrenic n. - C3-5 ventral rami
Sensory to SCM & trapezius- ventral rami C2,3 (NOT MOTOR, ARE SENSORY) (pain & proprioception)
Ansa Cervicalis
- that supplies the infrahyoid muscles (strap ms.)
- C1-3 ventral rami
- consists of two loops (aka roots)
- innervates: sternohyoid, sternothyroid, omohyoid, thyrohyoid
- innervation thyrohyoid: C1 ventral ramus however rides along with the hypoglossal nerve
Infrahyoid muscles
aka strap muscles
- anchor hyoid bone to sternum, clavicle & scapula
- action-depress hyoid bone & floor of mouth; elevate or depress larynx
- innervated by ansa cervicalis
- {thyrohyoid specifically C1 via CN XII}
Suprahyoid musucles
- digastric
- geniohyoid
- stylohyoid
- mylohyoid
Digastric
ACTION: depress mandible; elevates hyoid during swallowing
ATTACHMENT: Anterior and posterior bellies, from the digastric fossa of the mandible and the mastoid notch of the temporal bone to the intermediate tendon to body and greater horn of hyoid bone
INNERVATION: CN V/anterior belly,CN VII/posterior belly
**suprahyoid ms**
Geniohyoid
ACTION: depress mandible; elevates hyoid
ATTACHMENT: from the inferior mental spine of the mandible to the body of the hyoid
INNERVATION: C1 via CN XII
**suprahyoid ms**
Stylohyoid
ACTION: draws hyoid posteriorly & elevates it
ATTACHMENT: superior to post belly digastric, from the styloid process of the temporal bone to the body of they hyoid, superior!!!
INNERVATION: CN VII
**suprahyoid ms**
Mylohyoid
ACTION: elevates hyoid and floor of mouth
ATTACHMENT: mylohyoid line of the mandible and the mylohyoid raphe on the body of the hyoid one. , makes up floor of mouth
INNERVATION: CN V3 = mandibular br. of trigeminal n.
**suprahyoid ms*
External Carotid Artery Branches
- superior thyroid a.
- ascending pharyngeal a.
- lingual a.
- facial a.
- occipital a.
- posterior auricular a.
- superficial temporal a.
- maxillary (gives rise to meningeal a.)
Cranial Nerve VII (Facial Nerve)
PATH: cellbodies originate in pons and medulla–>through internal acoustic meatus and facial canal–> exits stylomastoid foramen
RESPONSIBILITIES:
- Motor supply to the muscles of facial expression
- (Bell’s Palsy-paralysis of muscles of facial expression; no apparent etiology/idiopathic; suspect edema 2’ infection)
- Motor: stylohyoid and posterior belly of digastric ms.
- Parasympathetic innervation (motor): secretion of tears (lacrimal gland) and saliva (sublingual and submandibular salivary glands)
- Special sensory: taste to anterior 2/3 of tongue and palate
To Zanzibar By Motor Car
- temporal
- zygomatic
- buccal
- mandibular
- cervical
*Most frequently paralyzed cranial nerve containing motor fibers*
Muscles of Facial Expression
- Obicularis Occuli
- Occipitofrontalis
- Corrugator Supercilli
- Procerus
- Nasalis
- LLSAN
- Levator Labii Superioris
- Zygomaticus Minor and Major
- Levator Anguli Oris
- Buccinator
- Mentalis
- Depressor Labii inferioris
- Depressor anguli oris
- Orbicularis oris
- Platysma
Orbicularis Oculi
ACTION: Closes eyelids
INNERVATION: CN VII
Occipitofrontalis
ACTION: raises eyebrows & wrinkles skin of forehead; protracts (pulls back) scalp
INNERVATION: CN VII
Corrugator supercilli
ACTION: draws eyebrows medially & down
INNERVATION: CN VII
Procerus
ACTION: depresses medial eyebrow; makes transverse wrinkle in forehead
INNERVATION: CN VII
Nasalis
ACTION: widens nasal aperture during deep inspiration
INNERVATION: CN VII
Levator labii superioris alaeque nasi (LLSAN)
ACTION: everts upper lip and dilates nostrils
INNERVATION: CN VII
Levator labii superioris
ACTION: elevates & everts upper lip
INNERVATION: CN VII
Zygomaticus minor and major
ACTION: elevate upper lip; retract buccal angle, smile!
