General Points 4

Question 1

Nerves at risk during a carotid endarterectomy

Answer 1

Hypoglossal nerve
Greater auricular nerve
Superior laryngeal nerve

Question 2

Carotid endarterectomy

Answer 2

The sternocleidomastoid muscle is dissected, with ligation of the common facial vein and then the internal jugular is dissected exposing the common and the internal carotid arteries

Question 3

Internal carotid artery

Answer 3

Posterior - Longus capitis, Pre-vertebral fascia, Sympathetic chain, Superior laryngeal nerve
Medially - External carotid (near origin), Wall of pharynx, Ascending pharyngeal artery
Laterally - Internal jugular vein (moves posteriorly at entrance to skull), Vagus nerve (most posterolaterally)
Anteriorly - Sternocleidomastoid, Lingual and facial veins, Hypoglossal nerve

Branches
Anterior and middle cerebral artery
Ophthalmic artery
Posterior communicating artery
Anterior choroid artery
Meningeal arteries
Hypophyseal arteries

Question 4

JVP

Answer 4

Upward deflections
a wave = atrial contraction
c wave = ventricular contraction
v wave = atrial venous filling

Downward deflections
x wave = atrium relaxes and tricuspid valve moves down
y wave = ventricular filling

Question 5

Cerebral perfusion pressure

Answer 5

= Mean arterial pressure - intra cranial pressure

Question 6

Mean arterial pressure

Answer 6

= Diastolic pressure + 1/3(Systolic pressure - Diastolic pressure)

Question 7

CSF

Answer 7

Lateral ventricles (via foramen of Munro) -> 3rd ventricle -> Cerebral aqueduct (aqueduct of Sylvius) -> 4th ventricle (via foramina of Magendie and Luschka) -> Subarachnoid space -> Reabsorbed into the venous system via arachnoid granulations into superior sagittal sinus

Made up of:
Glucose - 50-80mg/dl
Protein - 15-40 mg/dl
Red blood cells - Nil
White blood cells - 0-3 cells/mm3

Bacterial meningitis - neutrophilia
Viral meningitis - lymphocytosis

Question 8

How many collateral circulations exist as alternative pathways of venous return in superior vena cava obstruction?

Answer 8

There are 4 collateral venous systems:
Azygos venous system
Internal mammary venous pathway
Long thoracic venous system with connections to the femoral and vertebral veins (2 pathways)

Question 9

Popliteal Fossa

Answer 9

Boundaries
Lateral - Biceps femoris above, lateral head of gastrocnemius and plantaris below
Medial - Semimembranosus and semitendinosus above, medial head of gastrocnemius below
Floor - Popliteal surface of the femur, posterior ligament of knee joint and popliteus muscle
Roof - Superficial and deep fascia

Contents
Popliteal artery and vein (most medial), Small saphenous vein, Common peroneal nerve (most lateral), Tibial nerve, Posterior cutaneous nerve of the thigh, Genicular branch of the obturator nerve, Lymph nodes