Anatomy: Head and Neck Flashcards
where does the hyoid bone lie?
anterior to the neck around C3 level
how is the hyoid bone attached to the skeleton
there are no articulations, it is suspended by muscles that connect to the mandible, styloid process of temporal bone, thyroid cartilage, manubrium of the sternum and the scapula
what does the hyoid bone contain
a body and 2 greater and 2 lesser horns
what does the hyoid bone do?
provides a moveable base for the tongue and helps keep the pharynx patent (needed for swallowing and respiration)
what 2 ligaments support the hyoid in place?
stylohyoid ligament and thyrohyoid membrane
stylohyoid ligaments
attach to the lesser horns of the hyoid bone and suspend the hyoid from the styloid processes
thyrohyoid membrane
acts as a strong anchor to the hyoid bone to the thyroid cartilage
subcutaneous fascia is found?
below the skin of the neck
what part of the subcutaneous fascia contains the platysma muscle?
the anterolateral part
the fibers of the platysma diverge and leave a gap anterior to what two structures?
the larynx and trachea
name the 3 layers of deep cervical fascia
- investing fascia
- pretracheal fascia
- prevertebral fascia
where is the investing cervical fascia found?
immediately deep to the subcutaneous fascia.
It is the most superficial deep layer of fascia that surrounds the entire neck
what muscles are enclosed by the investing cervical fascia?
the trapezius and the sternocleidomastoid muscles
what is the investing cervical fascia continuous with?
the nuchal ligament
what does the investing cervical fascia connect to superiorly?
the superior nuchal lines of the occipital bone, mastoid processes of the temporal bone, zygomatic arches, inferior border of the mandible, the hyoid bone and the spinous processes of the cervical processes
what does the investing cervical fascia connect to inferiorly?
it remains divided in two layers to enclose the SCM. One layer attaches to the anterior and the other to the posterior surface of the manubrium
what is the space called formed by the two inferior layers of the investing cervical fascia?
the suprasternal space
what is enclosed in the suprasternal space
the inferior ends of tha anterior jugular veins, the jugular venous arch, fat, and lymph nodes
what is the most superior landmark on the sternum?
the jugular notch
where is the pretracheal fascia found?
lies in the anterior part of the neck, deep to the inesting fascia
what does the pretracheal fascia blend with inferiorly?
the fibrous pericardium of the heart in the thorax
what is enclosed in the muscular part of the pretracheal fascia?
the infrahyoid muscles
what is enclosed in the visceral part of the pretracheal fascia?
the thyroid gland, trachea, and esophagus
what is the visceral part of the pretrachael fascia continuous with posteriorly and superiorly?
buccopharyngeal fascia of the pharynx
what does the pretrachael fascia blend with laterally?
the carotid sheaths
superior to the hyoid what forms a pulley through the intermediate tendon of the digastric muscle passes suspending the hyoid bone?
a thickening of pretrachael fascia
what is tethered to the two bellied omohyoid muscles?
pretrachael fascia
where is the prevertebral layer of deep cervical fascia?
fixed to the cranial base superiorly.
what does the prevertebral fascia form?
a tubular sheath for the vertebral column and the muscles associated with it (longus colli, longus capitis, scalenes, and deep cervical muscles)
what does the prevertebral fascia blend with inferiorly?
endothoracic fascia peripherally and fuses with the ALL centrally around T3
what does the prevertebral fascia extend with laterally?
the axillary sheath to then form the axillary fascia
what is surrounded by the axillary sheath?
axillary artery, axillary vein, and the brachial plexus
where are the prevertebral muscles contained?
directly within the prevertebral fascia attaching to the cervical vertebrae
prevertebral muscles:
longus colli, longus capitis, rectus capitis anterior, rectus capitis lateralis, anterior scalenes, middle scalenes, and posterior scalenes
what is horner syndrome?
upper thoracic neck masses can compress the sympathetic chain resulting in miosis, ptosis, anhidrosis and vasodilation of the ipsilateral face
where does the carotid sheath extend from?
it is a fascial tube that extends from the cranial base to the root of the neck
what does the carotid sheath blend with anteriorly?
the investing and pretrachael layers of fascia
what does the carotid sheath blend with posteriorly?
the prevertebral fascia
what is contained in the carotid sheath?
the common and internal carotid arteries, the internal jugular vein, the vagus nerve, some deep cervical lymph nodes, the carotid sinus nerve, and sympathetic nerve fibers
which is the largest and most important space in the neck?
