Quiz 2 Flashcards
What is the neck and what are its functions?
fibromuscular tube that connects the head with the thorax. Its functions include being a passageway for a portion of the respiratory system (the larynx and trachea start in the neck and end in the lungs), is a passageway for portions of the digestive system (the esophagus connects the pharynx to the stomach), is a passage of the brachial plexus from the neck into the upper limb, it is the location of the thyroid and parathyroid endocrine glands, and includes muscle activities such as 1) movement of the head on the neck, 2) stabilizing the head on the neck, 3) movements of the neck, 4) inspiration, 5) deglutition
What are the bones in the neck?
1) cervical vertebrae, which protect the spinal cord and vertebral artery, serve as attachments for muscles, and assist with movement. 2) the hyoid bone, which is an attachment for muscles (especially those of the tongue and pharynx)
What are the regions of the neck?
1) Posterior Neck (contains postural muscles that are innervated by the dorsal rami). 2) Anterior and lateral neck (which divide the region into the posterior and anterior triangles)
What are the boundaries of the posterior triangle?
The posterior border of the sternocleidomastoid, the anterior border of the trapezius, and the middle portion of the clavicle
What are the primary contents of the posterior triangle?
1) spinal/accessory portion of cranial nerve XI, 2) cutaneous branches of cervical plexus of nerves, 3) phrenic nerve
What are the boundaries of the anterior triangle?
the anterior border of the sternocleidomastoid, and the mandible.
What are the primary contents of the anterior triangle?
the hyoid bone (level of C3), thyroid cartilage (part of both larynx and pharynx– C4-C5), cricoid cartilage (primary cartilage of the larynx– C6), superior portion of the trachea, and thyroid glands (C5 to T1 and covered by infrahyoid muscles), submandibular salivary gland
How can the thyroid cartilage be easily identified?
It has a prominent projection, the laryngeal prominence (Adam’s apple)
What is the vertebral level of the hyoid bone?
C3
What is the vertebral level of the thyroid cartilage?
C4-C5
What is the vertebral level of the cricoid cartilage?
C6
What is the vertebral level of the thyroid gland?
C5-T1
What is the carotid sheath?
A fascial sheath that is found deep to the sternocleidomastoid muscle. It contains the internal jugular vein, common and internal carotid arteries, deep cervical lymph nodes, carotid sinus nerve, sympathetic nerve fibers, and the vagus nerve. Communicates with the mediastinum of the thorax and the cranial cavity, which are pathways for the spread of infection.
What is the viscera contained in the neck?
larynx, trachea, esophagus, thyroid and parathyroid glands
What determines the direction in which an infection in the neck may spread?
Fascial planes
What is the platysma?
A broad, thin sheet of muscle. Muscle of facial expression that arises in subcutaneous tissue covering the superior parts of the deltoid and pectoralis major muscle and sweeps superomedially over the clavicle to the inferior border of the mandible.
What does deep cervical fascia consists of and what do they allow for?
Three fascial layers: investing pretracheal, and prevertebral, which support the viscera, muscles, vessels, and deep lymph nodes. The fascial layers privode the slipperiness that allows structures in the neck to move and pass over one another without difficulty, such as when you swallow.
What is the advantage of natural cleavage planes and what forms them?
They are formed by the layers of the deep cervical fascia. The natural cleavage planes allows for separation of tissues during surgery.
Describe the investing layer of deep cervical fascia.
Most superficial layer. Surrounds the entire neck. Deep to subcutaneous tissue. At the four corners of the neck, the investing layer splits into superficial and deep layers of deep fascia to encole the right and left SCM and trapezius. Superiorly, it attaches to the superior nuchal line of the occipital bone, mastoid processes, zygomatic arches, inferior border of the mandible, hyoid, and spinous processes. Just inferior to the mandibular attachment, it splits to enclose the submandibular gland. Posterior to the mandible, it splits to form the fibrous capsule of the parotid gland. Inferiorly, it attaches to the manubrium, clavicles, acromions, and scapular spines. It covers the C7 spinous process and the nuchal ligament. It is divided into two layers that enclose the SCM. A suprasternal space lies between these layers and encloses tthe inferior ends of the anterior jugular veins and lymph nodes.
Describe the pretracheal layer of deep cervical fascia
The pretracheal layer of deep cervical fascia is limited to the anterior part of the neck. It extends inferiorly from hyoid to the thorax, where it blends with the fibrous pericardium covering the heart. It includes the thin muscular part (encloses the infrahyoid muscles) and a visceral part, which encloses the thyroid gland, trachea, and esophagus. Continuous with the buccopharyngeal fascia and blends with carotid sheaths.
