Anterior triangle of the neck Flashcards
what divides the anterior from the posterior triangle
sternocleidomastoid (SCM) - anterior boundary of posterior triangle and vice versa
what is the cranial boundary of the anterior cervical region
mandible
what is the caudal border of the anterior triangle
sternum, jugular notch
what is the lateral border of the anterior cervical region
SMC
what are the 4 divisions of the anterior triangle
submental
submandibular
cartoid
muscular/omotracheal
what is found in the submental division of the anterior triangle
submental lymph nodes (drain the anterior part of tongue)
submental arteries and veins
mylohyoid nerve
beginning of anterior jugular vein?
what is the in submandibular division of the anterior triangle
lingual nerve, submandibular ganglion
submandibular salivary gland, lymph nodes
facial artery and vein
lingual artery and vein
hypoglassal nerve
what is in the carotid division of the anterior triangle
inside carotid sheath:
-common carotid artery (medially), continues as internal carotid artery from c4 upward)
-internal jugular vein (laterally)
-superior toot of deep ansa cervicalis
-vagus nerve
outside carotid sheath:
-branches of external carotid artery: superior thyroid (runs caudally to omotracheal triangle, lingual (runs cranially to submandibular triangle), facial (runs cranially to submandibular triangle)
-arch of hypoglossal nerve, sympathetic trunk and superior cervial ganglion, accessory nerve
- veins: facial, retromandibular, lingual, superior thyroid
-lateral group of deep cervial lymph nodes
what is the muscular division of the anterior triangle
sternohyoid and sternothyroid form the floor beneath which lies the thyroid gland, layrnx, trachea and oesophagus
what are the divisions of the fascial layers of the neck
superficial cervical fascia - lies close to skin
deep fascia (investing layer, pretracheal layer, prevertebral layer, alar fascia and carotid sheath)
what is the first structure that is revealed when you remove the skin of the neck
platysma
what are the attachments of platysma
from fascia above pectoralis major and clavicle to the lateral neck and onto mandible
what is the innervation of platysma
facial nerve CN VII
platysma forms a thin layer than covers what surfaces of the neck
anterior and lateral
what is the function of platysma
considered a muscle of facial expression even though it functions to tighten the skin of the neck
all the muscles of facial expression are innervated by what
facial nerve CN VII
how does platysma vary
varies in its exact attachment areas on the face and neck
what superficial vein of the neck crosses the anterior surface of sternocleidomastoid
external jugular vein
some individuals have what superficial vein of the neck
anterior jugular vein in the midline, may be absent
what usually joins with the external jugular vein
posterior division of the retromandibular vein
the posterior division of the retromandibular vein usually joints the external jugualr vein which carries blood where
down the neck into the subclavian vein
what vein is found posterior to sternocleidomastoid
internal jugular vein
the internal jugular vein is part of what triangle of the neck
anterior triangle
the external jugular vein is in what triangle of the neck
posterior triangle
what vein joins with the anterior division of the retromandibular vein
facial vein
the facial vein joins with the anterior division of the retromandibular vein and this usually drains where
internal jugular vein
where does the internal jugular vein lie in the neck
deeper in the neck within the carotid sheath
the internal jugular vein drains where
subclavian vein to form brachiocephalic vein
the anterior jugular veins can drain where
external or internal veins depending on the individual
what other venous structure may be seen in the neck
communicating vein between the facial and anterior jugular veins
the cervical plexus forms from what
anterior rami of C1-C4
the cervical plexus is joined into loops that lie anterior to what
levator scapulae and scalenus medius
what fascial layer covers the cervical plexus
covered by pre-vertebral layer of deep cervical fascia
what innervation does the cervical plexus carry
somatic motor and sensory (plus sympathetic)
what are the sensory branches of the cervical plexus
lesser occipital
greater auricular
transverse cervical
supraclavicular
what is the general direction of the lesser occipital sensory branch
behind the ear
what is the general direction of the greater auricular sensory branch
infront of the ear
what is the general direction of the transverse cervical branch
under the chin
what is the general direction of the supraclavicular sensory branch
down the neck/over clavicle
what is the name of the loop of nerves created by the cervical plexus
the ansa cervicalis
what fibres does the ansa cervicalis contain
C1 to C3
the ansa cervicalis sits where
anterior surface of the carotid sheath
what are the motor nerves coming from the cervical plexus
ansa cervicalis
to sternohyoid, sternothyroid and omohyoid
to thyrohyoid
to glenohyoid
to trapezius C3, 4 (proprioception)
to levator scapulae C3 4
to SCM C2 3 (proprioception)
Phrenic (C3 4 5)
what is meant by the term suprahyoid
between the hyoid bone and the skull or mandible
what is meant by the term infrahyoid
between the hyoid bone and the sternum or thyroid cartilage
the hyoid bone lies between what
mandible and larynx
what is the function of the supra-hyoid muscles
raise hyoid bone
mylohyoid and digastric also depress mandible
what are the suprahyoid muscles
mylohyoid digastric (anterior and posterior belly)
geniohyoid
stylohyoid
what nerve innervates the posterior belly of the digastric and stylohyoid
facial nerve
what nerve innervates the anterior belly of digastric and the mylohyoid
mandibular division of the trigeminal nerve CNV3
what is geniohyoid found
deep to mylohyoid
what innervates geniohyoid
C1 via hypoglossal nerve CN XII
where does the anterior belly of digastric attach
mandible and hyoid bone
where does the posterior belly of the digastric attach
mastoid process of temporal bone and hyoid bone
what does stylohyoid attach to
styloid process of temporal bone and hyoid
what does mylohyoid attach to
mylohyoid line of the mandible and to the hyoid bone
what muscle forms a diaphragm in the floor of the oral cavity
mylohyoid
