The brain is a complex organ that serves as the center of the nervous system in humans and many other animals.

Carl Linnaeus (1707-1778) was a Swedish botanist, zoologist, and physician who laid the foundations for modern taxonomy and binomial nomenclature.

Embryology (from Greek ἔμβρυον, embryon, "the unborn, embryo"; and -λογία, -logia) is the branch of animal biology that studies the prenatal development of gametes (sex cells), fertilization, and development of embryos and fetuses.

The heart is a crucial organ in the circulatory system that pumps blood throughout the body.

Histology is the study of the microscopic anatomy of cells and tissues of plants and animals.

The kidney is an essential organ in the human body responsible for filtering waste products and excess water from the bloodstream, producing urine, and maintaining proper levels of electrolytes and fluids.