THE NECK Flashcards
WHAT ARE THE 3 VERTICAL COLUMNS OF THE NECK
visceral compartment (anterior)
vascular compartment (medial lateral) (2)
vertebral compartment (posterior)
FASCIA
thin casing of connective tissue
provides containment and protection and allows small degree of movement so structures can slide over one another
WHAT IS CONTAINED WITHIN THE VISCERAL COMPARTMENT
trachea, oesophagus, thyroid and parathyroids
WHAT IS CONTAINED WITHIN THE VASCULAR COMPARTMENT
one either side of midline
contains various blood vessels and nerves including the CCA, IJV and vagus nerve (CN X)
WHAT IS CONTAINED WITHIN THE VERTEBRAL COMPARTMENT
cervical vertebrae, spinal cord, neck and back muscles , cervical nerves
WHERE IS SUPERFICIAL FASCIA FOUND
under the skin of the neck surrounding its entirety
contains cutaneous nerves, blood vessels and anterolaterally the platysma muscle
WHAT ARE THE 3 TYPES OF DEEP FASCIA AND WHERE ARE THEY FOUND
investing - encloses muscles e.g SCM and trapezius , also submandibular and parotid glands
pretracheal - limited to anterior neck and has 2 parts - muscular (encloses infrahyoids) and visceral (encloses trachea , oesophagus and thyroid)
prevertebral - surrounds vertebral compartment and pre and post vertebral muscles e.g scalenes
CAROTID SHEATH
surrounds vascular compartment
blends/ has boundaries with all 3 deep fascias
connects cranial cavity with mediastinum
BORDERS OF ANTERIOR TRIANGLE
inferior border of mandible , midline of neck , anterior border of SCM
BORDERS OF POSTERIOR TRIANGLE
posterior border of SCM , middle 1/3 of clavicle , anterior border of trapezius
WHAT IS THE AREA BETWEEN THE TWO HEADS OF SCM KNOWN AS
subclavicular fossa
HOW CAN THE POSTERIOR TRIANGLE BE FURTHER DIVIDED
split in two by the inferior belly of omohyoid as a boundary
- occipital triangle (superior)
- omoclavicular triangle (inferior)
SCM
- origin
- insertion
- innervation
- action
- origin -
sternal head = manubrium
calvicular head = mid 1/3 clavicle - insertion - lateral surface of mastoid process and superior nuchal line
- innervation - CN XI (spinal accessory nerve)
- action - draws head forward (bilateral action) and tilts head to ipsilateral shoulder (unilateral action)
TRAPEZIUS
- origin
- insertion
- innervation
- action
- origin - superior nuchal line , ligementum nuchae , external occipital protuberance and spinous processes (c7-C12)
- insertion - lateral 1/3 of clavicle, acromium process and spine of scapula
- innervation - CN XI (spinal accessory nerve)
- action - assists in rotating scapula during abduction of humerous
WHAT ARE THE 4 SUBDIVISIONS OF THE ANTERIOR TRIANGLE
submental , submandibular , carotid , muscular
WHAT ARE THE 4 SUPRAHYOIDS
mylohyoid
digastric
stylohyoid
geniohyoid
WHAT ARE THE 4 INFRAHYOIDS
sternothyroid
sternohyoid
thyrohyoid
omohyoid
MYLOHYOID MUSCLE
- origin
- insertion
- action
suprahyoid
- mylohyoid line on mandible (bony ridge on internal surface of body)
- body of hyoid
- elevates hyoid
DIGASTIRC MUSCLE
- origin
- insertion
- action
suprahyoid
- has anterior and posterior bellies
anterior :
o - digastric fossa on lower medial mandible
i = intermediate tendon at hyoid
posterior :
o = mastoid notch on medial side of mastoid process
i = intermediate tendon at hyoid
both elevate the hyoid
WHAT INNERVATES THE MYLOHYOID AND DIGASTRIC MUSCLES
