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Leonard Hayflick

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114-583: Leonard Hayflick (May 20, 1928 – August 1, 2024) was an American anatomist who was Professor of Anatomy at the UCSF School of Medicine , and was Professor of Medical Microbiology at Stanford University School of Medicine. He was also past president of the Gerontological Society of America and was a founding member of the council of the National Institute on Aging (NIA). The recipient of

228-412: A basal lamina , the upper layer of the basement membrane , the lower layer is the reticular lamina lying next to the connective tissue in the extracellular matrix secreted by the epithelial cells. There are many different types of epithelium, modified to suit a particular function. In the respiratory tract there is a type of ciliated epithelial lining; in the small intestine there are microvilli on

342-450: A copulatory organ present in most species. The eggs are surrounded by amniotic membranes which prevents them from drying out and are laid on land, or develop internally in some species. The bladder is small as nitrogenous waste is excreted as uric acid . Turtles are notable for their protective shells. They have an inflexible trunk encased in a horny carapace above and a plastron below. These are formed from bony plates embedded in

456-481: A microscope . Human anatomy, physiology and biochemistry are complementary basic medical sciences, which are generally taught to medical students in their first year at medical school. Human anatomy can be taught regionally or systemically; that is, respectively, studying anatomy by bodily regions such as the head and chest, or studying by specific systems, such as the nervous or respiratory systems. The major anatomy textbook, Gray's Anatomy , has been reorganized from

570-470: A sessile lifestyle). Most animals have bodies differentiated into separate tissues and these animals are also known as eumetazoans . They have an internal digestive chamber, with one or two openings; the gametes are produced in multicellular sex organs, and the zygotes include a blastula stage in their embryonic development . Metazoans do not include the sponges , which have undifferentiated cells. Unlike plant cells , animal cells have neither

684-402: A "treatise on the heart", with vessels carrying all the body's fluids to or from every member of the body. Ancient Greek anatomy and physiology underwent great changes and advances throughout the early medieval world. Over time, this medical practice expanded due to a continually developing understanding of the functions of organs and structures in the body. Phenomenal anatomical observations of

798-486: A 60-year old dogma that all cultured cells are immortal. Hayflick demonstrated that normal cells have a memory and can remember at what doubling level they have reached. He demonstrated that his normal human cell strains were free from contaminating viruses. His cell strain WI-38 soon replaced primary monkey kidney cells and became the substrate for the production of most of the world's human virus vaccines. Hayflick discovered that

912-528: A cell wall nor chloroplasts . Vacuoles, when present, are more in number and much smaller than those in the plant cell. The body tissues are composed of numerous types of cells, including those found in muscles, nerves and skin. Each typically has a cell membrane formed of phospholipids , cytoplasm and a nucleus . All of the different cells of an animal are derived from the embryonic germ layers . Those simpler invertebrates which are formed from two germ layers of ectoderm and endoderm are called diploblastic and

1026-433: A class of arachnids have four pairs of legs; a body of two segments—a cephalothorax and an abdomen . Spiders have no wings and no antennae. They have mouthparts called chelicerae which are often connected to venom glands as most spiders are venomous. They have a second pair of appendages called pedipalps attached to the cephalothorax. These have similar segmentation to the legs and function as taste and smell organs. At

1140-552: A coat of glycoproteins . In more advanced animals, many glands are formed of epithelial cells. Muscle cells (myocytes) form the active contractile tissue of the body. Muscle tissue functions to produce force and cause motion, either locomotion or movement within internal organs. Muscle is formed of contractile filaments and is separated into three main types; smooth muscle , skeletal muscle and cardiac muscle . Smooth muscle has no striations when examined microscopically. It contracts slowly but maintains contractibility over

1254-457: A few species have no limbs and resemble snakes. Lizards have moveable eyelids, eardrums are present and some species have a central parietal eye. Snakes are closely related to lizards, having branched off from a common ancestral lineage during the Cretaceous period, and they share many of the same features. The skeleton consists of a skull, a hyoid bone, spine and ribs though a few species retain

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1368-665: A gift. It became Stanford's medical institution, initially called the Stanford Medical Department and later the Stanford University School of Medicine. In the 1950s, the Stanford Board of Trustees decided to move the school to the Stanford main campus near Palo Alto. The move was completed in 1959. The San Francisco medical campus became Presbyterian Hospital and later California Pacific Medical Center . In

1482-513: A high metabolic rate , a light skeletal system and powerful muscles . The long bones are thin, hollow and very light. Air sac extensions from the lungs occupy the centre of some bones. The sternum is wide and usually has a keel and the caudal vertebrae are fused. There are no teeth and the narrow jaws are adapted into a horn-covered beak. The eyes are relatively large, particularly in nocturnal species such as owls. They face forwards in predators and sideways in ducks. The feathers are outgrowths of

1596-746: A mammal. Humans have a head, neck, trunk (which includes the thorax and abdomen ), two arms and hands, and two legs and feet. Generally, students of certain biological sciences , paramedics , prosthetists and orthotists, physiotherapists , occupational therapists , nurses , podiatrists , and medical students learn gross anatomy and microscopic anatomy from anatomical models, skeletons, textbooks, diagrams, photographs, lectures and tutorials and in addition, medical students generally also learn gross anatomy through practical experience of dissection and inspection of cadavers . The study of microscopic anatomy (or histology ) can be aided by practical experience examining histological preparations (or slides) under