Describe the prevertebral layer of deep cervical fascia.
Forms tubular sheath for the vertebral column and the muscles associated with it, Fuses with the anterior longitudinal ligamnt at T3. Extends as the axillary sheath, which surrounds the axillary vessels and the brachial plexus.
Describe the retropharyngeal space.
permits movement of the pharynx, esophagus, larynx, and trachea relative to the vertebral column during swallowing. Largest and most clinically important space in the neck because it is the major pathway for the spread of infection.
What helps prevent the spread of abscesses?
the investing layer of deep cervical fascia.
What separates the sternal and clavicular heads of the sternocleiodomastoid?
the lesser supraclavicular fossa
What is torticollis?
a contraction of the cervical muscles that produces a twisting of the neck and slanting of the head. Can be congenital (results from a fibrous issue tumor that develops in the SCM, or the SCM is injured when an infant’s head is pulled excessively during a difficult birth. This tearing results hematoma that may develop into a fibrous mass entrapping a branch of CN XI, which would denervate part of the SCM). Spasmodic torticollis, which begins in adulthood, involves bilaterial combination of lateral neck muscles (especially SCM).
What are the superficial muscles of the neck?
The platysma, the trapezius, and the sternocleidomastoid
What are the infrahyoid muscles?
4 thin muscles found on either side of hte midline of hte neck, inferior to the hyoid bone. All attach to the hyoid and help depress the hyoid after swallowing. Also steady the hyoid bone so that the muscles of the tongue and pharynx can use the hyoid bone as a strut when they contract. They are innervated by C1-C3 (ansa cervicalis) and include the sternohyoid, omohyoid, sternothyroid, and thyrohyoid.
What are the suprahyoid muscles?
The suprahyoid muscles lie superior to the hyoid bone. Involved with the process of swallowing, depressing the mandible when opening the mouth wide, and protrusion of the tongue.
What innervates the sternocleidomastoid?
Cranial Nerve XI
Why is the SCM an important landmark?
It can be used to find the carotid artery pulse and locating the brachial plexus when attempting to perform brachial plexus nerve block.
Where are the suprahyoid muscles located and what do they do?
Suprahyoid muscles lie superior to hyoid bone. They are involved with the process of swallowing, depressing the mandible when opening the mouth wide, and protrusion of the tongue.
Which movements of the neck do not involve the 7 cervical vertebrae?
none.
What are the five groups of muscles of the anterior neck?
Superficial, Infrahyoid, Suprahyoid, Lateral vertebral
Prevertebral
What are the muscles of the suprahyoid?
mylohyoid, digastric, geniohyoid, and stylohyoid.
What are the two muscles of contralateral rotation in the neck area that we have learned about so far?
semispinalis capitis and sternocleidomastoid
What are the muscles of the lateral vertebral group? what is their action, origin and insertion, and innervation?
Middle, Anterior, and Posterior Scalene. All of which originate from the anterior tubercles of the 3rd through the 7th cervical vertebrae and are innervated by motor branches from cervical nerves C3-C8. Acting bilaterally, they flex the neck. When the neck is steadied, they elevate the 1st and 2nd ribs during forced inspiration. Unilaterally, they flex the neck to the ipsilateral side. The anterior and middle scalene are attached to the 1st rib, while the posterior scalene inserts at the 2nd rib,
What is the scalene triangle?
A triangle between the anterior and middle scalene muscles. The base is the first rib. The triangle contains the roots and trunks of the brachial plexus and subclavian artery.
What is Thoracic Outlet Syndrome?
Poor circulation of the hand and parathesia (tingling) along the medial portion of the hand. This is caused when the artery and lower portion of the brachial plexus get compressed within the scalene triangle by tight muscles, the presence of a cervical rib, a tumor, or inflammation.
What are the prevertebral muscles?
longus coli (superior oblique, inferior oblique, and vertical portion), longus capitis, rectus capitis anterior, and rectus capitis lateralis
What is the primary action of the rectus capitis lateralis?
to stabilize the skull on C1
Where is the best place to feel the pulse of the subclavian artery?
The greater supraclavicular fossa, within the posterior triangle of the neck just superior to the clavicle.
Where is the best place to feel the pulse of the common carotid artery?
Push aside the sternocleidomastoid and press lightly against transverse processes of cervical vertebrae
What does the external carotid artery supply? The internal?
External supplies the face and scalp, internal supplies the brain.
What is the aorta?