INNERVATION: CN VII
Levator Anguli Oris
ACTION: raise the buccal angle , one layer deep to levator labii and zygomaticus
INNERVATION: CN VII
Buccinator
ACTION: compress the cheeks against the teeth(eccentric) &/or expelling air when cheeks distended (concentric)
*Deep*
INNERVATION: CN VII
Mentalis
ACTION: wrinkles the chin skin
INNERVATION: CN VII
Depressor Labii Inferioris
ACTION:depresses the lower lip; assist in lower lip eversion
INNERVATION: CN VII
Depressor anguli oris
ACTION: depresses the buccal angle laterally
INNERVATION: CN VII
Orbicularis Oris
ACTION: closes/purses/protrudes the lips, different from obicularis occuli
INNERVATION: CN VII
CN VII Impairments
- If the lesion is near the origin of the nerve or its pathway distally it results in:
- Ipsilateral paralysis of facial & scalp muscles: unable to close the eye; angle of the mouth droops: forehead does not wrinkle
- Loss of taste to anterior 2/3 tongue and palate
- Impairments in secretion of tears and saliva
**Most frequently paralyzed cranial nerve containing motor fibers**
Bell’s Palsy-paralysis of muscles of facial expression; no apparent etiology/idiopathic; suspect edema 2’ infection
Cranial Nerve V (Trigeminal)
PATH: Pons and semilunar (aka trigeminal) ganglion
BRANCHES:
- V1-ophthalmic-primarily sensory
- V2-maxillary-primarily sensory
- V3-mandibular-sensory and motor
RESPONSIBILITIES:
- sensation to face, anterior half of scalp, teeth, mouth, nasal cavity
- motor supply to muscles of mastication
Opthalmic Nerve (V1 of CN V)
PATH: exits cranial vault through superior orbital fissure
BRANCHES:
-lacrimal n.-innervates lacrimal gland (sensory)–>
sensory to conjunctiva(whites of eyes) & skin of upper lid
-frontal n.-divides into supraorbital & supratrochlear ns.->
Supplies sensation forehead, scalp, upper lid, frontal sinus
-Nasociliary n.-major branches = long & short ciliary nerves- will only see on prosection
Contains: sympathetic fibers (not V1 fibers, just take a lil ride) to dilator pupillae; catches a ride with short ciliary nerves
- afferent fibers (sensory) from cornea, skin of eyelid & nose, lacrimal sac, & sinuses
- responsible for the sensory portion of the corneal reflex
- (CN VII responsible for the blink of the eye or the motor response… what muscle?)
- Infratrochlear n.
- Ethmoidal n.
Horner’s syndrome
**Issue with Opthalmic branch of CN V**
-combination of drooping of the eyelid (ptosis) (from paralysis of smooth (tarsal ms (symph) that interdigitate with the levator palpebrae superioris) and constriction of the pulpil (miosis)
-sometimes accompanied by decreased sweating (anhidrosis) of the face on the same side
- redness of the conjunctiva (white of eye) of the eye
- Apparent enophthalmos [posterior displacement of the eyeball within the orbit due to changes in the volume of the orbit (bone) relative to its contents (the eyeball and orbital fat), or loss of function of the orbitalis muscle.]
- indicates problem with the sympathetic nervous system, Medical imaging and response to particular eye drops may be required to identify the location of the problem and the underlying cause.