1710-410: A mechanism for remembering what replication level they are at. He interpreted his finding that normal cells are mortal, to be an indication of aging at the cellular level. Hayflick demonstrated for the first time that mortal (normal) and immortal (malignant) mammalian cells existed. Hayflick developed the first normal human diploid cell strains for studies on human aging and for research use throughout

1824-761: A member of twenty scientific and professional societies in which he has held several high offices including President of the Gerontological Society of America from 1982 to 1983. He was a founding member of the Council of the National Institute on Aging, NIH, and chairman of its executive committee. He was a consultant to the National Cancer Institute and the World Health Organization , and was a member of several scientific advisory boards. He

1938-496: A number of branches, including gross or macroscopic anatomy and microscopic anatomy. Gross anatomy is the study of structures large enough to be seen with the naked eye, and also includes superficial anatomy or surface anatomy, the study by sight of the external body features. Microscopic anatomy is the study of structures on a microscopic scale, along with histology (the study of tissues), and embryology (the study of an organism in its immature condition). Regional anatomy

2052-461: A number of research prizes and awards, including the 1991 Sandoz Prize for Gerontological Research, he studied the ageing process for more than fifty years. He is known for discovering that normal human cells divide for a limited number of times in vitro (refuting the contention by Alexis Carrel that normal body cells are immortal ). This is known as the Hayflick limit . His discoveries overturned

2166-420: A pump action in which air is first drawn into the buccopharyngeal region through the nostrils. These are then closed and the air is forced into the lungs by contraction of the throat. They supplement this with gas exchange through the skin which needs to be kept moist. In frogs the pelvic girdle is robust and the hind legs are much longer and stronger than the forelimbs. The feet have four or five digits and

2280-543: A skeleton to support or protect the body. An exoskeleton is a thickened, rigid cuticle which is stiffened by mineralization , as in crustaceans or by the cross-linking of its proteins as in insects . An endoskeleton is internal and present in all developed animals, as well as in many of those less developed. Epithelial tissue is composed of closely packed cells, bound to each other by cell adhesion molecules , with little intercellular space. Epithelial cells can be squamous (flat), cuboidal or columnar and rest on

2394-497: A systems format to a regional format, in line with modern teaching methods. A thorough working knowledge of anatomy is required by physicians, especially surgeons and doctors working in some diagnostic specialties, such as histopathology and radiology . Academic anatomists are usually employed by universities, medical schools or teaching hospitals. They are often involved in teaching anatomy, and research into certain systems, organs, tissues or cells. Invertebrates constitute

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2508-431: A vast array of living organisms ranging from the simplest unicellular eukaryotes such as Paramecium to such complex multicellular animals as the octopus , lobster and dragonfly . They constitute about 95% of the animal species. By definition, none of these creatures has a backbone. The cells of single-cell protozoans have the same basic structure as those of multicellular animals but some parts are specialized into

2622-479: A vertebrate is the vertebral column , formed in the development of the segmented series of vertebrae . In most vertebrates the notochord becomes the nucleus pulposus of the intervertebral discs . However, a few vertebrates, such as the sturgeon and the coelacanth , retain the notochord into adulthood. Jawed vertebrates are typified by paired appendages, fins or legs, which may be secondarily lost. The limbs of vertebrates are considered to be homologous because

2736-693: A vestige of the pelvis and rear limbs in the form of pelvic spurs . The bar under the second fenestra has also been lost and the jaws have extreme flexibility allowing the snake to swallow its prey whole. Snakes lack moveable eyelids, the eyes being covered by transparent "spectacle" scales. They do not have eardrums but can detect ground vibrations through the bones of their skull. Their forked tongues are used as organs of taste and smell and some species have sensory pits on their heads enabling them to locate warm-blooded prey. Crocodilians are large, low-slung aquatic reptiles with long snouts and large numbers of teeth. The head and trunk are dorso-ventrally flattened and

2850-594: A wide range of stretch lengths. It is found in such organs as sea anemone tentacles and the body wall of sea cucumbers . Skeletal muscle contracts rapidly but has a limited range of extension. It is found in the movement of appendages and jaws. Obliquely striated muscle is intermediate between the other two. The filaments are staggered and this is the type of muscle found in earthworms that can extend slowly or make rapid contractions. In higher animals striated muscles occur in bundles attached to bone to provide movement and are often arranged in antagonistic sets. Smooth muscle

2964-472: A year after its founding and for the next 25 years. He developed their technology for growing animal cells in fermentation tanks in which most of their products were produced. Hayflick was one of several prominent biologists featured in the 1995 science documentary Death by Design: The Life and Times of Life and Times . Hayflick died in Sea Ranch, California , on August 1, 2024, at the age of 96. Hayflick

3078-463: Is 30 months in length, accepts 27 students each year, has an acceptance rate of less than 2%. In the 2021 U.S. News & World Report rankings, Stanford was ranked fourth in the nation among medical schools for research. Admission to the MD program at Stanford is highly competitive: in 2019, 6,894 people applied, 422 were interviewed, and 175 accepted for 90 spots. Stanford is one of several schools in

3192-439: Is also known for his discovery of the cause of primary atypical pneumonia (" walking pneumonia ") in humans. The etiological agent was first thought to be a virus, but Hayflick showed that it was, in fact, a mycoplasma , a member of the smallest free-living class of microorganisms. The etiological agent was named by him as Mycoplasma pneumoniae , and was first grown by Hayflick on a medium he developed and that bears his name. It

