Osteology |
|---|
| Bone/Cartilage |
Structure |
Description |
Notes |
|
occipital (N8, TG7-06) |
|
the bone forming the posterior surface of the skull |
it articulates superolaterally with the parietal bones through the lambdoid
suture, anteroinferiorly with the temporal bone and anteriorly with the body
of the sphenoid bone |
|
foramen magnum |
the opening in the occipital bone posterior to the basal part |
it transmits the spinal cord, two vertebral aa., and two spinal accessory
nerves |
|
hypoglossal canal |
an opening in the lateral part of the occipital bone |
paired; it transmits the hypoglossal nerve |
|
occipital condyle |
a low, wide projection from the inferior surface of the lateral part of
the occipital bone |
paired; it articulates with the atlas |
|
jugular notch |
a notch located on the anterolateral edge of the lateral part of the occipital
bone |
it forms the posterior margin of the jugular foramen; the temporal bone
forms the anterior margin of the jugular foramen |
| temporal |
|
bone forming the lateral side of the skull |
(Latin, temporis = of time. Temporal refers the passage of time, which is marked by the appearance of gray hair on the side of the head) |
|
petrous part (TG7-08) |
the hard part of the temporal bone located in the floor of the cranial cavity |
it contains the tympanic cavity (middle ear) and the bony labyrinth of the
inner ear |
|
carotid canal (TG7-06) |
a canal which courses through the petrous part of the temporal bone |
it transmits the internal carotid a. and the internal carotid plexus of
nerves into the cranial cavity |
|
styloid process (TG7-06) |
the spike of bone that projects inferiorly from the petrous part of the
temporal bone |
it is the attachment site for the stylohyoid, styloglossus and stylopharyngeus
mm. and the stylomandibular and stylohyoid ligaments |
| rib 1 (N186, TG4-04) |
|
the most cephalic rib |
it is the broadest, shortest and widest of the ribs; the scalene tubercle
marks its superior surface and is an elevation between grooves for the subclavian
vein & artery; the scalene tubercle is the attachment site of the scalenus
anterior m. |
| cervical vertebrae (N18, TG1-04) |
|
the seven vertebrae of the neck |
cervical vertebrae have the features of the typical vertebra plus all have
transverse foramina (for passage of the vertebral artery); C2-C6 have bifid
spinous processes; cervical vertebrae have relatively small bodies; several
cervical vertebra are named: atlas, axis, vertebra prominens |
Muscles |
|---|
| Muscle | Origin | Insertion | Action | Innervation | Notes | Image |
|---|
| scalene, anterior (N28, N30, N32, TG7-15A, TG7-15B, TG7-17, TG7-18) | anterior tubercles of transverse processes of vertebrae C3-C6 | scalene tubercle of first rib | elevates first rib; flexes and laterally bends the neck | brachial plexus, C5-C7 | a muscle of inspiration; anterior scalene inserts behind the subclavian vein, and anterior to the subclavian artery and roots of the brachial plexus (Greek, skalenos = uneven, having sides of unequal length) |  |
| scalene, middle
(N28, N30, N32, TG7-15A, TG7-15B, TG7-17, TG7-18) | posterior tubercles of the transverse processes of vertebrae C2-C7 | upper surface of first rib behind subclavian artery | elevates first rib; flexes and laterally bends the neck | brachial plexus, C3-C8 | a muscle of respiration (inspiratory); also called scalenus medius; penetrated by the dorsal scapular n. and long thoracic n. (Greek, skalenos = uneven, having sides of unequal length) |  |
| scalene, posterior (N28, N30, N32, TG7-15A, TG7-15B, TG7-17, TG7-18) | posterior tubercles of the transverse processes of vertebrae C5-C7 | lateral surface of second rib | elevates second rib; flexes and laterally bends the neck | brachial plexus, C7-C8 | a muscle of respiration (inspiratory); the longest of the scalene muscles (Greek, skalenos = uneven, having sides of unequal length) |  |
| constrictor, superior pharyngeal (TG7-19) |
medial pterygoid plate, pterygoid hamulus, pterygomandibular raphe, mylohyoid line of mandible |
pharyngeal tubercle and midline pharyngeal raphe |
constricts the pharyngeal cavity |
vagus (X), via pharyngeal plexus |
none |
 |
| constrictor, middle pharyngeal (TG7-19) |
lesser and greater horns of hyoid bone and inferior part of the stylohyoid ligament |
