Case 1
Question 2 – Brain
f) What does the inferior anastomotic vein (of Labbe) drain into? (1 mark)
Runs from posteroinferiorly from the posterior end of the lateral sulcus to the transverse sinus
Question 3
Name five (5) common variants of the circle of Willis. (5 marks)
• Duplicated, hypoplastic, fenestrated or absent ACOM
• Hypoplastic or absent A1 – two ACAs supplied by one ICA trunk
• Azygos anterior cerebral artery – both A1 segments of the anterior cerebral arteries unite to form a single midline A2 trunk, resulting in no anterior communicating artery.
• Trifurcation of ACA
• Hypoplastic or absent PCOM
• Fetal origin of PCA – where PCOM is larger than P1 segment of ipsilateral PCA
Case 2
Question 2 – Larynx
e) Describe the innervation of the larynx. (4 marks)
Innervated by branches of vagus
Recurrent laryngeal nerve
– provides sensory innervation to infraglottis
– provides motor innervation to all internal muscles (except cricothyroid): thyroarytenoid, posterior cricoarytenoid, lateral cricoarytenoid, transverse and oblique arytenoid
Superior laryngeal nerve
– provides sensory innervation to supraglottis
– external branch provides motor innervation to cricothyroid muscle
Question 3 – Thyroid and Parathyroid
Name three (3) common or important variants of the thyroid gland (excluding vascular variants). (3 marks)
• Ectopic thyroid tissue
• Pyramidal lobe extending to base of tongue
• Thyroglossal cyst or fistula
Name two (2) common or important variants of the parathyroid glands (excluding vascular variants). (2 marks)
• Supernumerary glands (15%)
• Ectopic parathyroid gland – most commonly inferior to inferior pole
Case 3
Question 2 – Thoracic spinal arteries
Frontal selective thoracic spinal angiogram with the catheter in the left T12 branch
c) Which part of the spinal cord does the posterior spinal arteries supply? (1 mark)
Posterior one-third of the spinal cord
d) Describe the origin and course of the anterior spinal artery. (2 marks)
A single artery formed by the union of two small branches arising bilaterally from the vertebral arteries before its termination as the basilar artery.
It descends on the anterior surface of the medulla oblongata and travels in the anterior median fissure, terminating as a twig on the filum terminale (S1 – S2)
e) Which arteries give rise to the segmental medullary and radicular arteries? (5 marks)
PICA
Vertebral arteries
Ascending and deep cervical arteries
Posterior intercostal arteries
Lumbar arteries
Lateral sacral arteries
Artery of Adamkiewicz
Question 3 – Thoracic vertebrae
Name five (5) common or important variants of the thoracic vertebrae. (5 marks)
• Agenesis (absence of ossification centres)
• Block vertebra (failure of segmentation)
• Hemi vertebra (failure of ossification leading to unilateral/dorsal/ventral wedge vertebra)
• Butterfly vertebra (failure of fusion of lateral halves)
– Associated with persistent notochordal tissue, anterior spina bifida
• Hypoplastic vertebra (vascular insufficiency)
https://pubs.rsna.org/doi/pdf/10.1148/radiographics.8.3.3380991
Case 4
Question 2 – Lung segments
e) Name the segments of the left upper lobe. (4 marks)
Apicoposterior segment
Anterior segment
Superior lingual segment
Inferior lingual segment
f) Name the segments of the left lower lobe. (4 marks)
Superior segment
Anteromedial segment
Lateral segment
Posterior segment
Question 3 – Aortic arch branches
List five (5) common or significant variants of aortic arch branches. (5 marks).
• Bovine arch
• Aberrant left + right subclavian artery
• Common origin of left common carotid and left subclavian artery
• Right common carotid arising from aortic arch
• Absence of braciocephalic trunk
Case 5
Question 2 – Liver
b) Name the boundaries of the epiploic foramen (of Winslow). (4 marks)
• Anterior: Hepatoduodenal ligament, containing the hepatic triad (common hepatic artery, vein and common bile duct)
• Posterior: Peritoneum overlying IVC
• Medial: Gastrosplenic ligament and splenorenal ligament
• Superior: Caudate lobe of the liver
• Inferior: Peritoneum overlying the commencement of duodenum and hepatic artery
c) Which liver segments are located between the right and middle hepatic veins? (1 mark)
5 & 8
d) Which liver segments does the left hepatic vein drain? (2 marks)
2, 3 and occasionally segment 4
e) What structure separates segments 2 and 3 from segment 4? (1 mark)
Left hepatic vein
f) Which hepatic vein(s) drain segment 1? (1 mark)
The veins of the caudate lobe vary in number (1 – 5) and drain directly into the inferior vena cava.
g) What structures define the horizontal plane that divides the superior and inferior liver segments? (1 mark)
Portal vein
Question 3
Name five (5) common or important variants of the pancreas and its ducts. (5 marks)
• Pancreas divisum
• Annular pancreas
• Bifid pancreatic tail
• Ectopic pancreas
• Double accessory pancreatic duct
Case 6
Question 3
Name five (5) common or important variants of the male gonads and their development. (5 marks)
• Bell clapper deformity – high attachment of tunica vaginalis on spermatic cord
• Arrest of testicular descent
• Polyorchidism
• Testicular appendage
• Both testes in one scrotal sac
Case 7
Question 3
Name five (5) common or important variants of the arterial supply of the hand. (5 marks)
• Brachioradial artery – high origin from brachial artery (~9%)
• High origin from axillary artery
• Cubital crossover – anastomosis between brachioradial artery and normal brachial artery in cubital fossa
• Contribution of radial or brachioradial artery to formation of the superficial palmar arch
• Persistent median artery
Case 8
Question 3
List five (5) common or important variants of the sciatic nerve? (5 marks)
Variations in the common peroneal and tibial branches:
• Common peroneal nerve piercing piriformis muscle and tibial nerve exiting below
• Common peroneal nerve travelling above piriformis muscle and tibial nerve below
• Common peroneal nerve travelling above piriformis muscle and tibial nerve piercing piriformis muscle
• Both common peroneal nerve and tibial nerve travelling below piriformis muscle separately
• Sciatic nerve courses over the piriformis muscle
• Sciatic nerve pierces piriformis muscle