1. Triangles Of Neck And Larynx Flashcards
What is at the vertebral level of C3-C4?
- Body of hyoid bone
- Upper margin of thyroid cartilage
- Bifurcation of common carotid artery
What is at the vertebral level of C5-C6?
- Arch of cricoid cartilage
- Superior end of esophagus
- Superior end of trachea
Boundaries of anterior triangle
- Midline of neck
- SCM
- Lower border of mandible
Boundaries of posterior triangle
- SCM
- Trapezius m.
- Clavicle
Submandibular triangle
- Anterior belly of digastric
- Posterior belly of digastric
- Inferior border of mandible
Boundaries of submental triangle
- Midline of neck
- Anterior body of digastric m.
- Body of hyoid
Boundaries of muscular triangle
- Body of hyoid
- Superior belly of omohyoid
- SCM
Boundaries of carotid triangle
- Posterior belly of digastric m.
- Superior belly of omohyoid m.
- SCM
Contents of the floor of the posterior triangle
- Splenius capitis m.
- Levator scapulae m.
- Scalene mm. (posterior, middle, anterior)
Arteries in the posterior triangle (most important)
- thyrocervical trunk
- transverse cervical a.
- deep cervical a. (II)/dorsal scapular a.(III)
- superficial cervical a.
- suprascapular a.
- transverse cervical a.
Veins in the posterior triangle
- External jugular vein (EJV)
- Subclavian vein (SV)
Nerves in the posterior triangle
- Cervical plexus (cutaneous branches)
- Lesser occipital n.
- Greater auricular n.
- Transverse cervical n.
- Supraclavicular n.
- Ansa cervicalis
- Spinal accessory n.
- Phrenic n.
- Roots of the brachial plexus
- Contraction or shortening of SCM causes head to tilt ____ and face to tilt _____ affected side.
- What is this called?
- Head tilts toward; face tilts away
- Torticollis
Muscles of the anterior triangle
- Suprahyoid muscles (elevate hyoid and larynx)
- Mylohyoid m.
- Stylohyoid m.
- Digastric m. (anterior & posterior bellies)
- Geniohyoid
- Infrahyoid muscles (depress hyoid & larynx)
- Sternohyoid
- Omohyoid
- Sternothryoid
- Thyrohyoid
Arteries of the anterior triangle
From the external carotid artery:
- superior thyroid a
- lingual a.
- facial a.
- ascending pharyngeal a.
- occipital a.
- posterior auricular a.
- maxillary a.
- superifical temporal a.
Triangles within the anterior triangle
- Submandibular
- Submental
- Carotid
- Muscular (omotracheal)
What are the contents of the submandibular triangle?
- Submandibular gland
- Submandicular lymph nodes
- Hypoglossal nerve (CN XII)
- Nerve to myolohyoid m.
- Facial artery and vein
What are the contents of the submental triangle?
- Submental lymph nodes
- Small veins that unite to form anterior jugular vein
What are the contents of the carotid triangle?
- Carotid sheath: CCA, ICA, IJV, vagus n, deep cervical LN, carotid sinus n., sympathetic nerve fibers
-
Not within the carotid sheath:
- Arteries: branches of the ECA
- Nerves: internal and external laryngeal nerves, hypoglossal nerve, spinal accessory nerve, ansa cervicalis
What are the contents of the muscular triangle?
- Muscles: sternohyoid m., sternothyroid m., thryohyoid m.
- Viscera: thyroid gland, parathyroid glands, larynx, trachea, esophagus
- Arteries: common carotid a., superior thyroid a., inferior thyroid a.
- Veins: anterior jugular v., thyroid v. (superior, middle, inferior)
- Nerves: ansa cervicalis, external laryngeal v., recurrent laryngeal v.
Vasculature of the carotid triangle
External carotid a.
- Ascending pharyngeal a.
- Occipital a.
- Posterior auricular a.
- Superior thyroid a.
- Lingual a.
- Facial a.
Which structure is an important baroreceptor (arterial BP)?
carotid sinus
What structure is an important chemoreceptor (O2 levels in blood)?
carotid body
sole motor supply to the diaphragm
phrenic n.
clinical importance of the phrenic n.
- sole motor supply to diaphragm => phrenic n. must be identified during thoracic surgery and preserved
- phrenic n. arises from neck => pt w/ spinal cord injuries below neck are still able to breathe effectively despite paralysis of lower limbs
Where is the phrenic n.?
superficial to the anterior scalene m.
cervical plexus
anterior rami of C1-C4
thin connective tissue layer that lies between dermis and investing layer of deep cervical fascia
subcutaneous layer (superficial fascia)
contents of the superficial fascia
- cutaneous nerves
- blood and lymphatic vessels
- superficial lymph nodes
- fat
- platysma m.
(1) muscle of facial expression
(2) innervation of this muscle
(1) platysma m.
(2) Facial N. (CN VII)
layers of the deep cervical fascia
- investing layer
- pretracheal layer
- prevertebral layer
- most superficial of the 3 deep cervical fascial layers
- surrounds entire neck
- encloses sternocleidomastoid and trapezius m.
- encloses parotid and submandibular glands
- extends to manubrium, clavicles, acromion, spines of scapula
deep cervical fascia
- located in the anterior region of the neck
- blends with fibrous pericardium of the heart
- muscular layer (infrahyoid muscles), buccopharyngeal fascia, and a visceral layer
pre-tracheal layer
- encloses the vertebral column and associate muscles
- extends laterally as the axillary sheath into the arm
- extends from cranial base to mediastinum
pre-vertebral layer