Maxillary Nerve (V2 of CN V)
PATH: exits foramen rotundum to inferior orbital fissure
BRANCHES:
-infraorbital n.
-meningeal n.
-alveolar ns.
-zygomatic n.- divides into zygomaticotemporal and zygomaticofacial ns.
-Sensory only: supplies skin of face over maxilla, upper lip, maxillary teeth, nose mucosa, maxillary sinus, and palate
Mandibular Nerve (V3 of CN V)
PATH: exits cranial vault through foramen ovale - to temporal fossa
RESPONSIBILITIES: sensation to skin over mandible, teeth/gums of mandible; skin of temporal region; general sensation to ant 2/3 tongue and oral mucosa ; TMJ & motor supply to ms. of mastication—not taste! Just general sensation
- Anterior branch - chiefly motor to mastication:
- Posterior branch- chiefly sensory
branches include auriculotemporal n, buccal n, lingual n (general tongue sensation), & inferior alveolar n. (ends as mental n.)
Trigeminal Neuralgia (Tic Douloureux)
- aka: Tic Douloureux
- Idiopathic trigeminal neuropathy(dysesthesia) (usually sensory in nature)
- Excruciating pain usually along V2 and V3 distribution, chronic pain along V2, V3 until this irritation subsides, can be disabling
- Cause Unknown: ? Vasculature anomaly that compresses CN V maybe
- Treatment: nerve block if long term and chronic; medication, some surgical interventions
Muscles of Mastication
- Masseter
- Temporal
- Medial pterygoid
- Lateral pterygoid
*innervated by CN V (trigeminal), V3 mandibular branch
Masseter
ACTION: powerful elevator of mandible
PROXIMAL: arises from inferior border & med surface of zygomatic arch
-Arch includes zygomatic bone & temporal bone
DISTAL: to the angle and lateral aspect of ramus of mandible
INNERVATION: mandibular branch of CN V (V3)
Temporalis Muscle
ACTION:
- anterior fibers-elevation of mandible (to close mouth & teeth)
- posterior fibers-retract mandible
PROXIMAL: arises from floor temporal fossa & deep temporal fascia
DISTAL: to medial surface, apex, anterior & posterior borders of coronoid process of mandible, & anterior border of ramus of mandible
INNERVATION: mandibular branch of CN V (V3)
Lateral Pterygoid (2 heads)
ACTION: chief protractor; depresses mandible
-Pulls whole articular disc forward, pulling condyle forward which protracts and depresses
PROXIMAL:
- upper-infratemporal surface & crest of greater wing of sphenoid
- lower-lat surface of lat pterygoid plate
DISTAL: ant aspect mandibular neck, articular capsule & TMJ disc
INNERVATION: mandibular branch of CN V (V3)
Medial Pterygoid (2 heads)
ACTION: elevate mandible; protraction of mandible
PROXIMAL: med surface of the lateral pterygoid plate & palatine bone & tuberosity of maxilla
DISTAL: medial surface of mandibular angle
INNERVATION: mandibular branch of CN V (V3)
Movements of Mandible
Elevation: temporalis, masseter, med pterygoid
Depression: lat pterygoid, digastric
Protraction: (protrusion/mandible comes forward)
Lat pterygoid: (prime mover) & med pterygoid
Retraction: (mandible comes backward)
Temporalis: (post fibers)
Lateral Movements
- Ipsilateral:* temporalis & masseter (pull)
- Contralateral:* med & lat pterygoid (push)
- Meaning to move your jaw to your right*: contract R temporalis, R masseter, L medial and L lateral pterygoid
Intratemporal Fossa
§Irregularly shaped deep space located:
- Inferior to the zygomatic arch
- deep to the ramus of the mandible and
- posterior to the maxilla bone
Contents
- Temporalis ms. (Inferior aspect)
- Med and Lat Pterygoid mm.