what does geniohyoid attach to
inferior genial tubercle of the mandible and the hyoid bone
the facial nerve exits the skull via … so passes close to what
stylomastoid foramen
posterior belly of digastric and to stylohyoid
what supplies the muscles of mastication
mandibular division of the trigeminal nerve
what is another name for the infrahyoid muscles
strap muscles
what is the function of the infrahyoid/strap muscles
depress the hyoid bone and thyroid cartilage
what are the superficial infrahyoid/strap muscles
omohyoid
sternohyoid
what are the deeper infrahyoid/strap muscles
sternothyroid
thyrohyoid
what does thyroid hyoid of the infrahyoid/strap muscles attach to
thyroid cartilage and hyoid bone
(name indicates attachment)
what gives omohyoid its name
shape - superior and inferior belly passing through a sling
describe omohyoid
superior belly that attaches to the hyoid - this becomes tendinous near the clavicle and passes through a small fascial sling that is attached to the clavicle
inferior belly attaches to the scapula
what is the attachment of the superior belly of omohyoid
hyoid
what is the attachment of the inferior belly of omohyoid
clavicle
what is the innervation of the infrahyoid/strap muscles
ansa cervicalis
except thyrohyoid which is innervated by C1 via hypoglossal nerve
what nerves so far have been innervated by C1 via the hypoglossal nerve
thyrohyoid
geniohyoid
on the left, the common carotid artery is a branch of what
arch of aorta
on the right the common carotid artery is a branch of what
brachiocephalic artery
what is the standard pattern of branching of the common carotid artery
2 terminal branches - internal and external carotid
where does the common carotid artery branch
between the thyroid cartilage and the hyoid bone, between C3 and C4
at the bifurcation, the internal carotid lies _____ to the external carotid
at the bifurcation, the internal carotid lies external to the external carotid but comes internal as it passes into the skull whereas the external carotid remains on the external surface of the head to supply the face and neck
the internal carotid goes where
passes into the skull to supply brain
the common carotid artery is in the carotid sheath with what
internal jugular vein and vagus nerve
also lymph nodes near vessels
describe the structures of the carotid sheath
internal jugular vein and common carotid artery and between them the vagus nerve
how many branches of the external carotid artery lie in the anterior triangle of the neck
3
what are the 3 anterior branches of the external carotid artery in the anterior triangle of the neck
facial artery, lingual artery and superior thyroid artery
describe the course of the superior thyroid artery
first anterior branch of the external carotid artery. Passes down the neck to the thyroid gland
what is the second anterior branch of the external carotid artery
lingual artery
what is the path of the lingual artery
passes into floor of the oral cavity to supply the tongue
what is the third anterior branch of the external carotid artery
facial artery
what is the path of the facial artery
crosses the anterior surface of the mandible to supply the face
the lingual artery passes close to what nerve
hypoglossal nerve
what branch of the subclavian artery supply the thoracic wall
internal thoracic
what branch of the subclavian artery supplies the brain
vertebral branch
what branch of the subclavian artery supplies structures in the neck
thyrocervical trunk
where are branches of the first part of the subclavian found in the neck
deep in the triangles of the neck
what is cranial nerve CNX
vagus nerve
the vagus nerve will supply structures in the neck via what branch
laryngeal branches
what is the course of the recurrent laryngeal nerve on the left
descends into thorax and wraps around arch of aorta before ascending the neck lying between the oesophagus and the trachea
what is the course of the recurrent laryngeal nerve on the right
wraps around the subclavian artery before ascending the neck lying between the oesophagus and the trachea
what are the laryngeal branches of the vagus nerve
recurrent, external and internal
the vagus goes through the thoracic inlet to the superior mediastinum and carries what kind of innervation to the thorax and abdomen
parasympathetic
what kind of gland is the thyroid gland
endocrine
what is the function of the thyroid gland
regulates metabolic rate
describe the structure of the thyroid gland
2 lobes connected by an isthmus and a capsule
where is the thyroid gland found in the neck
deep in the anterior triangle
what covers the thyroid
infrahyoid muscles
where is the isthmus of the thyroid
over tracheal ring 2 or 3
where are the parathyroid glands found
embedded into posterior surface
what is the arterial supply of the thyroid gland
one superior and one inferior thyroid artery on each side
the superior thyroid is a branch of what
first anterior branch of the external carotid
the inferior thyroid artery is a branch of what
branch of the thyrocervical trunk of subclavian artery
what is the venous drainage of the thyroid gland
superior middle and inferior thyroid vein on each side
where do the superior and middle thyroid veins drain
internal jugular veins
where do the inferior thyroid veins drain
both into left brachiocephalic vein
where does the right inferior thyroid vein drain
left brachiocephalic vein
what are the 3 sets of salivary glands
parotid
submandibular
sublingual
what salivary gland lies in the anterior triangle
submandibular
what vein crosses the submandibular salivary gland
facial vein
what part of the submandibular salivary gland lies in the anterior triangle and where does the rest of it lie
small outer part in anterior triangle - rest is in the floor of the mouth superior to mylohyoid
the submandibular gland passes saliva into the mouth via a duct located where
between the 1st and 2nd lower incisor teeth each side
(either sde of frenelum)
what supplies parasympathetic secretomotor to the submandibular gland
facial nerve CN VII
part of the submandibular gland lies in the anterior triangle of the neck inferior to
mylohyoid
the part of the submandibular gland in the floor of the mouth lies superior to what
mylohyoid
where does the thoracic duct empty lymph
junction of the internal jugular and subclavian veins as they form the brachiocephalic vein