midline pharyngeal raphe |
constricts the pharyngeal cavity |
vagus, via pharyngeal plexus |
none |
 |
| constrictor, inferior pharyngeal (TG7-19) |
oblique line of thyroid cartilage, lateral surface of cricoid cartilage |
midline pharyngeal raphe |
constricts pharyngeal cavity |
vagus (X), via pharyngeal plexus, with aid from superior laryngeal and recurrent laryngeal nerves |
most external of the three pharyngeal constructor mm. |
 |
| stylopharyngeus (TG7-19) |
medial side of styloid process |
superior border of thyroid cartilage and also into the pharyngeal wall |
elevates the larynx |
glossopharyngeal nerve (IX) |
stylopharyngeus, the only muscle innervated by IX, is the only pharyngeal muscle NOT innervated by vagus (X) nerve |
 |
Nerves |
|---|
| Nerve | Source | Branches | Motor | Sensory | Notes |
|---|
| glossopharyngeal (TG7-19) |
medulla: spinal trigeminal nucleus from superior ganglion (GVA); nucleus solitarius from inferior ganglion (SVA); nucleus ambiguus (GVA); inferior salivatory nucleus (GVE preganglionic parasympathetic) |
tympanic nerve to tympanic plexus & lesser petrosal n., carotid sinus n., stylopharyngeus brs., pharyngeal brs. |
GSE: stylopharyngeus; GVE: secretomotor to parotid gland (preganglionic parasympathetic via tympanic n. to lesser petrosal n. to otic ganglion, postganglionic parasympathetic via auriculotemporal n.) |
GVA: carotid body & sinus, pharynx, middle ear; GSA: skin of external ear; SVA: taste from posterior 1/3rd of tongue |
also known as: CN IX, 9th cranial nerve; passes through jugular foramen; may penetrate the stylopharyngeus m. |
| hypoglossal (TG7-19) |
medulla: hypoglossal nucleus |
branches of C1 carried by this nerve are not considered to be branches of the hypoglossal nerve |
intrinsic and extrinsic muscles of the tongue (except palatoglossus m.) |
|
also known as: CN XII, 12th cranial nerve; passes through the hypoglossal canal; superior root of ansa cervicalis travels with the hypoglossal n. |
| cervical plexus | ventral primary rami of C1-C4 spinal nerves | brs. to: longus colli & capitis, sternocleidomastoid, trapezius, levator scapulae, scalenus medius, rectus capitis anterior & lateralis: superior & inferior root of ansa cervicalis, n. to thyrohyoid, n. to geniohyoid, lesser occipital, great auricular, transverse cervical, supraclavicular nn. (medial, intermediate & lateral), contribution to phrenic n. | longus colli & capitis, rectus capitis anterior & lateralis, infrahyoid mm., thyrohyoid, geniohyoid, diaphragm | skin of neck anterolaterally; skin of ear & behind ear | close association of supraclavicular nn. to phrenic n. results in pain from diaphragm referred to shoulder (Latin, plexus = a braid) |
| accessory N71,
N127, TG7-18, TG7-93) | cranial root: nucleus ambiguus; spinal root: spinal nucleus of upper cervical spinal cord | cranial root joins vagus; spinal root ascends through foramen magnum | GSE: sternocleidomastoid and trapezius mm. | | also known as: CN XI, 11th cranial nerve; passes through jugular foramen; accessory n. is motor only; proprioceptive fibers reach sternocleidomastoid via C2&C3 and trapezius via C3&C4 (subtrapezial plexus) |
| vagus
(TG7-21) | medulla: dorsal nucleus (GVA & GVE preganglionic parasympathetic) from inferior ganglion, nucleus ambiguus (SVE); spinal trigeminal nucleus (GSA) from superior ganglion; nucleus solitarius (SVA) from inferior ganglion | auricular br., pharyngeal br., superior laryngeal, superior & inferior cervical cardiac brs., recurrent laryngeal, thoracic cardiac brs., brs. to pulmonary plexus, esophageal plexus, anterior & posterior vagal trunks | SVE: intrinsic muscles of larynx, pharynx (except stylopharyngeus), & palate (except tensor veli palatini); GVE: smooth muscle of respiratory tree & gut (proximal to splenic flexure), heart; secretomotor: mucous glands of larynx, respiratory tree, pharynx & gut, digestive glands | GSA: skin of external auditory meatus; GVA: viscera of head, neck, thorax & abdomen proximal to splenic flexure; SVA: taste to epiglottis | also known as: CN X, 10th cranial nerve; passes through jugular foramen; (Latin, vagus = wanderer because of its wide distribution to the body cavities) |
| pharyngeal plexus |
motor contributed by the vagus n. (X); sensory contributed by the glossopharyngeal