3306-541: Is commonly taken to refer to human anatomy . However, substantially similar structures and tissues are found throughout the rest of the animal kingdom, and the term also includes the anatomy of other animals. The term zootomy is also sometimes used to specifically refer to non-human animals. The structure and tissues of plants are of a dissimilar nature and they are studied in plant anatomy . The kingdom Animalia contains multicellular organisms that are heterotrophic and motile (although some have secondarily adopted

3420-473: Is found in the walls of the uterus , bladder , intestines , stomach , oesophagus , respiratory airways , and blood vessels . Cardiac muscle is found only in the heart , allowing it to contract and pump blood round the body. Nervous tissue is composed of many nerve cells known as neurons which transmit information. In some slow-moving radially symmetrical marine animals such as ctenophores and cnidarians (including sea anemones and jellyfish ),

3534-429: Is inherently tied to developmental biology , embryology , comparative anatomy , evolutionary biology , and phylogeny , as these are the processes by which anatomy is generated, both over immediate and long-term timescales. Anatomy and physiology , which study the structure and function of organisms and their parts respectively, make a natural pair of related disciplines, and are often studied together. Human anatomy

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3648-540: Is known for his research in cell biology , virus vaccine development, and mycoplasmology . In 1962 he discovered that, contrary to the prevailing belief at the time, cultured normal human and animal cells have a limited capacity for replication. This discovery, known as the Hayflick limit , overturned a long-held belief bolstered by Alexis Carrel 's work in the early 20th century that claimed that normal cells would proliferate continuously in culture. Hayflick found that only cancer cells are immortal and that normal cells have

3762-587: Is now used for the production of all of the Rubella Virus vaccine used in the Western Hemisphere. WI-38, or new diploid cell strains, are used today for the manufacture of most human virus vaccines produced throughout the world including those for poliomyelitis , rubella, rubeola, varicella, mumps, rabies, adenoviruses and hepatitis A. Over one billion vaccinees have received vaccines produced on WI-38 or foreign versions of Hayflick's original WI-38. Hayflick

3876-655: Is now used worldwide for mycoplasma isolation and research. Hayflick is the recipient of more than twenty-five major awards including the $ 20,000 Brookdale Award and the Kleemeier Award from the Gerontological Society of America, the Biomedical Sciences and Aging Award from the University of Southern California, The Karl August Forster Lectureship of the Academy of Sciences and Literature and the University of Mainz, Germany,

3990-399: Is one of the essential basic sciences that are applied in medicine, and is often studied alongside physiology . Anatomy is a complex and dynamic field that is constantly evolving as discoveries are made. In recent years, there has been a significant increase in the use of advanced imaging techniques, such as MRI and CT scans , which allow for more detailed and accurate visualizations of

4104-583: Is one of the most cited contemporary scientists in the world in the fields of biochemistry, biophysics, cell biology, enzymology, genetics and molecular biology. Hayflick is the author of over 275 scientific papers, book chapters and edited books of which four papers are among the 100 most cited scientific papers of the two million papers published in the basic biomedical sciences from 1961 to 1978. The inverted microscope that Hayflick modified for use in his tissue culture and mycoplasma work and on which all other such microscopes have been modeled has been acquired by

4218-483: Is quite distinct from physiology and biochemistry , which deal respectively with the functions of those parts and the chemical processes involved. For example, an anatomist is concerned with the shape, size, position, structure, blood supply and innervation of an organ such as the liver; while a physiologist is interested in the production of bile , the role of the liver in nutrition and the regulation of bodily functions. The discipline of anatomy can be subdivided into

4332-489: Is startlingly rapid". Between 1275 and 1326, the anatomists Mondino de Luzzi , Alessandro Achillini and Antonio Benivieni at Bologna carried out the first systematic human dissections since ancient times. Mondino's Anatomy of 1316 was the first textbook in the medieval rediscovery of human anatomy. It describes the body in the order followed in Mondino's dissections, starting with the abdomen, thorax, head, and limbs. It

4446-658: Is the largest stem cell and regenerative medicine facility in North America. The Stem Cell Research Building is the first of the planned Stanford Institutes of Medicine. In addition to research facilities, it houses offices for faculty from the Stanford Cancer Center and "hotel space" offices for visiting researchers. The School of Medicine has reversed the traditional teaching method of classroom time being reserved for lectures and problem-solving exercises being completed outside of school as homework; with funding from

4560-399: Is the study of the interrelationships of all of the structures in a specific body region, such as the abdomen. In contrast, systemic anatomy is the study of the structures that make up a discrete body system—that is, a group of structures that work together to perform a unique body function, such as the digestive system. Anatomy can be studied using both invasive and non-invasive methods with

4674-411: Is the vertebral column, composed of articulating vertebrae which are lightweight yet strong. The ribs attach to the spine and there are no limbs or limb girdles. The main external features of the fish, the fins , are composed of either bony or soft spines called rays, which with the exception of the caudal fins , have no direct connection with the spine. They are supported by the muscles which compose

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4788-590: The Hippocratic Corpus , an Ancient Greek medical work written by unknown authors. Aristotle described vertebrate anatomy based on animal dissection . Praxagoras identified the difference between arteries and veins . Also in the 4th century BCE, Herophilos and Erasistratus produced more accurate anatomical descriptions based on vivisection of criminals in Alexandria during the Ptolemaic period . In

