Surface anatomy of the neck Flashcards
What is the retropharyngeal space?
- The largest potential space
- Split between the alar fascia
- There is a true Retropharyngeal space which permits the movement of the trachea, oesophagus and larynx during swallowing
- Danger space = posterior to the alar fascia where infection can spread to the mediastinum
What are the health problems associated with the retropharyngeal space?
- Danger space = posterior to the alar fascia where infection can spread to the mediastinum
- Retropharyngeal abscesses
- Dental abscesses can spread tot he mediastinum
What are the borders of the anterior triangle?
- Superior border: Inferior border of the mandible
- Lateral border: Anterior border of the sternocleidomastoid
- Medial border: Sagittal line down the midline of the neck
What are the borders of the posterior triangle?
- Anterior border: Posterior border of the sternocleidomastoid muscle
- Posterior border: Anterior border of the trapezius muscle
- Inferior border: middle 1/3 of the clavicle
If a patient has a neck lump, what are the important things to note?
- Location
- Size and depth
- Tenderness
- Movement
Where is the parotid gland?
Between the:
• Mastoid process: just behind the ear
• Angle of the mandible: edge of the jaw
Which muscles cover the brachiocephalic trunk?
- Right sternohyoid muscle
* Sternothyroid muscle
Describe the parts of the subclavian artery
• Medial border of the anterior scalene at the origin of the subclavian artery
- 3 branches: Vertebral artery, thyrocervical trunk, internal thoracic artery
• Posterior to the anterior scalene:
- 1 branch: costocervical trunk
• lateral border of the anterior scalene
- 1 branch: dorsal scapular artery
It then goes on to form the axillary artery
What level does the common carotid artery bifurcate at?
The level of the thyroid cartilage (internal and external carotid artery)
Describe the covering of the common carotid artery
- Superiorly it is covered by muscles
* Distally it is exposed allowing palpation of the pulse (normally the internal carotid)
What is the baroreceptor reflex?
Passing out because you took both of the carotid pulses at the same time
Where is the carotid body?
Where the carotid artery is dilated (internal carotid)
What is the carotid body?
- Contains special sensory nerves - baroreceptors
- Mainly innervated by glossopharyngeal (becomes carotid sinus nerve) and a bit by the vagus
- Reacts to changes in the arterial blood pressure
- Carotid body is a chemoreceptor (monitors the partial pressure of CO2)
What covers the internal carotid artery?
Carotid sheath
What does the internal carotid supply?
Intercranial structures - brain
What are the branches of the external carotid arteries from inferior to superior?
- Superior thyroid
- Lingual
- Ascending pharyngeal
- Facial
- Occipital
- Posterior auricular
- Superficial temporal and maxillary
What are the terminal branches of the external carotid?
- Superficial temporal
* Maxillary
What is the venous supply of the head and neck?
• Facial veins - superficial - deep • Cervical veins - external jugular vein - anterior jugular vein - vertebral vein • Cranial veins - cerebral vein - Dural venous sinuses - Diplopic veins - emissary veins
What are the cranial veins drained by?
• Dural venous sinus - superior sagittal sinus - inferior sagittal sinus - sinus rectus • Sigmoid sinus - becomes the internal jugular vein
What does the internal jugular vein drain?
Intracranial structures, superficial parts of the head and neck
What is a normal central venous pressure?
<8cm on H2O
What are the complications of central venous catheterisation
- Pneumothorax
- Puncture of subclavian artery
- Nerve injury
Why is the external jugular vein not used?
There is a risk of air embolism
What is the external jugular vein formed from?
- Posterior division of the retromandibular vein
* Posterior auricular vein
What does the external jugular vein drain?
most of the scalp and the side of the face
Describe the route of the external jugular vein
- Descends from the angle of the mandible to the middle of the clavicle
- Crosses the SCM obliquely, deep to the platysma and enters the antero-inferior part of the posterior triangle
- Pierces the investing fascia at the posterior border of the SCM
- Descends and terminates in the subclavian vein
Describe the position of the anterior jugular vein
- Inferior to the hyoid bone
* Right and left anterior jugular arteries join to form the jugular venous arch
What does the anterior jugular vein drain to?
• External jugular
or
• Subclavian
What is Erb’s point?
4 cutaneous branches become superficial • Lesser occipital • Great auricular • Transverse cervical • Supraclavicular
Accessory nerve
- Motor control of the trapezius and SCM
* Passes across the posterior triangle
Lymph nodes in the head
- None in the scalp or face except in the buccal/parotid region
- All drained into the neck