The aorta is the largest artery in the body. It arises from the left ventricle of the heart and is divided into 3 segments: 1) ascending– upward from the right ventricle. The right and left coronary arteries are branches to this portion of the aorta. The arch of the aorta is a continuation of the ascending aorta. It commences at T4, arches in the thorax to return to T4 posteriorly.
What branches off of the aortic arch?
the brachiocephalic trunk (arising from the right side of the arch and ascending into the neck). The trunk divides into the right common carotid and right subclavian, and the left common carotid and left subclavian.
At what level do the common carotid arteries divide?
C4 (upper border of the thyroid cartilage)
What does the subclavian artery supply?
the lower neck and upper limb
What does the vertebral artery supply?
the cervical spinal cord and brain
What are the boundaries for the vertebral artery?
anterior scalene laterally, longus coli medially, subclavian artery at its base, and the transverse process of C6 (carotid tubercle) at the apex.
What forms the brachiocephalic veins?
the union of the internal jugular and subclavian veins. The origin of these veins lies directly posterior to the sternoclavicular joints. The left vein crosses directly posterior to the manubrium to join the right brachiocephalic vein to form the superior vena cava.
which of the infrahyoid muscles are part of the superficial plane? the deep plane?
superficial plane = sternohyoid and omohyoid; deep plane = sternothyroid and thyrohyoid
Which muscle limits superior expansion of an enlarged thyroid gland?
sternothyroid
which muscle looks like a continuation of the sternothyroid?
thyrohyoid
What is the major venous channel draining the upper limb?
the subclavian vein
What does the occipital artery branch off of and what does it supply?
branches off of the external carotid artery and supplies the posterior half of the scalp
What does the subclavian artery do?
supply blood to upper limb
Where does the posterior auricular artery branch off and what does it do?
It branches off of the external carotid artery and contributes to the blood supply of adjacent muscles, parotid gland, facial nerve, and structures in the temporal bone, auricle, and scalp.
What does the superior thyroid artery do and where does it branch off?
Most inferior of the three anterior branches of the external carotid, runs to the thyroid gland. Supplies thyroid gland and gives off branches to the infrahyoid and SCM , and gives rise to the ascending laryngeal (which supplies larynx)
Where does the lingual artery branch off and what does it do?
arises from external carotid. gives dorsal lingual arteries to the posterior tongue and then bifurcates into the deep lingual and sublingual.
What does the internal jugular vein do?
drains blood from the brain, anterior face, cervical viscera, and deep muscles of the neck. The IJV leaves the cervical region by passing deep to the SCM
What comprises the brachiocephalic vein?
The IJV and the subclavian
What is the significance of the inferior bulb of the IJV?
the bulb has a bicuspid valve that permits blood to flow toward the heart while preventing backflow into the vein
The right subclavian artery arises from the ____, while the left subclavian artery arises from the______
the right subclavian artery arises from the brachiocephalic trunk, while the left subclavian artery arises from the arch of the aorta
When does the subclavian artery turn into the axillary artery?
the first rib
What are the branches of the subclavian artery?
vertebral artery, internal thoracic artery, and thyrocervical trunk from the first part of the subclavian; the costocervical trunk from the second part of the subclavian, and the dorsal scapular artery from the third part of the subclavian.
What does the thyrocervical trunk do?
2 lateral branches– the suprascapular artery, which supplies the muscles on the posterior scapula, and the cervicodosal trunk.
What does the thyroid gland do?
thyroid gland produces thyroid hormone, which controls the rate of metabolism and calcitonin, which controls calcium metabolism. it is located at C5-T1 vertebrae. blood supply is provided by inferior and superior thyroid arteries.
Where are the nerves of the thyroid gland derived from?
the cervical sympathetic ganglia
What is the larynx?
complex organ of voice production that lies in the anterior part of the neck at the level of C3-C6. If connects the inferior part of the pharynx to the trachea. Its most vital function is to protect the airway passage, especially during swallowing, when it serves as a sphincter of the lower respiratory tract.
Where do the inferior horns of the thyroid cartilages articulate with the lateral surfaces of the cricoid cartilages?
the cricothyroid joints. the main movement at these synovial joints are rotation and gliding of the thyroid cartilage, which results in changes of the length and tension of the vocal folds.
which is stronger, the thyroid or cricoid cartilage?
cricoid
which is larger, the thyroid or cricoid cartilage?
thyroid
what are the vocal folds?
source of sounds (tone) that come from the larynx. the vocal folds produce audible vibrations when their free margins are closes apposed during phonation and air is forcibly expired intermittently. they also serve as main inspiratory sphincter of the larynx when they are tightly closed. complete adduction of folds forms sphincter that prevents air entry.