4902-571: The American Academy of Anti-Aging Medicine . Hayflick has written numerous articles criticizing both the feasibility and desirability of human life extension , which have provoked responses critical of his views. Hayflick was born May 20, 1928, in Philadelphia, Pennsylvania . He received his Ph.D. at the University of Pennsylvania in 1956. After receiving a post-doctoral fellowship for study at

5016-584: The Robert Wood Johnson Foundation , school leaders are heading up a collaboration on the use of the "flipped classroom" approach to content delivery. The School of Medicine also has a long history of educating physician assistants (PAs). Stanford University partnered with Foothill College in 1971 to form the Primary Care Associate Program (PCAP) which has graduated more than 1,500 PAs. The last PCAP class graduated in 2018. Today,

5130-527: The Smithsonian National Museum of American History . Anatomy Anatomy (from Ancient Greek ἀνατομή ( anatomḗ )  ' dissection ') is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old science, having its beginnings in prehistoric times. Anatomy

5244-557: The Stanford University School of Medicine , Stanford, California. Hayflick resigned from Stanford in 1976 in protest to the behavior of a few of its administrators who were later shown to have wrongly accepted the beliefs of an NIH accountant who was unable to understand the unique concept of title to a self-duplicating biological system. Hayflick sued the NIH, who later agreed that the issue was in dispute. The behavior of Stanford and

5358-506: The Triassic period. There is one living species, Sphenodon punctatus . The skull has two openings (fenestrae) on either side and the jaw is rigidly attached to the skull. There is one row of teeth in the lower jaw and this fits between the two rows in the upper jaw when the animal chews. The teeth are merely projections of bony material from the jaw and eventually wear down. The brain and heart are more primitive than those of other reptiles, and

5472-518: The University of Texas Medical Branch in Galveston under the tutelage of the renowned cell culturist Charles M. Pomerat (1905–1964), he returned to Philadelphia, where he spent ten years as an Associate Member of the Wistar Institute and two years as an Assistant Professor of Research Medicine at the University of Pennsylvania . In 1968, Hayflick was appointed Professor of Medical Microbiology at

5586-400: The epidermis and are found in localized bands from where they fan out over the skin. Large flight feathers are found on the wings and tail, contour feathers cover the bird's surface and fine down occurs on young birds and under the contour feathers of water birds. The only cutaneous gland is the single uropygial gland near the base of the tail. This produces an oily secretion that waterproofs

5700-529: The extracellular matrix . Often called fascia (from the Latin "fascia," meaning "band" or "bandage"), connective tissues give shape to organs and holds them in place. The main types are loose connective tissue, adipose tissue , fibrous connective tissue, cartilage and bone. The extracellular matrix contains proteins , the chief and most abundant of which is collagen . Collagen plays a major part in organizing and maintaining tissues. The matrix can be modified to form

5814-461: The mouthparts . The thorax has three pairs of segmented legs , one pair each for the three segments that compose the thorax and one or two pairs of wings . The abdomen is composed of eleven segments, some of which may be fused and houses the digestive , respiratory , excretory and reproductive systems. There is considerable variation between species and many adaptations to the body parts, especially wings, legs, antennae and mouthparts. Spiders

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5928-400: The stomach . All vertebrates have a similar basic body plan and at some point in their lives, mostly in the embryonic stage, share the major chordate characteristics: a stiffening rod, the notochord ; a dorsal hollow tube of nervous material, the neural tube ; pharyngeal arches ; and a tail posterior to the anus. The spinal cord is protected by the vertebral column and is above

6042-520: The 1980s, the Medical Center launched a major expansion program. A new hospital was added in 1989 with 20 new operating rooms, state of the art intensive care and inpatient units, and other technological additions. The Beckman Center for Molecular and Genetic Medicine opened in May 1989 as an interdisciplinary center focusing on the molecular and genetic basis of disease. The Lucile Packard Children's Hospital

6156-420: The 2nd century, Galen of Pergamum , an anatomist, clinician , writer, and philosopher, wrote the final and highly influential anatomy treatise of ancient times. He compiled existing knowledge and studied anatomy through the dissection of animals. He was one of the first experimental physiologists through his vivisection experiments on animals. Galen's drawings, based mostly on dog anatomy, became effectively

6270-460: The Greek ἀνατομή anatomē "dissection" (from ἀνατέμνω anatémnō "I cut up, cut open" from ἀνά aná "up", and τέμνω témnō "I cut"), anatomy is the scientific study of the structure of organisms including their systems, organs and tissues . It includes the appearance and position of the various parts, the materials from which they are composed, and their relationships with other parts. Anatomy

6384-515: The NIH was later condemned by 85 prominent biologists who viewed him as having been "exonerated" by subsequent events. In 1982 he moved to the University of Florida , Gainesville, where he became Director of the Center for Gerontological Studies and Professor of Zoology in the College of Liberal Arts and Sciences and Professor of Microbiology and Immunology in the College of Medicine. In 1988, Hayflick joined

6498-667: The Pacific (also known as California Wesleyan College), Cooper established the Medical Department of the University of the Pacific, the first medical school on the West Coast , in 1858, on Mission Street near 3rd Street in San Francisco. However, in 1862 Cooper died, and without his leadership, the Medical Department of the University of the Pacific became moribund. In 1870, Cooper's nephew, Levi Cooper Lane , reactivated and reorganized

