Station 2&3

Question 1

What are the 5 layers of the scalp?

Remember SCALP

Answer 1

Skin
Connective tissue
Aponeurosis
Loose areolar tissue
Periosteum

Question 2

Why do scalp lacerations bleed profusely?

Answer 2

Connective tissue layer has a rich blood supply (very close to the skin).
The arteries entering the periphery of the scalp bleed from both ends - they have numerous anastomoses between difference arterial branches.

Question 3

Which is more severe, a coronal or a sagittal laceration?

Answer 3

Coronal

Causing a pull of the frontal and occipital bellies of the occipitofrontalis muscle in the anterior and posterior directions

A superficial laceration gapes because of aponeurosis

Question 4

Which layer of the scalp contains the predominant blood supply?

Answer 4

Connective tissue

Question 5

What is the blood supply to the superficial face?

Answer 5

Facial artery
Superficial temporal artery
(branches of the external carotid artery)

Question 6

What is the blood supply to the deep face?

Answer 6

Maxillary artery

Question 7

Where does the maxillary artery course?

Answer 7

Supplied by the ECA
It has three portions, divided up by its relation to the lateral pterygoid muscle.

1st (mandibular) part: posterior to lateral pterygoid muscle (five branches)
2nd (pterygoid or muscular) part: within lateral pterygoid muscle (five branches)
3rd (pterygopalatine) part: anterior to lateral pterygoid muscle (six branches including terminal branch)

Question 8

Why can facial injuries lead to meningitis?

Answer 8

Danger zone of face (mouth/face) - close communication to veins of face that had no valves therefore infection can spread intracranially. Also, a lot of the veins anastomose therefore aiding spread (infra-orbital vein -> pterygoid plexus -> cavernous sinus)

Infection can spread via the angular vein (uppermost segment of the facial vein) which connects to the cavernous sinus via the opthalmic and infraorbital veins leading to a thrombosis with infection in the cavernous sinus due to the lack of valves.

superior/inferior opthalmic veins -> cavernous sinus

infra-orbital vein -> pterygoid plexus and cavernous sinus

Question 9

What is the main vein of the face?

Answer 9

Facial vein

Question 10

What are the six branches of the ECA before it terminates?

Answer 10

Superior thyroid artery
Lingual
Facial
Ascending pharyngeal
Superficial temporal
Posterior auricular
Occipital

Question 11

Where does the ECA end and what does it divide into here?

Answer 11

Parotid gland

Into the maxillary (deep) artery and superficial temporal artery

Question 12

What is a blowout fracture and why does it occur?

Answer 12

It is a fracture of one of the walls of the orbit but the orbit rim remains in tact.
Normally caused by direct blow to the orbit.

Question 13

What is a retrobulbular haemotoma, why is it a sight-threatening emergency? Which structures does it compress?

Answer 13

Orbital trauma leading to bleeding from the opthalmic artery/vein.
Haemorrhage into the potential space within the rigid orbit and around the eye transmits pressure onto the optic nerve, leading to ischaemic necrosis of the ON. Acute orbital compartment syndrome occurs when this results in a compressive optic neuropathy.

Question 14

What are 3 clinical features of a retrobulbular haematoma?

Answer 14

1. Proptosis (exopthalmos)
2. Reduced extra-ocular movements of the eye
3. Loss of vision

Question 15

What do you use to demonstrate increased intra-ocular pressure?

Answer 15

Tonometry

Question 16

What is the treatment of retrobulbar haematoma?

Answer 16

Lateral canthotomy

Drainage of retrobulbar space