- Maxillary a. (coming off of external carotid artery) & venous plexus
- Nerves: mandibular, inferior alveolar, lingual, buccal, chroda tympani and otic ganglions
*took out zygomatic arch in this picture*
Temperomandibular Joint (TMJ)
- Diarthrodial (synovial) joint- has joint capsule,
- With synovial fluid that bathes and takes care of itself
- articulation between:
- articular tubercle & mandibular fossa of
temporal bone (in pink)
- & mandibular condyle of mandible (grey)
- complex- bc of articular disc, disc divides joint into 2 separate compartments
- Protraction and retraction occur in the superior compartment
- Elevation and depression occur in the inferior compartment
- To depress mandible: the head of the mandible and articular disc must move anteriorly on the articular surface until the head lies inferior to the articular tubercle
- Loose joint capsule
- Shape- classified differently depending on reference: modified hinge (Moore & Dalley) or bicondylar
Innervation: V3
TMJ Ligaments
•Lateral temporomandibular lig: Thickening of the joint capsule, Prevents posterior dislocation of the jt with the postglenoid tubercle
- Sphenomandibular lig: Connects the lingula of mandible to the cranium via the spine of the sphenoid bone
- Stylomandibular lig: Connects the mandible to the cranium via the styloid process of the temporal bone
TMJ Pathology
Dislocation:
- Posterior: not common
- Anterior (excessive contraction of lat ptyergoids while opening mouth); mandible stays depressed and unable to close mouth
- Clicking: delayed movement of the disc; may indicate tear of disc
Innervation: V3
Extraocular Muscles
Levator palpebrae superioris-elevates upper eyelid
- CN III (oculomotor)
Orbicularis occuli -closes eyelid
-CN VII
Medial Rectus-adduction of eyeball (towards nose)
-CN III (oculomotor)
Lateral Rectus-abduction of eyeball (towards ear)
-CN VI (abducens)
Superior Rectus-elevate eyeball not lid!, adducts (simultaneously), med rotates(intorsion) eyeball
-CN III
Inferior Rectus-depress, adducts, lat rotates(extorsion) eyeball
-CN III
Superior Oblique-depress, abducts, med rotates eyeball (down & out)
-CN IV (trochlear n.)
Inferior Oblique-elevate, abducts, lat rotates eyeball (up & out)
-CN III (oculomotor n.)
LR6 SO4 The rest are 3!
*No one muscle rotates extorsion/intorsion-always combo with other movements*
Levator Palpebrae Superioris
ACTION: elevates upper eyelid
PROXIMAL: Inferior aspect of lesser wing of sphenoid bone
DISTAL:Superior tarsal plate and skin of upper eyelid
INNERVATION: CN III
Medial Rectus
ACTION: adduction of eyeball (towards nose)
INNERVATION: CN III (oculomotor)
Lateral Rectus
ACTION: abduction of eyeball (towards ear)
INNERVATION: CN VI (abducens)
Superior Rectus
ACTION: elevate eyeball not lid!, adducts (simultaneously), med rotates(intorsion) eyeball
INNERVATION:CN III
Inferior Rectus
ACTION: depress, adducts, lat rotates(extorsion) eyeball
INNERVATION: CN III
Superior Oblique
ACTION: depress, abducts, med rotates eyeball (down & out)
INNERVATION: CN IV (trochlear n.)
**Trochlea changes line of pull of superior oblique- so when it tightens, it flips the eyeball down- down bc pulls towards the trochlea
Inferior Oblique
ACTION: elevate, abducts, lat rotates eyeball (up & out)
INNERVATION: CN III (oculomotor n.)
Lesion of CN VI
- Denervation of lateral rectus ms.
