Anatomy - Neck Flashcards
Describe the joints between C1 and C2
-atlanto-axial joint has 3 articulations:
2 x lateral atlanto-axial joints = synovial joint between inferior facet of lateral mass of C1 and superior facet of C2 (gliding)
1 x median atlanto-axial joint = synovial joint between dens of C2 and anterior arch of atlas (pivot)
Describe the movements of the head and neck
- rotation occurs at C1 on C2
- flexion and extension occurs at C1 on atlanto-occipital joint (also lateral flexion and rotation)
What ligaments stabilise C1 and C2
-cruciate ligaments of the atlas:
transverse ligament - strong, extends between lateral mass of C1
superior longitudinal band - weak, extends from transverse ligament to occipital bone
inferior longitudinal band - weak, extends from transverse ligament to body of C2
- alar ligament: extends from dens of the axis to the lateral margins of the foramen magnum
- tectorial membrane: superior continuation of the posterior longitudinal ligament
What are the characteristic features of a typical cervical vertebrae
- typical are C3-C6, small, oval body, large vertebral canal, concave on superior surface, convex on inferior surface
- spinous processes are short and bifid (except C1 and C7), facets joints are more horizontal, tp have foramen
Describe C1 vertebra
C1 = atlas:
- anterior arch contains facet for dens
- kidney shaped superior articular facets
- foramen transversarium in transverse process (contains vertebral artery)
- has groove for vertebral artery
Describe C2 vertebra
C2 = axis:
- dens comes off body
- bifid spinous process
- foramen transversarium in transverse process (contains vertebral artery)
- larger superior articular facets
Xray cervical spine: describe the image
bi-facet dislocation of C5-C6
What are the radiological lines to examine in a cervical xray
-4 lines:
anterior vertebral line
posterior vertebral line
spinolaminar line
posterior spinous line
-prevertebral thickness allowed:
7mm at C2
2cm at C7
What are the components of the soft tissue shadow located anterior to the upper cervical vertebrae
anterior longitudinal ligament
prevertebral fascia
retropharyngeal space
Using an xray, indicate where the ligamentous structures
anterior longitudinal ligament
posterior longitudinal ligament
ligamentum flavum
interspinous ligament
supraspinous ligament
What vascular structures can be identified in the neck root
- SVC, left and right brachiocephalic arteries and veins
- carotids and subclavians
branches of external carotid artery
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Superior Thyroid
Ascending Pharyngeal
Lingual
Facial
Occipital
Posterior Auricular
Maxillary
Superficial Temporal
contents of carotid sheath
common carotid artery
internal jugular vein
vagus nerve
Identify the carotid triangle and its boundaries
-subsection of the anterior triangle
-bound by:
superior belly of omohyoid muscle
posterior belly of digastric
anterior border of scm
-contents: common/internal/external carotid arteries
Describe boundaries and contents of the anterior triangle
boundaries:
- anterior: median line of neck
- posterior: anterior border of sternocleidomastoid muscle
- superior: inferior border of the mandible
- apex: jugular notch of manubrium
- roof: subcutaneous tissue containing platysma
- floor: pharynx, larynx, thyroid gland
contents:
- muscles: strap muscles
- lymph nodes
- arteries: common carotid, int/ext carotid, superior thyroid
- veins: brachiocephalic, subclavian
- nerve: recurrent laryngeal
Describe boundaries and contents of the posterior triangle
boundaries:
- anterior = posterior border of scm
- posterior = anterior border of trapezius
- inferior = middle 1/3 clavicle
- apex = where scm and trapezius meet occipital bone
- roof = deep cervical fascia
- floor = middle and posterior scalene muscles
contents:
- nerves: cn 11, brachial plexus, phrenic nerve
- vessels: subclavian artery, ejv
- muscles: inferior omohyoid, ant/mid/post scalene
Describe the location of the thyroid gland
- anteriorly at level of C5-T1, consists of left and right lobes and connecting isthmus in front of tracheal rings 2/3/4
- deep to sternothyroid and sternohyoid muscles
What are the surface marking and contents of the carotid sheath in the neck
- course: runs along a line joining the sternoclavicular joint to a point midway between the mastoid process and mandible angle
- contents: internal jugular vein, vagus nerve, common carotid artery
What structures are at risk by insertion of central IJV line
external carotid artery
common carotid artery
vagus nerve
trachea
lung
thyroid
What is the anatomical relationship of the internal jugular vein to the carotid artery
superiorly IJV lies posterior to ICA
passes down in carotid sheath (vagus between IJV and CCA)
inferiorly IJV lies lateral CCA
What is the course of the internal jugular vein
- formed by continuation of sigmoid sinus, descends in carotid sheath (lies lateral) with internal carotid artery and vagus nerve
- runs deep to 2 head of sternocleidomastoid muscle
- joins subclavian vein posterior to sternal end of clavicle to form the brachiocephalic vein
- surface marking: from earlobe/mastoid to medial end of clavicle
Discuss the anatomy of the right common carotid artery
- brachiocephalic artery bifurcates into the common carotid and subclavian artery behind the sternoclavicular joint
- lies within the carotid sheath, medial to vagus nerve and internal jugular vein
- bifurcates at the level of the thyroid cartilage (C4) into internal and external carotid arteries
What is the course of the right subclavian artery
arises from brachiocephalic trunk
passes over the first rib posterior to the anterior scalene
becomes axillary artery
Name the branches of the external carotid artery: 2 to pass
superior thyroid
ascending pharyngeal
lingual
facial
occipital
posterior auricular
maxillary
superficial temporal
Describe the course of the right and left recurrent laryngeal nerve and what does it supply
- right hooks around the right subclavian artery and becomes the inferior laryngeal nerve
- left hooks around the arch of the aorta and becomes the inferior laryngeal nerve
- supplies motor to all intrinsic muscles of larynx except cricothyroid muscle and sensation below the cords
What is the result of an injury to the recurrent laryngeal nerve
- hoarse voice, if bilateral stridor occurs due to inability to abduct the cords (posterior cricoarythenoids are the only abductor)
- partial lesion causes cords to take the adducted position as per Semons law
What is the innervation of the larynx
vagus nerve gives off superior laryngeal nerve and inferior laryngeal nerve
superior laryngeal nerve divides into internal and external branches
external branch innervates the cricothyroid muscle
internal branch innervates sensation above the cords
inferior laryngeal nerve comes off the recurrent laryngeal nerve division of the vagus nerve
motor: all intrinsic muscles except the cricothyroid muscle
sensory: sensation below the cords
Name the muscles of vocalisation
cricothyroid
thyroarythenoid
posterior cricoarythenoid
lateral cricoarythenoid
transverse and oblique arythenoids
vocalis
What structures in upper airway could lead to airway obstruction
tongue
tonsils
pharynx
epiglottis
glottis
Which cartilage is fully circumferential
cricoid cartilage
What are the landmarks for a cricothyroidotomy
between thyroid cartilage and cricoid cartilage through the cricothyroid membrane
Xray cervical spine: demonstrate boney features of C1 and C2
odontoid process pa
lateral mass of C1 = 1
odontoid process of C2 = 2
atlanto-axial joint of C1-C2 = 3
body of C2 = 4
spinous process of C2 = 5
ramus of mandible = 6