CN V3 via inferior alveolar nerve innervates mylohyoid and anterior belly of digastric
CN VII via digastric branch innervates posterior belly
WHAT DO THE INFRAHYOIDS DO
depress or fix hyoid bone
WHAT DO THE SUPRAHYOIDS DO
elevate hyoid bone during swallowing and aid larynx tone production
WHAT ARE THE 2 SUBDIVISIONS OF THE INFRAHYOIDS
superficial - sternohyoid , omohyoid
deep - sternothyroid, thyrohyoid
OMOHYOID MUSCLE
ORIGIN AND INSERTION
has inferior and superior bellies connected via an intermediate tendon
superior belly runs from lateral body of hyoid to tendon and inferior runs from tendon to superior border of scapula
WHAT INNERVATES THE INFRAHYOIDS
sternothyroid, sternohyoid and omohyoid by ansa cervicalis
thyrohyoid by anterior rami of C1
WHAT NECK COMPARTMENT IS THE THYROID GLAND FOUND IN
visceral
WHERE IS THE THYROID GLAND LOCATED
in the neck - extends from thyroid cartilage superiorly to 5th tracheal ring
composed of two lobes R and L connected via isthmus (some people have additional pyramidal lobe in the centre)
ARTERIAL SUPPLY AND VENOUS DRAINAGE OF THE THYROID
arterial - superior and inferior thyroid arteries
venous - superior, inferior and middle thyroid veins
PARATHYROID GLANDS LOCATION AND VASCULATURE
4 glands located on posterior surface of thyroid gland in majority of ptx
arterial - inferior thyroid arteries
venous - superior middle and anterior inferior thyroid veins
BOUNDARIES OF CAROTID TRIANGLE IN ANTERIOR TRIANGLE OF NECK
superior belly of omohyoid , anterior border of SCM and posterior belly of digastric
CONTENTS OF CAROTID TRIANGLE
thyroid , larynx , pharynx , carotid sheath + contents , ansa cervicalis
3 MAIN CONTENTS OF CAROTID SHEATH AND THEIR LOCATION
common carotid medially , IJV laterally and vagus nerve posteriorly
WHERE IS ANSA CERVICALIS USUALLY FOUND
lying on / embedded in anterolateral portion of carotid sheath
may appear to be on IJV
WHERE DO THE RIGHT AND LEFT COMMON CAROTID ARTERIES ARISE FROM
right - branch of brachiocephalic trunk
left - direct branch from aortic arch
WHERE DOES THE CCA BRANCH INTO ICA AND ECA
branches at level of C3/4 (superior border of thyroid cartilage)
CAROTID SINUS
enlargement in bifurcation of CCA containing baroreceptors in wall of ICA
baroreceptors sensitive to stretch therefore important in monitoring BP
CAROTID BODY
small organ which houses chemoreceptors located at bifurcation of CCA next to carotid sinus
chemoreceptors monitor blood O2 , CO2 and pH , they respond more in emergency situations than at rest
INNERVATION OF CAROTID BODY AND SINUS
CN X and CN IX
(vagus and glossopharyngeal)
8 branches of ECA
ascending pharyngeal (medial)
occipital , posterior auricular (posterior )
facial , lingual , superior thyroid (anterior)
maxillary , superficial temporal (terminating)
WHAT AREA DOES THE ECA SUPPLY
scalp and face
7 veins draining into IJV
(some parallel to ECA branches)
inferior petrosal sinus
pharyngeal
occipital
facial
lingual
superior thyroid
middle thyroid
HOW DOES THE IJV END
joins with subclavian vein to become braciocephalic vein (L and R)
inferior end dilates to form the inferior bulb of IJV which houses a valve preventing backflow
WHAT STRUCTURES DOES THE IJV DRAIN BLOOD FROM
brain. , skull , some face and neck
WHAT STRUCTURES DOES THE EJV DRAIN BLOOD FROM
scalp and face
WHERE IS THE EJV FOUND