n. (IX), vasomotor contributed by the superior cervical sympathetic ganglion |
no named branches |
vagus: all muscles of the pharynx except stylopharyngeus; sympathetic: smooth
muscle in the pharyngeal vasculature |
glossopharyngeal: mucous membrane lining the pharynx |
the muscles of the pharyngeal wall are skeletal m. derived from the mesenchyme of the 4th pharyngeal arch (Latin, plexus = a braid) |
| superior laryngeal (TG7-21) |
vagus (X) |
internal & external brs. |
cricothyroid, inferior pharyngeal constrictor, secretomotor to mucous glands of larynx above vocal folds |
mucous lining of larynx above vocal folds |
external br. supplies cricothyroid m.; all other intrinsic muscles of the larynx are supplied by the recurrent laryngeal nerve |
| cardiac (N130, TG7-15, TG7-95) |
vagus (X); cervical sympathetic trunk |
|
heart (parasympathetic: decreases rate & force of contraction; sympathetic: increases rate & force of contraction); bronchial tree & lungs via pulmonary plexus |
heart, bronchial tree & lungs |
vagus has 2 (superior & inferior) cervical cardiac brs. & 1 or more thoracic br.; cervical sympathetic trunk usually gives 3 (superior, middle & inferior) cardiac brs. |
| to carotid body |
vagus (X) & glossopharyngeal (IX) |
|
chemoreception (blood pH) in carotid body; blood pressure recerptors in carotid sinus; both located near bifurcation of common carotid a. |
|
|
| phrenic (N30, N193, TG4-18, TG7-15) | ventral primary rami of C3-C5 (cervical plexus) | pericardial brs. | diaphragm | pericardium; mediastinal, diaphragmatic & costal pleura | crosses the anterior surface of the anterior scalene m. (Greek, phrenic = diaphragm) |
| sympathetic chain ganglia, cervical (N129, N130, TG7-15, TG7-95) | preganglionic sympathetic via ascending fibers from T1-T5 | postganglionic sympathetic via gray rami communicans to cervical spinal nn.; internal & external carotid nn.; cervical cardiac brs. | dilator pupillae m.; vascular smooth muscle; arrector pili muscles & sweat glands of head and neck; heart & lungs | pain from viscera | located parallel & lateral to vertebral bodies in neck; there are no white rami communicans at cervical levels |
| carotid plexus, external (N130, TG7-15, TG7-95) |
superior cervical ganglion of the sympathetic trunk, via external carotid n. |
distributes along external carotid artery brs. |
vascular smooth muscle, arrector pili muscles, sweat glands of face & upper neck |
|
postganglionic sympathetic nerve fibers use arteries as roadways to enter the head and neck (Latin, plexus = a braid) |
| carotid plexus, internal (N130, TG7-15, TG7-95) |
superior cervical ganglion of sympathetic trunk, via internal carotid n. |
most distribute along the internal carotid artery brs., although deep petrosal n. is an exception |
vascular smooth muscle of brain, orbit, forehead, upper nasal cavity; arrector pili muscles of forehead & ant. scalp; sweat glands of forehead; dilator pupillae |
|
postganglionic sympathetic nerve fibers use arteries as roadways to enter the head and neck (Latin, plexus = a braid) |
| recurrent laryngeal (N75, N232, TG7-14, TG7-20) | vagus (X) | esophageal brs., tracheal brs., cardiac brs., pharyngeal brs., inferior laryngeal n. | upper esophagus, lower pharynx, laryngeal ms. (except cricopharyngeus); smooth muscle of trachea; secretomotor to mucous glands in upper esophagus, lower pharynx, larynx below vocal fold, trachea; cardiac muscle of heart (slows rate, decreases force of contraction) | upper esophagus, lower pharynx, larynx below vocal folds, GVA from heart | right recurrent loops posteriorly around right subclavian a.; left recurrent loops posteriorly around aortic arch & ligamentum arteriosum; inferior laryngeal br. supplies all intrinsic muscles of the larynx EXCEPT cricothyroid m. |
| brachial plexus (N30, N430, TG7-14, TG2-14) | ventral primary rami of C5-8 & T1 | dorsal scapular, long thoracic, n. to subclavius, suprascapular, lateral & medial pectoral, medial brachial & antebrachial cutaneous, upper, middle & lower subscapular, musculocutaneous, ulnar, median, axillary, radial | muscles of upper limb, excluding trapezius | skin of upper limb | plexus is a latin word meaning "braid"; axons from spinal cord levels C5-T1 are mixed (braided) in the brachial plexus and repackaged into terminal branches so that each branch contains axons from several spinal cord levels (Latin, plexus = a braid) |
