1. Surface Anatomy Landmarks

•    Cardiac

o    Apex beat: 5th intercostal space, midclavicular line (LV apex).

o    Heart valves (best auscultated):

    Aortic: 2nd right ICS, sternal edge.

    Pulmonary: 2nd left ICS, sternal edge.

    Tricuspid: lower left sternal edge.

    Mitral: 5th ICS, midclavicular line.

•    Lung borders

o    Anterior: 6th rib midclavicular, 8th rib midaxillary, 10th rib paravertebral.

o    Pleura extends 2 ribs lower than lungs.

•    Major vessels

o    Carotid bifurcation: ~C4 level.

o    Abdominal aorta bifurcation: ~L4 level.

o    Femoral artery: midway between ASIS and pubic symphysis.

2. Cardiac Anatomy

•    Chambers

o    RA: receives from SVC, IVC, coronary sinus.

o    RV: most anterior; forms most of anterior surface.

o    LA: posterior; closely related to oesophagus (important in AF ablation).

o    LV: forms apex and left border.

•    Valves

o    Aortic valve: between LV and aorta.

o    Mitral valve: between LA and LV.

o    Pulmonary valve: between RV and pulmonary artery.

o    Tricuspid valve: between RA and RV.

•    Coronary circulation

o    RCA: supplies RA, RV, inferior wall; AV node (in ~85% right dominant hearts).

o    LAD: anterior wall, septum, apex.

o    LCx: lateral and posterior walls.

3. Neuroanatomy

•    Motor pathways

o    Corticospinal tract: crosses in medullary pyramids → controls contralateral voluntary movement.

•    Sensory pathways

o    Dorsal columns: vibration, proprioception; decussate in medulla.

o    Spinothalamic: pain, temperature; cross at spinal cord level.

•    Cranial nerves (key points)

o    CN III: eye movements, pupil constriction.

o    CN VII: facial expression; upper face spared in UMN lesion.

o    CN VIII: hearing, balance.

o    CN X: swallowing, voice (recurrent laryngeal branch).

4. CNS Blood Supply

•    Circle of Willis

o    Connects anterior and posterior circulations.

o    Main contributors: ICA, basilar artery.

•    Cerebral arteries

o    ACA: medial frontal lobes, paracentral lobule (lower limb).

o    MCA: lateral hemisphere, face/arm motor and sensory cortex, Broca/Wernicke areas.

o    PCA: occipital lobe, visual cortex.

•    Spinal cord

o    Anterior spinal artery: anterior 2/3 (motor, pain/temp).

o    Posterior spinal arteries: dorsal columns.

5. Abdominal Organ Relationships

•    Spleen

o    Lies under ribs 9–11 on left side.

o    Posterolateral, parallel to 10th rib.

•    Liver

o    Right upper quadrant, extends to left midclavicular line.

o    Segmental anatomy important for surgery (Couinaud classification).

•    Gallbladder

o    Below liver; at intersection of right midclavicular line and costal margin (Murphy’s point).

•    Kidneys

o    T12–L3; right lower than left.

•    Pancreas

o    Head: in C of duodenum; body crosses aorta; tail contacts spleen.

Extra Revision Pearls

•    Left atrium is closest to oesophagus → risk during TEE or AF ablation.

•    Vertebral level of umbilicus: L3/L4 dermatome.

•    Sensory decussation (medial lemniscus) in medulla explains crossed patterns in brainstem lesions.

•    Surface marking for appendix: McBurney’s point (1/3 from ASIS to umbilicus).