Dissection Notecards Flashcards
The external jugular vein is formed by the joining of the
Posterior division of the retromandibular vein and the posterior auricular vein
What vein passes deep to the SCM muscle to join the external jugular vein in the root of the neck
Anterior jugular vein
Boundaries of the posterior triangle of the neck
Anterior- posterior border of the sternocleidomastoid muscle
Posterior- anterior brother of the trapezius
Inferior- middle 1/3 of the clavicle
Superior roof- deep cervical fascia
Deep- muscles of the neck
The platysma muscle is innervated by
The cervical branch of the facial nerve
The external jugular vein drains into the
Subclavian vein
Nerves of the posterior triangle of the neck
Great auricular nerve- skin to the lower part of the ear to the angle of the mandible to the mastoid process
Lesser occipital nerve- scalp immediately behind the ear
Transverse cervical nerve- skin of anterior triangle of neck
Supraclavicular nerve- pass inferiorly to innervate the skin of the shoulder
Accessory nerve- innervates the SCM and the trapezius. Branches of spinal nerves C3-C4 join the accessory nerve in the posterior cervical triangle and these branches provide proprioceptive sensory innervation
Diaphragmatic pain referred to the shoulder
The supraclavicular nerves and the phrenic nerve (supplying the diaphragm) share a common origin from spinal cord segments C3 and C4. Irritation of the diaphragmatic parental pleura or parietal peritoneum covering the diaphragm (from an enlarged gall bladder) produces pain that is carried by the phrenic nerve and referred to the area supplied by the supraclavicular nerves (shoulder)
What is contained within the carotid sheath
Common carotid artery (internal carotid at more superior levels), internal jugular vein, and vagus nerve
The anterior triangle is subdivided by what muscles
Dig Astrid and omohyoid muscles
Contents of the muscular triangle
Boundaries
Infrahyoid muscle, thyroid gland, parathyroid glands
Superior belly of the omohyoid
Anterior border of the SCM
Median plane of the neck
Sternohyoid muscle function
Depresses the hyoid bone
Omohyoid bellies attachments and function
Superior belly is attached to the hyoid bone and the inferior belly is attached to the superior border of the scapula near the suprascapular notch
Depresses the hyoid bone
Sternothyroid muscle- superior attachment and function
Oblique line of the thyroid cartilage
Depresses the larynx
Thyrohyoid muscle inferior attachment and function
Oblique line of the thyroid cartilage
Elevates the larynx
The ansa cervicalis innervates 3 out of the 4 infrahyoid muscles
Sternohyoid, omohyoid, sternothyroid.
Contents of the submandibular triangle and borders
Submandibular gland, facial artery, facial vein, stylohyoid muscle, part of the hypoglossal nerve and lymph nodes
Digastric muscle bellies- anterior and posterior
Inferior border of the mandible
Deep/floor- mylohyoid muscle and hypoglossus muscle
A portion of the submandibular gland extends deep to the posterior surface of what
The mylohyoid muscle
Artery and vein associated with the submandibular gland
The facial vein passes superficial the the gland and the facial artery courses deep to the gland
Digastric muscle- attachment, innervation, and function
The anterior belly is innervated by the mylohyoid nerve, a branch of the mandibular division of the trigeminal nerve.
The posterior belly is innervated by the facial nerve and attaches to the mastoid process
The two bellies attach to each other by the intermediate tendon of the digastric muscle. The tendon is attached to the body and the greater horn of the hyoid bone by a fibrous sling.
Elevates the hyoid bone and depresses the mandible
What straddles the intermediate tendon of the digastric muscle
The stylohyoid muscle tendon- attaches to the body of the hyoid by doing so
The stylohyoid muscle is innervated by and function
Facial nerve
Elevates the hyoid bone
Submental triangle boundaries
Unpaired triangle that crosses the midline- only has lymph nodes in it
Anterior bellies of the left and right digastric muscles
Inferior hyoid bone
Floor- mylohyoid muscle
The mylohyoid muscle attachment
Mylohyoid line of the mandible and hyoid bone and the mylohyoid raphe
Supports the floor of the oral cavity
Contents of the carotid triangle
Boundaries
Common, internal and external carotid arteries, part of the hypoglossal nerve, and branches of the vagus nerve
Superior belly of the omohyoid, anterior border of the SCM, posterior belly of the digastric muscle
The hypoglossal nerve carries axons of
Spinal nerve C1 that branch off as the nerve to the thyrohyoid muscle
The superior root of the ansa cervicalis travels with
The hypoglossal nerve.
