A: Front of neck practical Flashcards
Name 3 sheets of deep cervical fascia and what they surround
- Investing layer: encircles the neck
- Pretracheal fascia: surrounds oesophagus, trachea and thyroid gland (ensures movement of thyroid gland during swallowing)
- Prevertebral fasica: covers vertebral column and muscles associated
Contents of carotid sheath
- Common carotid artery
- Internal carotid artery
- Internal jugular vein (lateral to carotid artery)
- Deep cervical chain of lymph nodes
- Vagus nerve (posterior to artery)
Name the spacial faces of the neck
Anterior triangle and posterior triangle
Name boundaries of anterior triangle
- Anterior = midline of neck
- Posterior = anterior SCM
- Superior = mandible
- Apex = where SCM and midline meet
Name 4 smaller triangles in anterior triangle + their boundaries
- Submental triangle (unpaired): apex = mandibular symphysis, base = hyoid bone, sides = anterior belly of digastric muscle
- Submandibular triangle: mandible, anterior and posterior bellies of digastric muscle
- Carotid triangle: SCM, posterior belly of digastric, superior belly of omohyoid
- Muscular triangle: midline, superior belly of omohyoid and anterior SCM
Origin of right and left common carotid arteries
- Right: brachiocephalic trunk
- Left: arch of aorta
Where and into what does the common carotid artery bifurcate?
Bifurcates into internal and external carotid arteries at superior border of thyroid cartilage (Adam’s apple)
When and where is the carotid pulse palpated?
During cardiopulmonary resuscitation at carotid sinus
What does carotid sinus detect and what’s its innervation?
- Has baroreceptors to detect changes in BP
- Glossopharyngeal nerve
What characterizes carotid hypersensitivity?
Excessive decrease of BP and HR because of pressure on carotid sinus –> cerebral ischaemia –> fainting
What are the branches of external carotid artery and how does it terminate?
- Branches: lingual, facial, and superior thyroid arteries
- Terminates posterior to neck of mandible by dividing into maxillary (larger, passes through parotid gland) and superficial temporal (anterior to ear) arteries
Explain process of internal carotid artery atherosclerosis and its consequences
- Atherosclerotic plaques (fatty tissue) = thickening and hardening of artery + narrowing of lumen
- Narrowing of ICA –> reduces blood supply to brain
- Can cause Transient Ischaemic Attach (TIA) / Stroke (Cerebrovascular accident (CVA)) –> visual impairment/blindness (retinal artery), motor paralysis, sensory loss
What does internal jugular vein drain and where does it go
- Face, brain and parts of neck
- Exists skull to enter carotid sheath through jugular foramina
- Deep to SCM
- Joins subclavian vein to form brachiocephalic vein
What causes pulsations in IJV? Where can the pulse be seen?
- Pressure changes in right atrium (no valves) –> raises central venous pressure
- Pulse can be seen beneath SCM, above medial clavicle (when patient sitting at 45° = sternal notch)
Explain catherization of IJV
- Performed to obtain central venous access
- Palpate common carotid artery and insert needle into IJV (lateral to artery) either through SCM or in gap between 2 heads of SCM
What does external jugular vein drain and explain its path
- Scalp and face
- Begins at angle of mandible, crosses superficial SCM, pierces investing layer of deep cervical fascia at posterior SCM, descends to inferior of posterior triangle, terminates in subclavian vein
Explain prominence of EJV
- Normally, prominent for a short distance above clavicle when patient lying down
- If EJV is prominent throughout its course on whole side of neck, it means venous pressure is raised –> can indicate heart failure or obstruction of SVC
What does anterior jugular vein drain?
Anterior part of neck
Explain air embolism of IJV
- IJV wall is cut –> air sucked in the vein –> embolism fills right side of heart with froth –> nearly stops blood flow through heart
- Adventitia of vein is attached to carotid sheath –> hinders collapse of vein
- Blind clamping of IJV is prohibited because of close relationship to vagus and hypoglossal nerves
Boundaries of root of neck
Anterior: manubrium and upper margin of clacvicle
Posterior: T1 vertebra and upper margin of scapula
Contents of root of neck
- Upper lobe of lungs (may be punctured during trauma/procedure in root of neck)
- Subclavian arteries
Branches of subclavian artery
- Vertebral artery: ascend in foramen of cervical vertebrae to cranium
- Internal thoracic artery: enters thoracic cavity and descends on inner surface of anterior thoracic wall
What can you do to control bleeding when there’s haemorrhage from the UL?
Occlude subclavian artery (passes over 1st rib)
What is the only tributary to subclavian vein?
EJV
What are the surface landmarks used to insert a central line into the internal jugular vein?
Lateral to the pulse of common carotid artery, through SCM down the neck or between 2 heads of SCM