6612-806: The Regenerative Medicine Secretariat for his "...discovery of the finite replicative capacity of normal human diploid cells..." A third Annual Hayflick Lecture was established at the Friedrich Schiller University in 2013. Hayflick was a Fellow of the American Association for the Advancement of Science , an Honorary Member of the Tissue Culture Association and, according to the Institute of Scientific Information,

6726-824: The Samuel Roberts Noble Foundation Research Recognition Award, the Lifetime Achievement Award of the Society for In Vitro Biology, the Sandoz Prize from the International Association of Gerontology , and the Presidential Award from The International Organization for Mycoplasmology . Hayflick, together with Paul Moorhead, were awarded the prestigious John Scott Award in 2014. This is the oldest scientific award in

6840-566: The Stanford School of Medicine offers a Master of Science in PA Studies program that seeks to train highly qualified clinical PAs who can practice in any area of medicine and also be leaders in community health, research, and medical education. The program offers a novel approach to curriculum delivery and expanded clinical opportunities as well as interprofessional education, with PA students taking courses side by side with MD students. The program

6954-690: The United States to use the multiple mini-interview system, developed at McMaster University Medical School in Canada, to evaluate candidates. Along with the School of Humanities and Science, the Stanford School of Medicine also runs the Biosciences PhD Program, which was ranked first in 2019 among graduate programs in the biological sciences by U.S. News & World Report . In its graduate school specialties, according to U.S. News for 2019, Stanford

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7068-559: The United States, established in 1823 in honor of Benjamin Franklin. In the mid-1990s, Hayflick was recruited by Geron founder Michael D. West to join the company's Scientific Advisory Board. In 1997, Hayflick was elected Academician and Foreign Member of the Ukrainian Academy of Medical Sciences. In 1998 he was elected corresponding member of the Société de Biologie of France. In 1999, he

7182-473: The University of the Pacific's medical department, and, in 1882, Lane donated a new building at the intersection of Webster and Sacramento Streets and established the department as a separate school, the Cooper Medical College. Lane built a hospital and a nursing school and made provision for the creation of Lane Medical Library . In 1908, Cooper Medical College was deeded to Stanford University as

7296-531: The arts and sciences from the Ptolemaic dynasty of Egypt helped raise Alexandria up, further rivalling other Greek states' cultural and scientific achievements. Some of the most striking advances in early anatomy and physiology took place in Hellenistic Alexandria. Two of the most famous anatomists and physiologists of the third century were Herophilus and Erasistratus . These two physicians helped pioneer human dissection for medical research, using

7410-490: The atria were parts of the heart. Herophilus's knowledge of the human body has provided vital input towards understanding the brain, eye, liver, reproductive organs, and nervous system and characterizing the course of the disease. Erasistratus accurately described the structure of the brain, including the cavities and membranes, and made a distinction between its cerebrum and cerebellum During his study in Alexandria, Erasistratus

7524-518: The basis of sense organs and there is a central nervous system (brain and spinal cord) and a peripheral nervous system . The latter consists of sensory nerves that transmit information from sense organs and motor nerves that influence target organs. The peripheral nervous system is divided into the somatic nervous system which conveys sensation and controls voluntary muscle , and the autonomic nervous system which involuntarily controls smooth muscle , certain glands and internal organs, including

7638-462: The body and they swim by undulating their body from side to side. Reptiles are a class of animals comprising turtles , tuataras , lizards , snakes and crocodiles . They are tetrapods , but the snakes and a few species of lizard either have no limbs or their limbs are much reduced in size. Their bones are better ossified and their skeletons stronger than those of amphibians. The teeth are conical and mostly uniform in size. The surface cells of

7752-427: The body's structures. The discipline of anatomy is divided into macroscopic and microscopic parts. Macroscopic anatomy , or gross anatomy, is the examination of an animal's body parts using unaided eyesight. Gross anatomy also includes the branch of superficial anatomy . Microscopic anatomy involves the use of optical instruments in the study of the tissues of various structures, known as histology , and also in

7866-399: The brain, appreciated the division between cerebellum and cerebrum and recognized that the brain was the "seat of intellect" and not a "cooling chamber" as propounded by Aristotle Herophilus is also credited with describing the optic, oculomotor, motor division of the trigeminal, facial, vestibulocochlear and hypoglossal nerves. Incredible feats were made during the third century BCE in both

7980-516: The cadavers of condemned criminals, which was considered taboo until the Renaissance—Herophilus was recognized as the first person to perform systematic dissections. Herophilus became known for his anatomical works, making impressive contributions to many branches of anatomy and many other aspects of medicine. Some of the works included classifying the system of the pulse, the discovery that human arteries had thicker walls than veins, and that

8094-418: The dermis which are overlain by horny ones and are partially fused with the ribs and spine. The neck is long and flexible and the head and the legs can be drawn back inside the shell. Turtles are vegetarians and the typical reptile teeth have been replaced by sharp, horny plates. In aquatic species, the front legs are modified into flippers. Tuataras superficially resemble lizards but the lineages diverged in

8208-402: The digestive and reproductive systems. Herophilus discovered and described not only the salivary glands but also the small intestine and liver. He showed that the uterus is a hollow organ and described the ovaries and uterine tubes. He recognized that spermatozoa were produced by the testes and was the first to identify the prostate gland. The anatomy of the muscles and skeleton is described in

