Schematic illustration showing a cross-sectional view of the mesoesophagus and associated anatomy.

A schematic illustration showing a houseplan from the front.

A schematic illustration showing a sample EMS communications network.

Schematic showing development of fetal brain at 28 days, 49 days, and 3 months.

Schematic illustration showing the components of the sympathetic nervous system, the spinal nerves and the organs they innervate.

Schematic showing developing fetus in amnionic sac with placental attachment.

Schematic illustration of the right atrium showing the inflow of blood from the superior and inferior vena cava.

Schematic showing the relative sizes of red blood cells, lymphocytes, and macrophages.

Stylized image showing a frontal view of a uterus with a blastocyst about to implant into endometrium of the uterus.

Schematic drawing of infant showing body surface areas as percent of whole; used in calculating burn damage.

Schematic of horizontal section of inguinal canal and testis. Drawing shows eight layers of abdominal wall and three evaginations: scrotum, coverings of spermatic cord, and constituents of the cord.

Schematic showing the morula.