| dorsal scapular (N430, N477, TG2-14, TG2-13) | brachial plexus (C5) | | rhomboid major & minor; levator scapulae | no cutaneous branches | passes through scalenus medius |
| long thoracic (N429, N430, TG2-14, TG2-13) | brachial plexus (C5-C7) | | serratus anterior | no cutaneous branches | located on superficial surface of serratus anterior; lesion causes scapular winging, hence the saying "C5, 6, & 7 keep the wings from heaven" |
| suprascapular (N424,N430, N477, TG2-14, TG2-13) | superior trunk of brachial plexus (C5-C6) | | supraspinatus, infraspinatus | no cutaneous branches | passes through scapular notch inferior to the superior transverse scapular ligament |
Arteries |
|---|
| Artery | Source | Branches | Supply | Notes |
|---|
| subclavian (N33, N136, TG7-15A, TG7-15B) | brachiocephalic (right), aortic arch (left) | 1st part: vertebral, thyrocervical trunk, internal thoracic; 2nd part: costocervical trunk; 3rd part: dorsal scapular (70%); axillary a. is the continuation at lat. border of rib 1 | neck, spinal cord, thyroid gland & larynx, shoulder, chest muscles, upper limb | ant. scalene muscle passes anterior to subclavian, dividing it into 3 parts |
| common carotid (N69, N136, TG7-19, TG7-71) | brachiocephalic trunk (right), aortic arch (left) | external & internal carotid (terminal brs.) | most of head & upper neck | common carotid a. bifurcates at the level of the superior border of the thyroid cartilage; carotid sinus & body located at bifurcation |
| internal carotid (N69, N136, TG7-19,TG7-72) | common carotid | none in the neck; in the head: ophthalmic, post. communicating, ant. & middle cerebral (terminal brs.) | brain, eye, forehead | primary blood supply to the brain; anastomoses with vertebral aa. |
| external carotid (N69, N136, TG7-19,TG7-71) | common carotid | superior thyroid, ascending pharyngeal, lingual, facial, occipital, post. auricular, maxillary & superficial temporal (terminal brs.) | upper neck, face & scalp | primary blood supply to face & superficial head |
| ascending pharyngeal |
external carotid |
pharyngeal brs., inf. tympanic, post. meningeal |
pharynx |
arises from the medial side of the external carotid a. close to the birfurcation |
| vertebral (N33, N136, TG7-15, TG7-72) | subclavian (1st part) | spinal brs., muscular brs., ant. spinal, post. inf. cerebellar, medullary brs., meningeal brs., basilar (fusion of paired vertebrals) | deep neck, cervical spinal cord, hindbrain | anastomoses with internal carotid in cerebral arterial circle (of Willis); courses through transverse foramina of vertebrae C1-C6 |
| thyrocervical trunk (N33, N136, TG7-15A, TG7-15B) | subclavian, 1st part | inferior thyroid, transverse cervical, suprascapular | lower neck, posterior shoulder, thyroid gland | a short thick trunk |
| cervical, transverse (N33, N184, TG1-13, TG7-14, TG7-15A, TG7-15B) | thyrocervical trunk | muscular | trapezius muscle & surrounding muscles | may give off the dorsal scapular a. (30%) |
| suprascapular (N33, N427, TG2-15, TG7-14, TG7-15A, TG7-15B)
| thyrocervical trunk | muscular | supraspinatus & infraspinatus, shoulder joint | anastomoses with circumflex scapular, dorsal scapular & deep br. of transverse cervical |
| thyroid, inferior (N33, N136, TG7-14, TG7-15A,TG7-15B) | thyrocervical trunk | ascending cervical, inferior laryngeal, esophageal brs., tracheal brs., glandular brs. | thyroid gland, lower larynx, upper trachea & esophagus, neck muscles | |
| thoracic, internal (N33, N136, TG7-15A, TG7-15B, TG4-09) | subclavian, 1st part | anterior intercostal aa., musculophrenic, superior epigastric | anterior chest wall, anterior portion of intercostal spaces | commonly called "internal mammary" in clinical settings |
| costocervical trunk (N33, N130, TG7-14, TG7-15A, TG7-15B) | subclavian, 2nd part | deep cervical & supreme intercostal | muscles of neck posteriorly; first 2 posterior intercostal spaces | located between anterior & middle scalene muscles |
| scapular, dorsal (N33, N410, TG2-09, TG7-14, TG7-15A, TG7-15B) | subclavian, end of 3rd part | muscular | levator scapulae, rhomboideus major & minor mm. | anasotmoses with suprascapular & subscapular aa.; a branch of the transverse cervical a. in 30% of cases |
