A: Front of neck Flashcards
Carotid Sheath
Deep fascia surrounding common + internal carotid arteries, internal jugular vein, deep cervical chain of lymph nodes + vagus nerve.
Retropharyngeal space:
Between prevertebral fascia + posterior extension of pretracheal fascia.
Infection here can compress pharynx and result in difficulty swallowing, infection can spread from neck to posterior mediastinum.
Pretracheal space
Lies between inverting layer of cervical fascia + pretracheal fascia.
Third space
Within prevertebral fascia + covers anterior surface of cervical vertebrae. Passes from base of skull into posterior mediastinum.
Boundaries of anterior triangle of neck
Anterior = anterior midline of neck
Posterior = anterior border of SCM
Superior = mandible
Apex = where SCM meets midline
4 smaller triangles in anterior triangle
Submandibular triangle
Submental triangle
Carotid triangle
Muscular triangle
Carotid sinus
Dilation of distal common carotid artery + proximal internal carotid artery.
Contains baroreceptors which detect changes in blood pressure + is innervated by glossopharyngeal nerve.
Sinus hypersensitivity
Excessive decrease in HR and BP as a consequence of pressure on carotid sinus. Leads to cerebral ischaemia - causing fainting.
Internal carotid artery atherosclerosis
Thickening + hardening of artery, with narrowing of lumen by atherosclerotic plaques.
Narrowing + occlusion of internal carotid arteries reduces blood supply to brain –> Transcient Ischaemic attack/ stroke.
External carotid artery branches
Superior thyroid artery
Lingual artery
Facial artery
External carotid artery termination
Posterior to neck of mandible, where it divides into superior temporal artery (which ascends anterior to ear) and maxillary artery (which passes through parotid gland).
How does IJV exit the skull
Through jugular foramen, enters carotid sheath.
Pressure changes in RA effet on IJV?
Cause pulsations since there are no valves between it and heart.
Pulse not palpable but can be seen beneath SCM above medial end of clavicle.
Importance of jugular venous pulse
An important clinical sign indicating functioning of right side of heart.
If pressure in RA is raised, central venous pressure is raised and pulsations in IJV are higher in neck + more visible.
Air embolism of internal jugular vein
complication of a cut wall of this vessel. Air is sucked into vein and air embolism will fill right side of heart with froth which nearly stops blood flow.
Cannot blind clamp IJV during bleeding due to close relationship to vagus + hypoglossal nerves.
Branches of subclavian artery:
Vertebral arteries
Internal thoracic arteries
Risk of subclavian venous access
Can injure subclavian artery/ pleura/ thoracic duct.
You are examining your patient at the bedside. How do you access central venous pressure? What is this known as?
When the patient is sitting at a 45o angle, the height of pulsation of the internal jugular vein (deep to SCM) is measured.
Known as Jugular Venous Pulse (JVP).
You are examining the Jugular Venous Pulse (JVP) of your patient. What would you expect in a normal healthy patient? What is
an abnormal result?
Normally: JVP maybe visible at the level of the sternal notch.
If JVP higher in neck than sternal notch central venous pressure is raised.
Explain why pulsations in the IJV can be used to determine central venous pressure.
Systemic veins (SVC, IVC) drain to the Right Atrium (RA) of heart.
If pressure in RA is raised, central venous pressure is raised.
Changes in pressure in the RA during the cardiac cycle cause pulsations in IJV because there are no valves between IJV and heart.
Therefore, pulsations in the IJV (Jugular Venous Pulse (JVP)) can be used to determine central venous pressure.
The higher the visible pulsations the higher the central venous pressure.
What are the surface landmarks used to insert a central line into the internal jugular vein?
Lateral to pulse of common carotid artery, directly through SCM halfway down neck or in gap between 2 head of SCM.
The external jugular vein is prominent on your patient. What is the surface landmark of the EJV?
On the side of the neck from the angle of mandible,
- crosses superficial surface of SCM.
- posterior border of SCM, pierces investing layer of deep cervical fascia.
- descends to inferior of Posterior Triangle of neck
- terminates in subclavian vein.
The external jugular vein is prominent on the side of the neck of your patient who is sitting up. What may this be a sign of?
Indicates venous pressure is raised.
This increased venous pressure maybe due to heart failure or obstruction of the SVC
Root of neck + its boundaries
Area where inferior part of neck joins superior part of thorax.
Anterior: manubrium of sternum and upper margin of clavicles
Posteriorly: T1 vertebra and upper margin of scapulae.
Submandibular triangle boundaries:
Located between inferior border of mandible and anterior & posterior bellies of digastric muscle
Submental triangle boundaries:
Apex = mandibular symphysis
Base = hyoid bone
Sides = anterior belly of digastric
Carotid triangle boundaries
Superior belly of omohyoid/ posterior belly of digastric/ anterior border of SCM
Muscular triangle boundaries
Superior belly of omohyoid, anterior border of SCM, midline of neck
What is the surface landmark of the bifurcation of the right common carotid artery?
Bifurcates at Upper border of thyroid cartilage
Branches of subclavian artery:
vertebral + internal thoracic arteries
