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. Additionally, embryology encompasses the study of congenital disorders that occur before birth, known as teratology. Early embryology was proposed by Marcello Malpighi, and known as preformationism, the theory that organisms develop from pre-existing miniature versions of themselves.
File:Chest.jpg File:Chestxp illustrated.jpg|Human chest radiographic anatomy. Radioanatomy (x-ray anatomy) is anatomy discipline which involves the study of anatomy through the use of radiographic films. The x-ray film represents two-dimensional image of a three-dimensional object due to the summary projection of different anatomical structures onto a planar surface. It requires certain skills for the correct interpretation of such images. Radiological anatomy is a necessary component of training for radiologists as well as medical students.
A medical school is a tertiary educational institution, professional school, or forms a part of such an institution, that teaches medicine, and awards a professional degree for physicians. Such medical degrees include the Bachelor of Medicine, Bachelor of Surgery (MBBS, MBChB, MBBCh, BMBS), Master of Medicine (MM, MMed), Doctor of Medicine (MD), or Doctor of Osteopathic Medicine (DO). Many medical schools offer additional degrees, such as a Doctor of Philosophy (PhD), master's degree (MSc) or other post-secondary education.
Developmental biology is the study of the process by which animals and plants grow and develop. Developmental biology also encompasses the biology of regeneration, asexual reproduction, metamorphosis, and the growth and differentiation of stem cells in the adult organism. The main processes involved in the embryonic development of animals are: tissue patterning (via regional specification and patterned cell differentiation); tissue growth; and tissue morphogenesis.
In a multicellular organism, an organ is a collection of tissues joined in a structural unit to serve a common function. In the hierarchy of life, an organ lies between tissue and an organ system. Tissues are formed from same type cells to act together in a function. Tissues of different types combine to form an organ which has a specific function. The intestinal wall for example is formed by epithelial tissue and smooth muscle tissue.