8322-402: The egg-laying monotremes , the platypus and the echidnas of Australia. Most other mammals have a placenta through which the developing foetus obtains nourishment, but in marsupials , the foetal stage is very short and the immature young is born and finds its way to its mother's pouch where it latches on to a teat and completes its development. Humans have the overall body plan of

8436-523: The end of each male pedipalp is a spoon-shaped cymbium that acts to support the copulatory organ . In 1600 BCE, the Edwin Smith Papyrus , an Ancient Egyptian medical text , described the heart and its vessels, as well as the brain and its meninges and cerebrospinal fluid , and the liver , spleen , kidneys , uterus and bladder . It showed the blood vessels diverging from the heart. The Ebers Papyrus ( c.  1550 BCE ) features

8550-467: The epidermis are modified into horny scales which create a waterproof layer. Reptiles are unable to use their skin for respiration as do amphibians and have a more efficient respiratory system drawing air into their lungs by expanding their chest walls. The heart resembles that of the amphibian but there is a septum which more completely separates the oxygenated and deoxygenated bloodstreams. The reproductive system has evolved for internal fertilization, with

8664-413: The epidermis is normally formed of epithelial cells and secretes an extracellular matrix which provides support to the organism. An endoskeleton derived from the mesoderm is present in echinoderms , sponges and some cephalopods . Exoskeletons are derived from the epidermis and is composed of chitin in arthropods (insects, spiders, ticks, shrimps, crabs, lobsters). Calcium carbonate constitutes

8778-429: The epithelial lining and in the large intestine there are intestinal villi . Skin consists of an outer layer of keratinized stratified squamous epithelium that covers the exterior of the vertebrate body. Keratinocytes make up to 95% of the cells in the skin . The epithelial cells on the external surface of the body typically secrete an extracellular matrix in the form of a cuticle . In simple animals this may just be

8892-610: The equivalent of tissues and organs. Locomotion is often provided by cilia or flagella or may proceed via the advance of pseudopodia , food may be gathered by phagocytosis , energy needs may be supplied by photosynthesis and the cell may be supported by an endoskeleton or an exoskeleton . Some protozoans can form multicellular colonies. Metazoans are a multicellular organism, with different groups of cells serving different functions. The most basic types of metazoan tissues are epithelium and connective tissue, both of which are present in nearly all invertebrates. The outer surface of

9006-589: The etiological agent of primary atypical pneumonia (also called "walking pneumonia") was not a virus as previously believed. He was the first to cultivate the causative organism called a mycoplasma , the smallest free-living organism, which Hayflick isolated on a unique culture medium that bears his name. He named the organism Mycoplasma pneumoniae . In 1959, Hayflick developed the first inverted microscope for use in cell culture research. To this day, all inverted microscopes used in cell culture laboratories worldwide are descended from this prototype. His microscope

9120-458: The faculty of the University of California, San Francisco, where he was Professor of Anatomy. Hayflick was a member of numerous national and international scientific and public boards of directors and committees. He has been on the Editorial Boards of more than ten professional journals. Hayflick was Editor-in-Chief of the international journal "Experimental Gerontology" for 13 years. He was

9234-405: The father of microscopical anatomy, discovered that plants had tubules similar to those he saw in insects like the silk worm. He observed that when a ring-like portion of bark was removed on a trunk a swelling occurred in the tissues above the ring, and he unmistakably interpreted this as growth stimulated by food coming down from the leaves, and being captured above the ring. Arthropods comprise

9348-435: The feathers when the bird preens . There are scales on the legs, feet and claws on the tips of the toes. Mammals are a diverse class of animals, mostly terrestrial but some are aquatic and others have evolved flapping or gliding flight. They mostly have four limbs, but some aquatic mammals have no limbs or limbs modified into fins, and the forelimbs of bats are modified into wings. The legs of most mammals are situated below

9462-443: The features of ancient fish. They have a bony skeleton, are generally laterally flattened, have five pairs of gills protected by an operculum , and a mouth at or near the tip of the snout. The dermis is covered with overlapping scales . Bony fish have a swim bladder which helps them maintain a constant depth in the water column, but not a cloaca. They mostly spawn a large number of small eggs with little yolk which they broadcast into

9576-488: The goal of obtaining information about the structure and organization of organs and systems. Methods used include dissection , in which a body is opened and its organs studied, and endoscopy , in which a video camera -equipped instrument is inserted through a small incision in the body wall and used to explore the internal organs and other structures. Angiography using X-rays or magnetic resonance angiography are methods to visualize blood vessels. The term "anatomy"

9690-482: The head. The dermis is covered with separate dermal placoid scales . They have a cloaca into which the urinary and genital passages open, but not a swim bladder . Cartilaginous fish produce a small number of large, yolky eggs. Some species are ovoviviparous and the young develop internally but others are oviparous and the larvae develop externally in egg cases. The bony fish lineage shows more derived anatomical traits, often with major evolutionary changes from

9804-512: The human body were made, which contributed to the understanding of the brain, eye, liver, reproductive organs, and nervous system. The Hellenistic Egyptian city of Alexandria was the stepping-stone for Greek anatomy and physiology. Alexandria not only housed the biggest library for medical records and books of the liberal arts in the world during the time of the Greeks but was also home to many medical practitioners and philosophers. Great patronage of

