Course Hero Logo

At the level of the superior border of the thyroid

Course Hero uses AI to attempt to automatically extract content from documents to surface to you and others so you can study better, e.g., in search results, to enrich docs, and more. This preview shows page 31 - 34 out of 50 pages.

at the level of the superior border of the thyroid cartilage, it divides into the internal andexternal carotid arteriesCarotid sinus1.is a slight dilation of the proximal part of the internal carotid artery, which may involve thecommon carotid artery2.innervated principally by the glossopharyngeal nerve ( cranial nerve IX ) through thecarotid sinus nerve as well as by the vagus nerve ( cranial nerve X )3.it is a baroreceptor ( pressoreceptor ) that reacts to changes in arterial blood pressureCarotid body1.is a small, reddish brown ovaid mass of tissue in life2.it lies on the medial ( deep ) side of the bifurcation of the common carotid artery, in closerelation to carotid sinus3.supplied mainly by the carotid sinus nerve (9thand 10th) glossopharyngeal and vagusnerves4.it is a chemoreceptor that monitors the level of oxygen in the blood5.it is stimulated by low levels of oxygen and initiates a reflex that increases the rate and depth
32of respiration, cardiac rate and blood pressureCarotid sheath1.is formed by the extensions of all three layers of deep cervical fascia ( investing,pretracheal and prevertebral ) that fuse together2.surrounds the neurovascular structuresa)common carotid arteryand internal carotid artery ( medially )b)internal jugular vain( laterally )c)vagus nerve( posteriorly )d)ansa cervicalis ( lies on the anterolateral aspect of the sheath )e)deep cervical lymph nodes ( lie along the carotid sheath and internal jugular vein )Muscular triangleBoundariesAbove and laterally by the superior belly of omohyoidBelow and laterally by the anterior border of SCMMedialy by the median plane of the neckContents of the muscular triangle1.infrahyoid muscles ( sternohyoid, sternothyroid and thyrohyoid)2.viscera of the neck ( thyroid and parathyroid glands )Muscles in Anterior Cervical RegionThe hyoid muscles steady or move the hyoid and larynxSuprahyoid musclesare superior to the hyoid and connect it to the cranium1.mylohyoid2.geniohyoid3.stylohyoid4.digastric- anterior and posterior belliesInfrahyoid musclesare inferior to hyoid1.of ten called strap muscles because of their ribbon - like appearance2.these four muscles anchor the hyoid, sternum, clavicle and scapula and depress the hyoid andlarynx during swallowing and speaking3.they are arranged in two planes, superficial and deepSuperficial plane1.sternohyoid2.omohyoid - superior and inferior belliesDeep plane1.sternothyroid2.thyrohyoidSuprahyoid musclesMylohyoidforms the mobile and stable floor of the mouthOrigin from the mylohyoid line of mandible
33Insertion into the mylohyoid raphe and body of hyoidNerve supply by the mylohyoid nerve, branch of inferior alveolar nerve from mandibular|nerve ( branch of trigeminal nerve - 5thcranial nerve )Action is to elevate the hyoid, floor of mouth and tongue during swallowing and speakingGeniohyoidlies superior to mylohyoid muscleOrigin from the inferior mental spine of mandibleInsertion into the body of hyoid boneNerve supply by C1 fibers via hypoglossal nerve( 12thcranial nerve )Actions1.

Upload your study docs or become a

Course Hero member to access this document

Upload your study docs or become a

Course Hero member to access this document

End of preview. Want to read all 50 pages?

Upload your study docs or become a

Course Hero member to access this document

Term
Winter
Professor
RonaldG.Mayne
Tags
oculomotor nerve, Veins of the head and neck, Cavernous sinus

Newly uploaded documents

Show More

Newly uploaded documents

Show More

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture