Week 2: Anterior Triangle Flashcards
boundaries of the anterior triangle are?
inferior border of mandible
anterior border of SCM
midline neck
roof of anterior triangle
deep investing fascia around muscles
floor of anterior triangle is formed by
pretracheal fascia
carotid sheath
subdivisions of anterior triangle
submental
submandibular
carotid and muscular triangles
suprahyoid muscles are
digastric
mylohyoid
geniohyoid
stylohyoid
infrahyoid muscles are
sternothyroid
omohyoid
thyrohyoid
sternohyoid
action of suprahyoid muscles
elevate the hyoid and larynx
mylohyoid is innervated by?
CNV3 inferior alveolar branch
digastric muscle is innervated by?
anterior belly - CN V3 (trigeminal) inferior alveolar branch
posterior belly - the digastric branch of the facial nerve (CN VII)
stylohyoid is innervated by?
CN VII
geniohyoid is innervated by?
anterior ramus of C1, hitchhikes with CNXII (hypoglossal)
actions of infrahyoid muscles (strap)
depresses or fixes hyoid bone
superficial infrahyoid muscles are?
sternohyoid
omohyoid
deep infrahyoid muscles are
thyrohyoid
sternothyroid
sternohyoid, sternothyroid and omohyoid are innervated by?
anterior rami of C1-3 through the ansa cervicalis
thyrohyoid innervated by? n
anterior rami of C1, runs with CNXII
thyroid gland is composed of and where does it sit?
left and right lobe
midline isthmus at 3rd tracheal ring
extends from thyroid cartilage - 5th tracheal ring
arterial supply to thyroid gland
superior thyroid artery (1st branchg external CA)
inferior thyroid artery ( branch of thyrocervical trunk from subclavian
venous drainage of thyroid gland
superior, middle, (–>IJV)
inferior thyroid vein (–>subclavian)
where are the parathyroid glands + composition
2 pairs (inferior, superior)
found on posterior surface of thyroid
thyroid and parathyroid glands nerve supply are?
thyroid branches of cervical sympathetic ganglia
what are the 2 types of surgical airway
Cricothyrotomy - which goes through the cricothyroid ligament
Tracheostomy - which goes through the trachea.
implication of neck surgery and the recurrent laryngeal nerves (from CN X)
The right recurrent laryngeal nerve in particular has a close anatomical relationship to the inferior thyroid artery near the inferior pole of thyroid, and it is therefore at risk of injury during surgery in the neck, especially when the artery is being ligated
carotid triangle contains
thyroid gland,
Larynx
pharynx
carotid sheath (& contents)
branches of cervical plexus
superior root of the ansa cervicalis
deep cervical lymph nodes
(parts of) CN XI & XII
where is the carotid sheath
runs from foreman of carotid canal to aortic arch
contents of carotid sheath
medially - CCA, ICA, part of ECA
laterally- IJV
posteriorly - CNX
the common carotid artery L and R branches arise from
L - directly from arch of aorta (2nd branch)
R - branch from brachiocephalic trunk (1st branch of aorta)
what does the carotid SINUS do and where is it?
reacts to changes in blood pressure
enlargement at bifurcation of CCA
what does the carotid BODY do and where is it?
small organ which houses chemoreceptors located at bifurcation of CCA near the carotid sinus
carotid body and sinus are innervated by?
CN IX via carotid sinus nerve & CN X
branches of ECA
superior thyroid
ascending pharyngeal
lingual
facial
occipital
posterior auricular
superficial temporal
maxillary
which are the terminal branches of ECA
superficial temporal
maxillary
ECA mainly supplies?
structures external to cranium (neck, face, head)
IJV drains blood from?
brain
anterior face
cervical viscera
and deep muscles of the neck
veins draining into IJV are
Inferior petrosal sinus
Pharyngeal
Occipital
Facial
Lingual
Superior thyroid
Middle thyroid
what muscle runs across IJV
omohyoid muscle
what does EJV drain?
scalp and face
EJV is formed by?
the union of the posterior division of the retromandibular vein with the posterior auricular vein
veins draining EJV are?
Posterior external jugular
Transverse cervical
Suprascapular
Anterior jugular
where is the EJV?
Begins near the mandibular angle just below or in the parotid gland.
Crosses over SCM
Pierces investing fascia to enter & drain into subclavian vein
where does the AJV arise?
near the hyoid bone formed from the superficial submandibular veins
what does AJV drain into
the external jugular vein or the subclavian vein directly
what innervates platysma muscle
Cervical branch of CN VII
parotid plexus gives rise to what 5 terminal branches of facial nerve
temporal
zygomatic
buccal
marginal mandibular
cervical
Glossopharyngeal CN IX innervation and course
primarily related to the tongue and pharynx.
Leaves through anterior aspect of jugular foramen & travels downward between the IJV & ICA
Vagus CN X course
exits the jugular foramen & travels downward within carotid sheath with IJV & CCA (ICA)
Spinal accessory CN XI supplies?
SCM
trapezius muscles
Spinal accessory CN XI course
exits the jugular foramen & travels downward between the IJV & ICA
It then crosses the lateral surface of the IJV to descend to the posterior triangle of the neck
Hypoglossal Nerve (CNXII) course
passes between the external carotid and jugular vessels and gives off the superior root of the ansa cervicalis and then a branch to the geniohyoid muscle
Transverse cervical nerve (anterior rami C1,2) supplies?
cutaneous innervation over SCM & anterior triangle
Cervical plexus (anterior rami C1, C2-4) supply
infrahyoid muscles
diaphragm (via phrenic)
skin of anterior/lateral neck
inferior head
the brachial plexus starts and ends at?
C5 to T1
brachial plexus branches in the neck
dorsal scapular nerve
C5 phrenic
suprascapular