9918-492: The largest phylum of invertebrates in the animal kingdom with over a million known species. Insects possess segmented bodies supported by a hard-jointed outer covering, the exoskeleton , made mostly of chitin . The segments of the body are organized into three distinct parts, a head, a thorax and an abdomen . The head typically bears a pair of sensory antennae , a pair of compound eyes , one to three simple eyes ( ocelli ) and three sets of modified appendages that form

10032-399: The length of the sides of fish, and these respond to nearby movements and to changes in water pressure. Sharks and rays are basal fish with numerous primitive anatomical features similar to those of ancient fish, including skeletons composed of cartilage. Their bodies tend to be dorso-ventrally flattened, they usually have five pairs of gill slits and a large mouth set on the underside of

10146-437: The lungs have a single chamber and lack bronchi . The tuatara has a well-developed parietal eye on its forehead. Lizards have skulls with only one fenestra on each side, the lower bar of bone below the second fenestra having been lost. This results in the jaws being less rigidly attached which allows the mouth to open wider. Lizards are mostly quadrupeds, with the trunk held off the ground by short, sideways-facing legs, but

10260-400: The main part of the trunk. The heart has two chambers and pumps the blood through the respiratory surfaces of the gills and on round the body in a single circulatory loop. The eyes are adapted for seeing underwater and have only local vision. There is an inner ear but no external or middle ear . Low frequency vibrations are detected by the lateral line system of sense organs that run along

10374-477: The more developed animals whose structures and organs are formed from three germ layers are called triploblastic . All of a triploblastic animal's tissues and organs are derived from the three germ layers of the embryo, the ectoderm , mesoderm and endoderm . Animal tissues can be grouped into four basic types: connective , epithelial , muscle and nervous tissue . Connective tissues are fibrous and made up of cells scattered among inorganic material called

10488-475: The nerves form a nerve net , but in most animals they are organized longitudinally into bundles. In simple animals, receptor neurons in the body wall cause a local reaction to a stimulus. In more complex animals, specialized receptor cells such as chemoreceptors and photoreceptors are found in groups and send messages along neural networks to other parts of the organism. Neurons can be connected together in ganglia . In higher animals, specialized receptors are

10602-416: The notochord, and the gastrointestinal tract is below it. Nervous tissue is derived from the ectoderm , connective tissues are derived from mesoderm , and gut is derived from the endoderm . At the posterior end is a tail which continues the spinal cord and vertebrae but not the gut. The mouth is found at the anterior end of the animal, and the anus at the base of the tail. The defining characteristic of

10716-428: The only anatomical textbook for the next thousand years. His work was known to Renaissance doctors only through Islamic Golden Age medicine until it was translated from Greek sometime in the 15th century. Anatomy developed little from classical times until the sixteenth century; as the historian Marie Boas writes, "Progress in anatomy before the sixteenth century is as mysteriously slow as its development after 1500

10830-493: The same underlying skeletal structure was inherited from their last common ancestor. This is one of the arguments put forward by Charles Darwin to support his theory of evolution . The body of a fish is divided into a head, trunk and tail, although the divisions between the three are not always externally visible. The skeleton, which forms the support structure inside the fish, is either made of cartilage, in cartilaginous fish , or bone in bony fish . The main skeletal element

10944-670: The shells of molluscs , brachiopods and some tube-building polychaete worms and silica forms the exoskeleton of the microscopic diatoms and radiolaria . Other invertebrates may have no rigid structures but the epidermis may secrete a variety of surface coatings such as the pinacoderm of sponges, the gelatinous cuticle of cnidarians ( polyps , sea anemones , jellyfish ) and the collagenous cuticle of annelids . The outer epithelial layer may include cells of several types including sensory cells, gland cells and stinging cells. There may also be protrusions such as microvilli , cilia, bristles, spines and tubercles . Marcello Malpighi ,

11058-428: The study of cells . The history of anatomy is characterized by a progressive understanding of the functions of the organs and structures of the human body. Methods have also improved dramatically, advancing from the examination of animals by dissection of carcasses and cadavers (corpses) to 20th-century medical imaging techniques, including X-ray , ultrasound , and magnetic resonance imaging . Derived from

11172-741: The tail is laterally compressed. It undulates from side to side to force the animal through the water when swimming. The tough keratinized scales provide body armour and some are fused to the skull. The nostrils, eyes and ears are elevated above the top of the flat head enabling them to remain above the surface of the water when the animal is floating. Valves seal the nostrils and ears when it is submerged. Unlike other reptiles, crocodilians have hearts with four chambers allowing complete separation of oxygenated and deoxygenated blood. Birds are tetrapods but though their hind limbs are used for walking or hopping, their front limbs are wings covered with feathers and adapted for flight. Birds are endothermic , have

11286-401: The toes are often webbed for swimming or have suction pads for climbing. Frogs have large eyes and no tail. Salamanders resemble lizards in appearance; their short legs project sideways, the belly is close to or in contact with the ground and they have a long tail. Caecilians superficially resemble earthworms and are limbless. They burrow by means of zones of muscle contractions which move along

11400-538: The trunk, which is held well clear of the ground. The bones of mammals are well ossified and their teeth, which are usually differentiated, are coated in a layer of prismatic enamel . The teeth are shed once ( milk teeth ) during the animal's lifetime or not at all, as is the case in cetaceans . Mammals have three bones in the middle ear and a cochlea in the inner ear . They are clothed in hair and their skin contains glands which secrete sweat . Some of these glands are specialized as mammary glands , producing milk to feed

