Blood vessels, Nerves, viscera Flashcards
Where does the Right common carotid artery originate?
-brachiocephalic trunk
Where does the Left common carotid artery originate?
-aortic arch
where does the common carotid bifurcate?
-ascends through carotid sheath to thyroid cartilage to divide into external and internal carotid arteries
Carotid sheath
- internal jugular veins are lateral to common carotid
- vagas nerve lies between the internal jugular vein and the common carotid artery, posteriorly
carotid sinus
- localized dilation at terminal part of common carotid/ start of internal carotid artery
- walls contain glossopharyngeal nerve endings sensitive to changes in blood pressure
carotid body
- highly vascular epithelial structure at bifurcation of common carotid
- has nerve endings from glossophayngeal nerve to respond to chemical changes in blood
what are important in reflex control of heart rate, BP, respiratory rate and depth?
-carotid sinus and carotid body
External carotid artery
- begins at upper border of thyroid cartilage
- ascends into carotid triangle
- leave carotid triangle and runs deep to posterior belly of digastric and stylohyoid
- divides into superficial temporal artery and maxillary artery in parotid gland
AnteriorBranches of the external carotid artery
- superior thyroid
- lingual
- facial
Posterior branches of external carotid artery
-occipital and posterior auricular arteries
Medial branch of external carotid artery
-ascending pharyngeal artery
Terminal branch of external carotid artery
-superficial temporal and maxillary arteries
superior thyroid artery
- anterior branch of external carotid artery
- descends vertically to supply thyroid
- branches into superior laryngeal artey which travels with internal laryngeal nerve
Lingual artery
- anterior branch of external carotid(near hyoid bone)
- initial segment is crossed superficially by hypoglossal nerve
- passes deep to hypoglossal muscle
- gives off branches that supply tongue
facial artery
- ascends deep to posterior belly of digastric and stylohyoid and curves around mandible to enter the face
- BEFORE entering the face, gives branches that supply pharynx, soft palate, tonsils, submandibular gland
Occipital artery
- posterior branch of external carotid artery
- passes deep to posterior belly of digastric and mastoid process to get to the back of scalp
- terminal branches work with occipital nerve to supply back of scalp
- branches along the course supply auricle, middle ear,cranial dura mater
posterior auricular artery
- posterior branch of external carotid artery
- insertion: notch between cartilage of external acoustic meatus and mastoid process
- supplies auricle, middle ear, scalp above and behind the ear, and parotid gland
Ascending pharyngeal artery
- medial branch of the external carotid artery
- smallest branch of external carotid
- goes along pharyngeal wall parallel to internal carotid artery
- supplies to pharynx, soft palate, palantine tonsil, middle ear, and cranial dura mater
Superficial temporal artery
- terminal branch of external carotid
- upward continuation of external carotid
- terminates at root of zygomatic process of temporal bone
- divides into anterior and posterior branches
- supplies temporal, frontal, and parietal regions of the skull
- branches supply to external ear, parotid gland, face, and temporomandibular joint
Maxillary artery
- terminal branch of external carotid artery
- passes deep to neck of mandible
- runs through infrtemporal fossa and terminates in pterygopalatine fossa
- supplies external and middle ear, teeth, muscles for mastication, face, nasal cavity
Internal jugular vein
- drainage from most of head and neck
- starts at jugular foramen and ends in the sternoclavicular junction where it meets subclavian vein to make braciocephalic vein
- in carotid sheath, runs laterally from common carotid artery and internal carotid artery
- deep cervical lymph
- bulbs
bulbs of the internal jugular vein
- dilation on inferior and superior ends of the vein
- superior and inferior bulbs
Brachiocephalic vein
-formed by subclavian and internal jugular vein
internal jugular vein tributaries
- inferior petrosal and sigmoid sinuses drain into the superior bulb
- pharyngeal vein
- facial vein
- occipital vein
- superior and middle thyroid vein
- lingual vein
Right Subclavian artery
- branch of brachiocephalic trunk
- begins posterior to sternoclavicular joint
Left subclavian artery
-branch off the aortic arch
what divides the subclavian artery into 3 parts?
