Anterior Triangle Flashcards
Pharyngeal Apparatus
Contributes to formation of head and neck (face, nose, mouth, larynx, pharynx and neck)
Pharyngeal Arches
6 arches
develop at lateral end of foregut (primordial pharynx) during 1st part of week 4
-Contain neural crest cells
-arches separated on external surface by PHARYNGEAL GROOVES and on the inside by PHARYNGEAL POUCHES
Mesenchyme of Arches
Contains:
- Blood vessel (artery) -Cartilage (forms skeletal part)
- Muscular component -Nerve
First Arch Bones, Muscles and Nerve
Mandibular Arch -MAXILLARY prominence=maxilla -MANDIBULAR prominence=mandible Muscles -mastication, mylohyoid, anterior belly of digastric, tensor tympani, tensor veli palatini Nerve=CN V
Second Arch Bones, Muscles and Nerve
Hyoid Arch=hyoid bone
Muscles= facial expression, stapedius, stylohyoid and posterior belly of digastric
Nerve=CN VII
Third Arch
contributes to formation of hyoid bone
Muscle=stylophayngeus muscle swallow
Nerve= CN IX
Fourth Arch
cartilages of larynx
Nerve=CN X vagus
Pharyngeal Membranes
ectoderm of grooves on outside of pharyngeal wall make contact with endoderm of pouches on inside to for these membranes
1st membrane=tympanic
-all other membranes disappear
Boundaries of Anterior Triangle
Anterior Midline of neck Inferior border of mandible Anterior border of SCM Apex is Jugular Notch Base=inferior border of mandible Roof=superficial fascia, platysma, skin
Submandibular Triangle (digastric)
BOUNDED by
Superiorly=inferior border of mandible
Laterally=posterior belly of digastric
Medially=anterior belly of digastric
FLOOR=mylohyoid and hyoglossal muscles
CONTENTS= submandibular gland, submandibular ganglion (parasymp), submandibular lymph nodes, CNXII (hypoglossal n), Facial a & v
Submental Triangle
BOUNDED by
Inferiorly-hyoid bone (base)
Laterally-anterior bellies of digastric
Floor- mylohyoid m, the two mylohyoid muscles join in the anterior midline of the neck by forming a raphae
CONTENTS=submental lymph nodes, beginning of anterior jugular veins
Carotid Triangle (most important)
BOUNDED by
Anteriorly-superior belly of omohyoid
Superiorly-posterior belly of digastric
Laterally-anterior border of SCM
CONTENTS= carotid sheath (base of neck-skull), tubular carotid sheath
Tubular Carotid Sheath
Vagus Nerve
Common Carotid and Internal Carotid Arteries
Internal Jugular Vein
-Once common carotid splits the internal carotid remains in sheath up to the skull
Muscular Triagle
BOUNDARIES
Anterior-anterior midline of neck
Laterally-superior belly of omohyoid m
Interiorly-anterior border of SCM
CONTENTS= Thyroid and parathyroid (C6) Infrahyoid muscles (strap)=sternothyroid, sternohyoid, thyrohyoid, omohyoid
Right Common Carotid
Branch of brachiocephalic trunk
Left Comon Carotid
Branch of Aorta
Carotid Occlusion
obstruct blood flow to brain and lead to stroke or transient ischemic attack
Carotid Sinus
Dilated intitial segment of internal carotid
-inervated by CN IX AND X=monitors arterial blood pressure
External Carotid Artery
Terminates in parotid by bifurcating=SUPERFICIAL TEMPORAL and MAXILLARY ARTERIES
Branches of External Carotid Artery
Traveling Superiorly Superior Thyroid Ascending Pharygeal Lingual Facial Occipital Posterior Auricular Maxillary Superficial Temporal
Right Subclavian Artery
originates from the brachiocephalic artery
-divided into 3 parts by the anterior scalene m
Left Subclavian Artery
directly from aorta
-divided into 3 parts by the anterior scalene m
1st Part of Subclavian Artery
Medial border of anterior scalene
Vertebral a
Internal thoracic a
Thyrocervical Trunk = transverse cervical a, suprascapular artery, inferior thyroid a
2nd Part of the Subclavian Artery
costocervical trunk
posterior to scalene (cant see)
3rd part of Subclavian Artery
Lateral border of anterior scalene to 1st rib
Dorsal scapular artery
Internal Jugular Vein
Begins outside skull on surface of jugular foramen as dilated structure=JUGULAR BULB
- Descend inferior to carotid sheath
- Joins subclavian vein and empties into brachiocephalic vein
Anterior Jugular Vein
Beginning=Submental triangle
-drains into external jugular vein
Vagus Nerve
Longest Cranial Nerve CN X -exits skull through jugular foramen Gives rise to the following branches -Recurrent Laryngeal -contributions to pharyngeal plexus -cardiac branches -Superior laryngeal
Ansa Cervicalis
Motor part of Cervical Plexus =C1-C3
Hypoglossal Nerve
CNXII
Sympathetic Trunk
Longitudinal strands of autonomic fibers beginning at C1
3 Ganglia of Cervical Component
1)Superior Cervical Ganglion=largest, C1 C2 level
2)Middle Cervical Ganglion= level of cricoid cartilage C6
3)Inferior Cervical Ganglion-somtimes fused with thoracic ganglion and is then know as Stellate Ganglion
located at level of C7-superior border of 1st rib