11514-442: The vertebrae. Their skulls are mostly broad and short, and are often incompletely ossified. Their skin contains little keratin and lacks scales, but contains many mucous glands and in some species, poison glands. The hearts of amphibians have three chambers, two atria and one ventricle . They have a urinary bladder and nitrogenous waste products are excreted primarily as urea . Amphibians breathe by means of buccal pumping ,

11628-437: The water column. Amphibians are a class of animals comprising frogs , salamanders and caecilians . They are tetrapods , but the caecilians and a few species of salamander have either no limbs or their limbs are much reduced in size. Their main bones are hollow and lightweight and are fully ossified and the vertebrae interlock with each other and have articular processes . Their ribs are usually short and may be fused to

11742-457: The world. Prior to his seminal research, all cultured cell lines were immortal and aneuploid . One of these new cell strains, developed by Hayflick and his colleague Paul Moorhead at the Wistar Institute in Philadelphia , Pennsylvania, called WI-38 , has become the most widely used and highly characterized normal human cell population in the world. Hayflick had found that his normal cell strain WI-38

11856-411: The young. Mammals breathe with lungs and have a muscular diaphragm separating the thorax from the abdomen which helps them draw air into the lungs. The mammalian heart has four chambers, and oxygenated and deoxygenated blood are kept entirely separate. Nitrogenous waste is excreted primarily as urea. Mammals are amniotes , and most are viviparous , giving birth to live young. Exceptions to this are

11970-557: Was Chairman of the Scientific Review Board of the American Federation for Aging Research where he was also a vice president and a Member of the board of directors. He was also recruited by Michael D. West , founder of Geron ( Nasdaq :  GERN ) and current CEO of BioTime , to join the company's Scientific and Clinical Advisory Board, on which he served from 1991–2000. Hayflick was also a consultant at Genentech from

12084-486: Was accessioned by the Smithsonian Institution in 2009. Hayflick developed the first practical method for producing powdered cell culture media in 1965. This method is now used worldwide for the production of many tons of powdered media annually for use in research laboratories and commercial production facilities. The technique is not patented and Hayflick received no remuneration from this invention. Hayflick

12198-469: Was acquired by Stanford in 1908. The medical school moved to the Stanford campus near Palo Alto, California , in 1959. The School of Medicine, along with Stanford Health Care and Lucile Packard Children's Hospital , is part of Stanford Medicine. In 1855, Illinois physician Elias Samuel Cooper moved to San Francisco in the wake of the California Gold Rush . In cooperation with the University of

12312-425: Was also responsible for naming and describing the function of the epiglottis and the heart's valves, including the tricuspid. During the third century, Greek physicians were able to differentiate nerves from blood vessels and tendons and to realize that the nerves convey neural impulses. It was Herophilus who made the point that damage to motor nerves induced paralysis. Herophilus named the meninges and ventricles in

12426-472: Was capable of growing all of the then known human viruses. He hypothesized that because WI-38 was free from contaminating viruses, it could replace the then widely used primary monkey kidney cells, which contained several dangerous contaminating viruses. Indeed, WI-38 became used worldwide for human virus vaccine manufacture, to the benefit of billions of people. Hayflick produced the first oral polio vaccine ever made on his normal human cell strain WI-38. WI-38

12540-549: Was completed in 1991, adding even more diversity to Stanford Medicine. In the early years of the 21st century, the School of Medicine underwent rapid construction to further expand teaching and clinical opportunities. The Li Ka Shing Center for Learning and Knowledge opened in 2010; it serves as the gateway to the School of Medicine as well as providing a new model of medical education by combining biomedical research with clinical education and information technology. The Lorry I. Lokey Stem Cell Research Building also opened in 2010; it

12654-421: Was particularly concerned with studies of the circulatory and nervous systems. He could distinguish the human body's sensory and motor nerves and believed air entered the lungs and heart, which was then carried throughout the body. His distinction between the arteries and veins—the arteries carrying the air through the body, while the veins carry the blood from the heart was a great anatomical discovery. Erasistratus

12768-631: Was presented with the van Weezel Award by the European Society for Animal Cell Technology and the Lord Cohen of Birkenhead Medal by the British Society for Research on Ageing . The American Aging Association established an Annual Hayflick Lectureship in 1997. A second Annual Hayflick Lecture was established by the University of Alabama at Birmingham in 2000. Hayflick was the recipient of the 2001, $ 10,000 Life Extension Prize and Laureate Diploma from

12882-789: Was the author of the book, How and Why We Age , published in August 1994 by Ballantine Books , New York City and available since 1996 as a paperback. This book has been translated into nine languages and is published in Brazil , the Czech Republic , Germany , Hungary , Israel , Japan , Poland , Russia , and Spain . It was a selection of the Book of the Month Club and has sold over 50,000 copies worldwide. Hayflick and his associates have vehemently condemned "anti-aging medicine" and criticized organizations such as

12996-546: Was the standard anatomy textbook for the next century. Stanford University School of Medicine The Stanford University School of Medicine is the medical school of Stanford University and is located in Stanford , California , United States. It traces its roots to the Medical Department of the University of the Pacific , founded in San Francisco in 1858. This medical institution, then called Cooper Medical College ,

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