-scalenus anterior muscle
first part of subclavian artery
-from origin to medial border of scalenus anterior Branches -vertebral artery -thyrocervical -internal thoracic artery
second part of subclavian artery
-posterior to scalenus anterior
Branches:
-costocervical trunk(may originate from first part)
Third part of subclavian artery
- from lateral border of scalenus anterior to lateral border of the first rib
- becomes continuous with axillary artery
- gives rise to dorsal scapular artery or may have no branches
vertebral artery
- originates from first part of subclavian artery
- divided into 4 parts
first (prevertebral) part of vertebral artery
- run from subclavian artery to transverse foramen of C6
- between longus colli and scalenus anterior
- inferior cervical sympathetic ganglion lies posterior
Second (cervical) part of vertebral artery
- through transverse foramen of C6 to C1
- anterior to those ventral rami
- gives off small muscular and spinal branches
Third (atlantic) part of vertebral artery
- lies in a groove on superior surface of posterior arch of atlas
- within the suboocipital triangle
Fourth (intracranial) part of vertebral artery
- pierces dura mater and arachnoid and ascends into cranial cavity via foramen magnum
- gives off branches for blood supply to the brain stem
thyrocervical trunk branches
- inferior thyroid artery
- superficial(transverse) artery
- suprascapular artery
inferior thyroid artery
- branch of thyrocervical trunk
- supplies: larynx, trachea, pharynx, esophagus, thyroid and parathyroid glands
- closely related to the recurrent laryngeal nerve
- branches into ascending cervical artery: supplies adjacent muscles
superficial (transverse) artery
- branch of thyrocervical trunk
- supplies superficial muscles of the upper back
- when dorsal scapular artery comes off of subclavian artery, it is called superficial
- when it branches to form the dorsal suprascapular, it is called transverse
suprascaular artery
- branch of thyrocervical trunk
- joined by suprascapular nerve as it approaches scapula
- supplies muscles on posterior aspect of scapula
Costocervical trunk
- originates from the second part of the subclavian artery
- goes posterior over cervical pleura toward the first rib where it splits into two branches
What are the branches that costocervical trunk divides into?
- supreme intercostal artery
- deep cervical artery
Supreme intercostal artery
- branch of costocervical trunk
- descends in front of neck of first and second ribs
- gives off posterior intercostal arteries of upper 2
Deep cervical artery
- branch of costocervical trunk
- passes between transverse process of C7 and neck of first rib
- then goes between semispinalis capitis and semispinalis cervicis muscle
- anastomoses with occipital artery
- supplies deep muscles of back and neck
Dorsal scapular artery
- may originate from transverse cervical artery or MOST COMMONLY from third part of subclavian artery
- runs through brachial plexus, deep to levator scapula to the angle of the scapula
- goes along medial surface of scapula with dorsal scapular nerve
- anastomoses with suprascapular and subscapular arteries
Subclavian vein
- begins at lateral border of first rib, continuation of axillary vein
- separated from subclavian artery by scalenus anterior muscle
- joins internal jugular vein posterior to sternoclavicular joint to form brachiocephalic vein
- EXTERNAL JUGULAR VEIN IS ONLY TRIBUTARY
Vagas Nerve
- motor and sensory fibers
- originates at medulla oblongata and exits skull at jugular foramen
- descends in neck within carotid sheath
What structures does the vagas nerve pass between?
Superiorly: internal jugular vein and internal carotid artery
Inferiorly: internal jugular vein and common carotid artery
What sensory ganglia are associated with the vagas nerve?
Superior ganglion: small, lies on vagas nerve within jugular foramen
Inferior ganglion: larger, lies on vagas nerve inferior to jugular foramen
Branches of vagas nerve within the jugular foramen
Meningeal branch: supplies dura mater of posterior cranial fossa
Auricular branch: runs with temporal bone-supplies to auricle, external acoustic meatus, and tympanic membrane
Name the branches of the vagas nerve in the neck
- pharyngeal branch
- superior laryngeal nerve
- cardiac branches
- right recurrent laryngeal nerve
Pharyngeal branch of vagas nerve
- motor innervation for muscles of pharynx and soft palate
- part of the pharyngeal plexus
name the branches of superior laryngeal nerve
- internal laryngeal nerve
- external laryngeal nerve
internal laryngeal nerve
- pierces thyrohyoid membrane with superior laryngeal vessels
- supplies SENSORY innervation to mucosa of laryngopharynx, larynx, and posterior part of tongue
External laryngeal nerve
-MOTOR innervation for cricothyroid muscle and inferior pharyngeal constrictor muscle
Cardiac branches of vagas nerve
-end in cardiac plexus in thorax
