Cross-sectional tissue layers and cellular structures of a plant leaf.

The knee

The major coronary arteries and cardiac veins supplying and draining the myocardium on the anterior surface of the heart.

Structure of pulmonary alveoli and the capillary network where gas exchange takes place in the lungs.

The nine core anatomical structures of the human eyeball shown in cross-section.

The primary skull base foramina and the cranial nerves that traverse them, viewed from the superior internal cranial base.

The major components of the cardiac electrical conduction pathway involved in impulse delay and ventricular depolarization.