the retropharyngeal space
where is the retropharyngeal space?
behind the pharynx
what is the retropharyngeal space?
a space filled with loose connective tissue between the pretrachael and prevertebral layers just posterior to the esophagus
what is the retropharyngeal space continuous with?
the superior mediastinum
if there was an abscess in the pharynx and it eroded where could it potentially go?
in the retropharyngeal space
an abscess in the retropharyngeal space may make what two activities difficult?
swallowing (dysphagia) and speaking (dysarthria)
what does the sternocleidomastoid region divide?
the neck into anterior and lateral regions
what are the contents of the sternocleidomastoid region?
the sternocleidomastoid, the superior part of the external jugular vein, the greater auricular nerve, and the transverse cervical nerve
what space do the two heads of the sternocleidomastoid separate inferiorly?
lesser supraclavicular fossa
what vein resides deep in the supraclavicular fossa?
the internal jugular vein
name the cutaneous and superficial muscles of neck
platysma muscle, sternocleidomastoid, and trapezius
what are the boundaries of the posterior cervical region?
the anterior edge of the trapezius, the midline of the body, and the horizontal fibers of the trapezius
what are the contents of the posterior cervical region?
the trapezius muscle, the cutaneous branches of the posterior rami of cervical spinal nerves and the suboccipital triangle (lies deep)
lateral cervical region (aka posterior triangle) anterior boundary
posterior border of SCM
lateral cervical region posterior boundary
posterior border of trapezius
lateral cervical region inferior boundary
middle 1/3 of of clavicle (between trap and SCM)
lateral cervical region apex
where the SCM and trap meet on superior nuchal line of occipital bone
lateral cervical region roof
formed by the investing layer of the deep cervical fascia
lateral cervical region floor
formed by the muscles covered by the prevertebral layer of fascia (spelnius muscles, levator scap, posterior and middle scalenes
what two triangles can the the lateral cervical region be split into but the inferior belly of the omohyoid?
superiorly: occipital triangle
inferiorly: omoclavicular triangle
what are the contents of the occipital triangle?
occipital artery. spinal accessory nerve is not a content but does cross over the traingle
what are the contents of the omoclavicular (subclavian) triangle?
the inferior external jugular vein crosses superficial and the subclavian artery lies deep within
arteries of the lateral cervical region
occipital artery, subclavian artery
what does the occipital artery branch off of
external carotid artery
what is the course of the occipital artery?
enters the lateral cervical region at its apex and goes up over the head to supply the posterior part of the scalp
what does the subclavian artery supply?
the upper limb as well as the neck and brain
Where does the right subclavian artery arise from?
the brachiocephalic trunk
where does the left subclavian artery arise from?
directly off the arch of the aorta (to the left of the left common carotid artery)
where do both the left and right subclavian arteries enter?
the sternoclavicular joint
what muscle divides the subclavian artery into 3 parts?
the anterior scalene
how does the subclavian artery divide?
a medial, posterior and lateral part
what is contained in the medial part of the subclavian artery division?
the vertebral artery, internal thoracic artery, and the thyrocervical trunk
what is contained in the posterior part of the subclavian artery division?
costocervical trunk
what is contained in the lateral part of the subclavian artery division?
dorsal scapular artery
where does the right part of the vertebral artery arise from?
the first part of the subclavian artery rises up through the pyramidal space formed by the scalene and longus colli muscles
where does the vertebral artery enter?
the transverse forearm of the transverse processes of C6-C1
what does the suboccipital part of the vertebral artery course over?
the groove for the vertebral artery on the arch of C1
where does the suboccipital part of the vertebral artery enter?
the cranium through the foramen magnum
when does the suboccipital part of the vertebral artery become the cranial part of the vertebral artery?
when it passes through the foramen magnum into the cranium
what does the cranial part of the vertebral artery supply?
branches to the medulla, spinal cord, parts of the cerebellum, and the dura of the posterior cranial fossa
when do the vertebral arteries come together?
at the inferior order of the pons of the brainstem
what do the vertebral arteries form when they come together?
the basilar artery
where does the internal thoracic artery arise from
the anterior superior aspect of the first part of the subclavian artery
where does the internal thoracic artery pass?
inferomedially to the thorax
what does the thyrocervical trunk give rise to?
suprascapular artery, ascending cervical artery, and inferior thyroid arteries