Right recurrent laryngeal nerve
- branch of vagas nerve
- curves around inferior aspect of right subclavian artery
- ascends to larynx in groove between trachea and esophagus to the right side
Accessory Nerve
- motor fibers (union of spinal and cranial roots)
- originates from C1 to C5 segments of spinal cord
- enters posterior cranial fossa through foramen magnum
- exits cranial fossa through jugular foramen
- supplies sternocleidomastoid and trapezius
Hypoglossal nerve
- MOTOR fibers that supply the tongue
- originates in medulla and exits skull by hypoglossal canal
- joined by fibers from ventral rami of C1 and they can go to ansa cervicalis or stay on to supply geniohyoid
Name the branches of the hypoglossal nerve
- meningeal branch
- upper root of ansa cervicalis
- nerves to thyrohyoid and geniohyoid
- terminal branches that supply intrinsic and extrinsic muscles of the tongue-only branch with true hypoglossal fibers
cervical part of the sympathetic trunk
- upward continuation of thoracic sympathetic trunk
- NO WHITE COMMUNICATING RAMI
- go through sympathetic trunk to get to cervical ganglia
- divides into 3 interconnected ganglia
- ALL BRNACHES FROM THESE ONLY HAVE POSTGANGLIONIC FIBERS
Superior cervical ganglion
-largest cervical ganglion Branches: -internal carotid nerve -external carotid nerve -grey communicating rami(C1-C4) -pharyngeal branches -superior cervical cardiac nerve
Middle Cervical ganglion
-smalles and most variable cervical ganglion
-lies at level of cricoid cartilage, close to inferior thyroid artery
Branches
-grey rami(C5 and C6)
-Middle cervical cardiac nerve
-thyroid branches
Inferior cervical ganglion
-can fuse with first throacic ganglion to form CERVICOTHORACIC (STELLATE) GANGLION
-lies between transverse process of C7 and neck of first rib
Branches
-grey rami(C7 and C8)
-branches that go with vertebral and subclavian arteries
-inferior cervical cardiac ganglion
-ansa subclavia
Cervical plexus
- formed by ventral rami of C1 to C4 spinal nerves
- rami connected by nerve loop located anterior to levator scapulae and deep to sternocleidomastoid
Cutaneous branches of cervical plexus
-lesser occipital, greater auricular, transverse cervical, and supraclavicular nerves
Branches of cervical plexus
- cutaneous branches
- ansa cervicalis
- phrenic
- muscular branches
Phrenic nerve off cervical plexus
- anterior to scalenus anterior
- anterior to first part of subclavian artery
- through mediastinum to reach diaphragm
Muscular branches of cervical plexus
-sensory fibers to trapezius and sternocleidomastoid
what does thyroid gland secrete?
- endocrine gland
- secretes: thyroxine(T4) and triiodothyronine(T3) to stimulate metabolic rate
- also secretes calcitonin to lower calcium levels
What is the thyroid surrounded by?
- connective tissue sheath from PRETRACHEAL LAYER of deep cervical fascia
- moves it up and down when swallowing
Thyroid gland location
- originates from endoderm of floor of pharynx
- migrates inferiorly for final position
- foramen cecum indicates origin
thyroglossal duct
-connects thyroid to tongue through migration
Thyroglossal cysts
- caused by persistence of a segment of thyroglossal duct
- usually anterior midline of the neck near hyoid bone
Name the lobes of the thyroid
- right and left lobe
- isthmus
- pyramidal lobe
Right and left lobe of thyroid
Apex-directed upward and reaches oblique line of thyroid cartilage
Base-directed downward and reaches 4 or 5th tracheal cartilages
Isthmus
-extends across midline anterior to second and third tracheal cartilages
Pyramidal lobe
- projects upward from isthmus
- not always there
- represents remnant of thyroglossal duct
Relations to lobes
Anterolaterally-sternohyoid, sternothyroid, sternocleidomastoid
Posterolaterally- carotid sheath and contents
Medially- larynx, trachea, pharynx, esophagus, laryngeal nerves
Posterior border-parathyroid glands
Relations to isthmus
Anteriorly: sternohyoid, sternothyroid, anterior jugular vein
Posteriorly: 2nd and 3rd tracheal cartilages
Name the two PRIMARY arteries associated with the thyroid
- superior thyroid artery
- inferior thyroid artery
What artery is associated with the thyroid in 10% of people
Thyroid ima artery
- originates from brachiocephalic trunk of aortic arch
- anterior surface of thyroid to reach isthmus
- think about this when youre a surgeon
Thyroid veins
- superior and middle thyroid veins-drain into internal jugular vein
- inferior thyroid vein-drain into brachiocephalic vein
parathyroid glands
2 superior and 2 inferior
- under thyroid facial sheath
- secrete parathormone(increase calcium levels)
- artery supply: superior and inferior thyroid arteries
- Veins: drain into thyroid venous plexus
superior parathyroid glands
-lie at lower border of cricoid cartillage
Inferior parathyroid glands
- lie near inferior poles of lobes of thyroid
- less consistant in position
- can go below thyroid gland or up towards thymus