Clinical Terms
|
|
Term
|
Definition
|
| subclavian "stick"/central venous line catheterization |
the right subclavian vein is often the point of entry to the
venous system for central line placement to administer parenteral (nutritional) fluids and medications and to measure
central venous pressure. When using the infraclavicular
approach, the physician inserts the needle along the inferior surface of the middle
part of the clavicle and moves it medially toward the jugular notch in the
manubrium and along the posterior surface of the clavicle where the subclavian
vein ascends. If the needle is not inserted carefully, it may tear the subclavian
vein and parietal pleura, resulting in hemothorax (bleeding into the pleural
cavity). Furthermore, if the needle goes too far posteriorly, it may enter the
subclavian artery. Once the needle is inserted, a soft, flexible catheter is inserted
into the subclavian vein to be used as a guide. |
| thoracic outlet syndrome |
condition due to compromise of blood vessels or nerve fibers between the armpit (axilla) and base of the neck. |
| cervical rib |
a rib which arises from the seventh cervical vertebrae (above the normal first rib). Occurs in only about 0.5% of people. May cause nerve and artery problems |
| scalenus anticus syndrome |
a syndrome in which the nerves and vessels (lower brachial plexus and subclavian artery) passing between the anterior scalene muscle and a cervical rib are compressed causing pain over the shoulder and radiating down the arm or over the back of the neck. |
| subclavian steal syndrome |
aortic arch syndrome, also referred to by many as vertebral-basilar artery
disease, carotid artery occlusive syndrome and subclavian steal syndrome is
characterized by a constellation of signs and symptoms which occur secondary
to abnormalities in the major arteries which extend off of the aortic arch. These
abnormalities are structural and most often secondary to the effects of
atherosclerosis, blood clots, trauma or a congenital abnormality. Symptoms of
this condition include various neurologic symptoms, reduction in pulse and
changes in blood pressure. |
| Virchow's node |
also called a signal node. An enlarged supraclavicular lymph node, usually on the
left side, which is often the first sign of an abdominal tumor (such as stomach
cancer). |
| carotid stenosis & endarterectomy |
carotid stenosis is a result of atherosclerotic thickening of the intima of the carotid artery. Partial occlusion of this artery may cause transient ischemic attack - a sudden focal loss of neurological function (e.g., dizziness and disorientation) that disappears within 24 hours. Arterial occlusion can also lead to a minor stroke - loss of neurological function such as weakness or sensory loss on one side of the body that exceeds 24 hours but disappears within 3 weeks. The symptoms resulting from carotid stenosis depend on the degree of bloodflow obstruction. To help the situation endarterectomies are performed in which part of the athersclerotic plaque on the intima is stripped off. The common site for this procedure is the internal carotid artery just superior to its origin. Drugs are administered after the procedure to inhibit clot formation. Cranial nerve injury can occur during this procedure to the following nerves: glossopharyngeal, vagus, accessory, hypoglossal, and superior laryngeal nerves. (Greek, stenosis = a narrowing) |
| radical neck dissection |
the most commonly performed major operation for head and neck malignancies, most of which are squamous cell carcinomas. The neck is opened laterally, the majority of the sternocleidomastoid muscle is removed, as are the regional cervical lymph nodes, the jugular vein, the spinal accessory nerve, the submaxillary gland and most of the parotid gland. There are several modifications. |
| Horner's syndrome |
nerve condition which involves a drooping eyelid (ptosis), constricted pupil (miosis),
enophthalmos and lack of sweating on one side of the face. Often seen in association
with injury (for example neck fracture, penetrating injury) to the cervical sympathetic
nerve trunk in the neck or a Pancoast tumor (tumor of the cupula region) involving both the upper and lower
brachial plexus. |
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