running superficial to SCM from angle of mandible (where retromandibular and posterior auricular veins join) to mid clavicle
4 VEINS DRAINING INTO EJV
posterior external jugular
transverse cervical
suprascapular
anterior jugular ( arise near hyoid and run R and L of midline)
WHAT DOES ANSA CERVICALIS INNERVATE
infrahyoids
ansa cervicalis = loop originating from anterior rami of c1 to c3
WHAT DOES THE CERVICAL PLEXUS INNERVATE
infrahyoids, diaphragm , anterior and lateral neck skin
AT WHAT POINT DOES THE SUBCLAVIAN VASCULAR STRUCTURES NAME CHANGE TO AXILLARY
at the lateral border of the 1st rib
WHAT DOES THE BRACHIAL PLEXUS INNERVATE
forms 3 trunks that innervate upper limbs
trunks run inbetween anterior scalene and scalene mass
PARIETAL PLEURA
lines inner aspect of thoracic cavity
VISCERAL PLEURA
lines lung itself
CERVICALPLEURA
superior continutation of parietal pleura which forms cup like dome called pleural cupola
SUPRAPLEURAL MEMBRANE (SIBSONS FASCIA)
reinforces cervical pleura and prevents changes in intrathoracic pressure
WHAT ARE THE 3 PARTS OF THE SUBCLAVIAN ARTERY
pre (anterior) scalene, posterior to anterior scalene, lateral to anterior scalene
WHAT ARE THE 3 BRANCHES OF THE PRE SCALENE PORTION OF THE SUBCLAVIAN ARTERY
VIT C D
Vertebral artery
Internal Thoracic artery
Thyrocervical Trunk
THYROCERVICAL TRUNK
branch of the pre scalene portion of the subclavian artery
gives off inferior thyroid artery which supplies viscera of neck and thyroid gland
also gives of transverse cervical artery and suprascapular artery
WHAT IS THE BRANCH THAT COMES OFF THE 2ND PART OF THE SUBCLAVIAN ARTERY
costocervical trunk
VITCD
WHAT IS THE BRANCH THAT COMES OFF THE 3rd PART OF THE SUBCLAVIAN ARTERY
dorsal scapular
VIT CD
SUBCLAVIAN VEIN
- ORIGIN
- CONTRIBUTOR
- END
- originates from the axillary vein
- only contributor is the EJV
- unites with IJV to form the brachiocephalic vein
THORACIC DUCT
major lymphatic drainage channel
enters venous system between IJV and subclavian vein
TWO GROUPS OF PREVERTEBRAL MUSCLES
anterior and posterior
ANTERIOR PREVERTEBRAL MUSCLES
longus coli (flexes neck)
longus capitis
rectus capitis anterior
anterior scalene
(allflex head)
POSTERIOR PREVERTEBRAL MUSCLES
rectus capitis lateralis
splenius capitis
(flex head)
scalene mass (flex neck)
levator scapulae (lifts scapula)
ROOF OF POSTERIOR TRIANGLE
deep cervical fascia (investing layer) , platysma , superficial fascia and skin
FLOOR OF POSTERIOR TRIANGLE
prevertebral fascia surrounding muscles at floor of traingle (scalenes , levator scapulae and splenius capitis)
WHERE WOULD YOU FIND THE BRACHIAL PLEXUS
trunks (3) run between anterior scalene and scalene mass in posterior triangle of neck
WHERE WOULD YOU FIND THE SPINAL ACCESSORY NERVE IN A DISSECTION OF THE NECK
In the posterior triangle , runs posteriorly to both SCM and trapezius. Can be seen running obliquely between these two muscles superiorly to inferiorly
WHAT ARE THE SENSORY BRANCHES OF THE CERVICAL PLEXUS
greater auricular , lesser occipital , transverse cervical and supraclavicular
WHAT ARE THE MOTOR BRANCHES OF THE CERVICAL PLEXUS
ansa cervicalis and the phrenic nerve
WHERE WOULD YOU FIND THE EJV
crossing the SCM , drains into subclavian vein
WHERE WOULD YOU FIND THE ANTERIOR JUGULAR VEIN
run either side of midline
drain into EJV