- gaze directed medially
Lesion of CN IV
- Denervation of superior oblique muscle
- cannot depress the eye when eye adducted (eg during convergence when reading or going down stairs; double vision) when going downstairs or looking down at book
LEsion of CN III
- Denervation of: levator palpebrae superioris, superior rectus, inferior rectus, medial rectus, inferior oblique
- gaze directed down & laterally b/c only muscles left innervated (LR & SO) produce down and out
Ptosis of the eyelid (droopy eyelid bc levator palpaebrae superioris denervated) & consistent dilated pupil
- CN III responsible for parasymph fibers to sphincter of pupil
- Pupillary reflex lost- sympa fibers dilate pupil, hooked ride with nasocilliary ns (branch of V)
- CN III constricts pupil so if that’s impaired then reflex would be lost
Genioglossus
ACTION: (bilateral) tongue protrusion or protraction (principal muscle); curls the tongue in a circle: unilateral action causes deviation to opposite side
–R genioglossus contraction causes tongue to go to left (b/c the muscle pushes the tongue out to left)
INNERVATION: CN XII
Hyoglossus
ACTION: depresses tongue
Innervation: CN XII
Styloglossus
ACTION: tongue retraction
INNERVATION: CN XII
CN XII Lesions
-CN XII Paralysis-when asked to stick tongue out in midline…deviates to paralyzed side
*(First think of the action: One genioglossus ms. working alone pushes the tongue to the opposite side)
-R XII lesion: when you ask the patient to stick out their tongue, it deviates to the right (b/c the left genioglossus is working alone)
Thorax
- Lodges the heart & lungs
- Skeletal framework comprised of:
- thoracic vertebrae
- intervertebral discs
- ribs
- costal cartilage
- sternum
- Superior thoracic aperture (thoracic inlet)
- Inferior thoracic aperture (thoracic outlet)
Ribs
- 12 paired ribs which protect thoracic & abdominal contents
- increase in length from 1-7; decrease in length 8-12
- 1-7 true ribs connected to sternum by costal cartilage
- 8, 9, 10 join costal cartilage above
- 11, 12 “floating ribs” do not connect to sternum or costal cartilage; but are attached at the costovertebral joints of course!
- Identify: head, neck, tubercle, body, angle of rib
- TV1: articulates with rib 1 superiorly and rib 2 inferiorly
Thoracic Outlet Syndrome
*This area is referred to as the thoracic inlet, but clinically, its referred to as thoracic outlet syndrome, UM OK Y THO?
- signs & symptoms in the head, neck, & arm due to neural or arterial compression in the neck (scalenus anticus syndrome, cervical rib etc.)
- TOS: garbage bucket term for involvement of nerves, arterial & venous supply to UE that results in pain, numbness, tingling, weakness in arm chest, neck
- Causes: anatomical variations, physical trauma, tumors, poor posture, repetitive arm movements, sports.
Abdomen
- Abdominal cavity lies between the thorax & pelvis
- contains most of the digestive system & part of the urogenital system
Anterolateral Abdominal Wall
- 2 recti abdomini anteriorly
- Laterally: external oblique, internal oblique, transversus abdominus ms. (superficial to deep)
- each separated by a layer of fascia
- fascia covering the abdominal wall=Ext Oblique fascia
Thoracoabdominal Nerves
- T7-T11 intercostal nerves (Intercostal nerve underneath each rib [ventral ramus in thoracic region]) change their name as they leave the rib space and turn into thoracoabdominal ns.
- Innervate muscles of the lateral and anterior abdominal wall
- Provide Sensation-via cutaneous branches that pierce the Anterior Rectus sheath & lateral wall
- are ventral rami with both motor and sensory responsibilities
**12th ventral ramus below the last rib, cant be intercostal n, is a T12 ventral ramus**
External Intercostals
ACTION: *Still controversial however evidence suggests it elevates the rib
PROXIMAL:From lower margins of ribs 1-11; fibers pass down & forwards
DISTAL:
To upper margins of rib below
N.B. Extend from tubercles of the rib (post); at costal cartilage become membranous and continues as membranous until the costochondral junction (ant)
INNERVATION: Corresponding intercostal ns.