Composed mainly of C1 fibers
The inferior root of the ansa cervicalis (C2, C3) passes around the carotid sheath to join the superior root to form a loop
What nerve passes through the thyrohyoid membrane
Internal branch of the superior laryngeal nerve- supplies sensory fibers to the mucosa of the larynx
The internal branch of the superior laryngeal nerve joins
The external branch of the superior laryngeal nerve to form the superior laryngeal nerve
The external branch of the superior laryngeal nerve supplies the cricothyroid muscle and part of the inferior pharyngeal constrictor muscle
The carotid sheath contains
The common carotid, the internal carotid, the internal jugular vein, and the vagus nerve
Largest tributaries of the internal jugular vein
Lateral to the common carotid artery in the carotid sheath
Common facial, superior thyroid, and middle thyroid vein
Origin of the external carotid artery
Superior border of the thyroid cartilage
Passes on the medial side of and deep to the posterior belly of the digastric muscle
6 branches of the external carotid in the carotid triangle
Superior thyroid artery- level of the superior horn of the thyroid cartilage. Descends to the superior lobe of the thyroid gland. Branches to the superior laryngeal artery, which pierces the thyrohyoid membrane with the superior laryngeal nerve.
Lingual artery- leave of the greater horn of the hyoid bone, passes deeply to the muscles of the tongue
Facial artery- immediately superior to the lingual artery.
Has branches of occipital, posterior auricular, and ascending pharyngeal arteries.
At the bifurcation of the common carotid artery is the
Carotid sinus, a dilation of the origin of the internal carotid.
The wall of the carotid sinus contains pressoreceptors that monitor blood pressure. Innervated by glossopharyngeal and the vagus nerve
The carotid body
Small mass of tissue located on the medial aspect of the carotid bifurcation. Monitors changes in oxygen and CO2 concentration in the blood. Innervated by the glossopharyngeal nerve and the vagus
What vertebral levels are the thyroid gland located
C5-T1
The right and left inferior thyroid veins drain into
The right and left brachiocephalic veins
The thyroidea ima artery
Enter the thyroid gland from inferiorly, near the midline
Rare, clinically significant variant
What nerve passes immediately posterior to the lobe of the thyroid gland in the groove between the trachea and esophagus
Recurrent laryngeal nerve
Thyroid tumor or thyroidectomy in the clinic
The recurrent laryngeal nerve can be injured and paralysis of the laryngeal muscles will occur on the affected side. The result is hoarseness of the voice.
Parathyroid glands may be damaged or removed- at least one must be retained during a surgery
The subclavian vein lies and is joined by
Lies anterior to the anterior scalene muscle
Joined medially by the internal jugular to form the brachiocephalic vein
The thoracic ducts drain into the
Subclavian and internal jugular veins
The right subclavian artery is a branch of
The left subclavian artery is a branch of
The subclavian lie between
Brachiocephalic trunk
Aortic arch
The anterior and middle scalene muscles with the supraclavicular parts of the brachial plexus
3 parts of the subclavian artery
1- from its origin to the medial border of the anterior scalene muscle
2- posterior to the anterior scalene muscle
3- between the lateral border of the anterior scalene and lateral border of the first rib
The branches of the first part of the subclavian artery
Internal thoracic artery- passes inferiorly to supply the anterior thoracic wall
Thyrocervical trunk- anteriosuperior surface. Has 3 branches.
Vertebral artery- superiorly between the anterior scalene and longus colli muscle. Superiorly into the transverse foramen of vertebra C6
3 branches of the thyrocervical trunk
Transverse cervical artery- supplies trapezius
Suprascapular artery- to the suprascapular notch, superior to the transverse scapular ligament and supplies the spinatus muscles
Inferior thyroid artery- medially towards the thyroid gland. Gives off the ascending cervical artery.
The second parent of the subclavian artery branch
Costocervical trunk- divides into the deep cervical artery and the supreme intercostal artery, which give rise to posterior intercostal arteries 1 and 2.
The third part of the subclavian artery branch
Dorsal scapular artery- between the superior and middle trunks of the supraclavicular part of the brachial plexus to supply scapular region
Can also arise from the thyrocervical trunk
The recurrent laryngeal nerve is a branch of what nerve
The vagus
What nerve passes vertically down the anterior surface of the anterior scalene muscle posterior to the transverse cervical and suprascapular arteries
Phrenic nerve
The anterior and middle scalene muscles attach to
Clinically Relevant triangle
The first rib. These 3 make up the interscalene triangle
The subclavian artery and roots of the brachial plexus pass between the anterior and middle scalene muscles through this triangle. When there are additional muscular slips, an accessory cervical rib, or exostosis on the first rib, the triangle can be narrowed, causing the subclavian artery and/or roots of the brachial plexus to be compressed, resulting in ischemia or nerve dysfunction in upper limb
The lingula is the attachment for the
Sphenomandibular ligament
Mandibular foramen houses
The inferior alveolar nerve, artery and vein
Boundaries of the infratemporal fossa
Zygomatic arch and infratemporal crest of the sphenoid bone
Ramus of the mandible laterally
The infratemporal surface of the maxilla anteriorly
Lateral plate of the ptyergoid process medially
Great wing of the sphenoid - roof
The masseter muscle
Inferior border of the zygomatic arch and the lateral surface of the ramus of the mandible
Elevates the mandible to close the jaw and protrudes it. Innervated by the masseter is branch of the mandibular division of trigeminal nerve
The inferior attachment of the temporalis muscle
Fibers of the temporalis
Coronoid process of the mandible
Anterior portion- vertical fibers that elevate the mandible
Posterior portion- horizontal fibers that allow retrusion of the mandible
Deep temporal nerves
Branches of the mandibular division of the trigeminal
2 heads of the lateral pterygoid muscle
Anterior attachment of the superior head- infratemporal surface of the greater wing of the sphenoid
Anterior attachment of the inferior head- lateral plate of the pterygoid process
Posterior attachment are the temporomandibular joint and neck of mandible
Depresses and protrudes the mandible (opens jaw)
Inferior to the lateral pterygoid muscle vascular bundle
Run
Inferior alveolar nerve, artery, and vein
Run through the mandibular foramen and pass distally into the mandibular canal
What nerve arises from the inferior alveolar nerve
The mylohyoid nerve- just before it enters the mandibular foramen and runs in the mylohyoid groove
Mental nerve- through mental foramen to innervate the chin and lower lip
The inferior alveolar nerve provides
Sensory info to the mandibular teeth
Nerve located anteriorly to the inferior alveolar nerve
Lingual nerve- passes medial to the third mandibular molar and innervates the mucosa of the anterior two thirds of the tongue and floor of oral cavity
The lingual and inferior alveolar nerve pass between
The inferior border of the lateral pterygoid muscle and the medial pterygoid muscle- used as guides to separate the two muscles
Medial pterygoid muscle
Proximal attach to the maxilla and the medial surface of the lateral plate of the pterygoid process
Distal attach to the inner surface of the ramus of the mandible
Elevates and protrudes the jaw (closes it)
The external carotid artery bifurcates into what two arteries in the infratemporal fossa
Maxillary and superficial temporal arteries
Branches of the maxillary artery
Middle meningeal artery- passes superiorly through a split in the auriculotemporal nerve through the foramen spinosum
Deep temporal arteries- deep surface of temporalis muscle
Masseteric artery- mandibular notch to deep masseter muscle
Inferior alveolar artery- mandibular foramen
Buccal artery- supply cheek
The maxillary artery courses toward-
Before disappearing it divides into four branches
Pterygomaxillary fissure
Posterior superior alveolar artery (enters the infratemporal surface of the maxilla- pterygopalantine fissure), infraorbital artery, descending palatine artery, sphenopalatine artery
